MCAT Physics & Math COMBINED
First, second, and third harmonics of an open pipe
-number of nodes = which harmonic
second law of thermodynamics
-objects in thermal contact and not in thermal equilibrium will exchange heat energy such that the object with a higher temperature will give off heat energy to the object with a lower temperature until both objects have the same temperature at thermal equilibrium
rotational motion
-occurs when forces are applied against an object in such a way that causes the object to rotate about a fixed point, also known as the fulcrum
circular motion
-occurs when forces cause an object to move in a circular pathway -upon one cycle, displacement is zero.
Resistance
-opposition within any material to the movement and flow of electrons -can be thought of like friction, air resistance, or viscous drag, that OPPOSE MOTION -conductors have LITTLE resistance -insulators have HIGH resistance
resonating
-oscillating with maximum amplitude - occurs when the frequency of the periodic force is equal to the natural frequency of the system
Longitudinal waves
-particles oscillate parallel to the direction of propagation -wave particles are oscillating in the direction of energy transfer Ex: -sounds waves -person moving a piston back and force, causing air molecules to oscillate through cycles of compression and rarefaction along the direction of motion of the wave.
transverse waves
-particles oscillate perpendicular to the direction of propagation Ex: -The wave in a stadium, the people standing up are perpendicular to the motion of the wave -electromagnetic waves, like visible light, microwaves, and x-rays
eddies
-swirls of fluid of varying sizes occurring typically on the downstream side of an obstacle.
capacitance
-the ability of a conductor to store energy in the form of electrically separated charges -the ratio of the magnitude of the charge stored on one plate to the potential difference across the capacitor -if a voltage V is applied across the plates of a capacitor and a charge Q collects on it (Q+ on positive and -Q on negative), capacitance is C=Q/V
specific heat
-the amount of heat energy required to raise one gram of a substance by one degree Celsius or one unit Kelvin Ex: -liquid water is one calorie per gram per unit Kelvin. (1cal/g*K) -specific heat changes according to its phase.
refraction
-the bending of light as it passes from one medium to another and changes speed.
Two-pulley system
-the block is suspended from two ropes, each of which bears half of the block's weight -the weight (load) is balanced by the total tension in the ropes, w/ each rope supporting half the crates weight, so only half the force(effort) is required to lift the crate -decrease in effort causes an increase in mechanical advantage. -to lift an object a certain height in the air (load distance), one must pull through a length a rope (effort distance) equal to twice that displacement. Ex: -the crate must be lifted to a shelf 3 meter above the ground, then both sides of the supporting rope must shorten by 3 meters, and the only way to accomplish this is by pulling 6 meters of rope.
spherical aberration
-the blurring of the periphery of an image as a result of inadequate reflection of parallel beams at the edge of a mirror or inadequate refraction breams at the edge of the lens -this creates an area with multiple images with very slightly different image distances at the edge of the image, which appears blurry.
Archimedes' principle
-the buoyant force on an object is equal to the weight of the fluid displaced by the object.
first law of thermodynamics (law of conservation of energy)
-the change in total internal energy of a system is equal to the amount of energy transferred in the form of heat (Q) to the system minus the amount of energy transferred from the system in the form of work (W) Internal energy can be increased by: -adding heat -doing work ON the system Internal energy can be decreased by: -removing heat -the system doing work
Under what conditions could the continuity equation be applied to human circulation?
-the continuity equation CANNOT be applied to human circulation. -The presence of pulses, the elasticity of the vessels, and the nature of the pressure gradient prevent this. -Poiseuille's law should instead be used for isolated segments.
Concave meniscus
-the curve at a liquid's surface by which one measures the volume of the liquid -liquid level is higher at the sides then in the middle
gauge pressure
-the difference b/w the absolute pressure inside and the atmospheric pressure outside Pgauge = P-Patm = (P0 + ρgz) -Patm -When P0 = Patm, Pgauge = ρgz
mass defect
-the difference between the mass of an atom and the sum of the masses of its protons, neutrons, and electrons -result of matter that has been converted to energy
A block is fully submerged three inches below the surface of a fluid, but is not experiencing any acceleration. What can be said about displaced volume of fluid and the buoyant force?
-the displaced volume is equal to the volume of the block. The buoyant force is equal to the weight of the block, and is equal to the weight of the displaced fluid. Therefore, the block and the fluid its immersed in must have the same density.
Thin film
A film of material that has a thickness on the order of the wavelengths of visible light (about 500 nm).
alternating current
A flow of electric charge that regularly reverses its direction.
friction
A force that opposes motion between two surfaces that are in contact
blackbody
A hypothetical object that absorbs all of the radiation that strikes it. It also emits radiation at a maximum rate for its given temperature. -ideal absorber of all wavelengths of light, which would appear completely black if it were at a lower temperature than its surroundings.
isobaric process
A process that occurs at a constant pressure
positron emission
A radioactive decay process in which a proton in the nucleus is converted into a neutron and a positron and then the positron is emitted from the nucleus
loudness
A sensory characteristic of sound produced by the amplitude (intensity) of the sound wave
closed loop
A system that uses feedback from the input to control the output.
True/False: In a circuit, the number of electrons entering a point and leaving that point are the same.
True, -this is just a restatement of Kirchhoff's junction rule.
True/False: Total distance traveled can never be less than the total displacement
True, since distance is either the same as displacement or has a higher magnitude.
True/False: The units of electric potential energy and electric potential are different.
True: -Electric potential energy is measured in joules (J) -Electric potential and potential difference (voltage) are measured in volts (V).
True/false: -Maxima in diffraction patterns are always equidistant between two minima
True: -Maxima and minima alternate in a diffraction pattern. -A maximum is equidistant between two minima, and a minima is equidistant between two maxima.
True/False: The internal resistance of a battery will lower the amount of current it can provide.
True: -The internal resistance will lower the available voltage for the circuit. -lowering the available voltage will also lower the current for any given resistance
True/False: Nuclear Fission and Fusion both release energy
True: While they may seem like inverses of each other, both of them do in fact release energy.
True/False: Density is a scalar quantity
True: -Density is directionless, and is thus a scalar quantity.
True/False: -Incident angle is always measured with respect to the normal
True: In optics, incident angles are always measured relative to the normal.
electric potential energy equation
U = kqQ/r q = charge 1 Q = charge 2 k = 8.99 x 10^9 r = distance between two charges U = electric potential energy
potential energy stored in a capacitor
U=1/2CV^2
What by what factor would potential energy change if the magnitude of both charges were double and the distance between them was halved?
U=kQq/r multiple by 4 on top and 1/2 on the bottom, therefore U would be increased by a factor of 8
Wave Phase Difference
Used to conceptually explain destructive and constructive interference
Linear motion Equation
V = Vo + at x = Vot + (1/2)at^2 v^2 = Vo^2 + 2ax x = vt
Actual Voltage supplied by a cell to a circuit
V= voltage provided by the cell Ecell= emf of the cell ir(int) = internal resistance of the source of emf.
simple machines
a machine with few moving parts, making it easier to do work there are 6: -lever, pulley, wheel and axle, inclined plane, wedge, and screw)
fluorescence
a material absorbs light at one wavelength and then emits light at a longer wavelength -if one excited a fluorescent substance, such as a rube, emerald, or phosphors found in fluorescent lights, with ultraviolet radiation, it will being to glow with visible light.
Do extra problems with circuits and resistors
bet
electric field equation
E= Fe/q = kQ/r^2 E= electric field magnitude (N/C) Fe=magnitude of the force felt by the test charge q. k=coulomb's constant Q = source charge magnitude r=distance between the charges
image distance on a mirror
i -if an image has a positive distance (i>0), it is a real image, which implies that the image is IN FRONT OF THE MIRROR. -if an image has a negative distance (i>0), it is virtual, and is thus located behind the mirror. -For plane mirrors (flat) r = f = infinite, thus the equation becomes 1/0 + 1/i = 0, which becomes i = -o, saying that the virtual image is at the distance behind the mirror equal to the distance the object is in front of the mirror.
First, second, and third harmonics of a string
number of antinodes = which harmonic
snells law
n₁sinθ₁=n₂sinθ₂ where n is index of refraction -Theta is MEASURED WITH RESPECT FROM THE NORMAL
What are three methods of heat transfer?
conduction, convection, radiation
diverging mirror (convex)
light rays parallel to the principal axis are reflected from the mirror surface
converging mirror (concave)
light rays parallel to the principal axis converge and pass through a single point called focal point.
index of refraction equation
n = c / v c: speed of light in a vacuum v: speed of light in the medium
dipole moment equation
p=qd p=dipole moment q=charge d=distance between charges
condensation
phase change from gas to liquid
boiling/evaporation/vaporization
phase change from liquid to gas
myopia
nearsightedness; lack of foresight corrected by bifocals
daughter nucleus
refers to the nucleus produced as a result of radioactive decay
discharging
release or neutralize the electric charge of (an electric field, battery, or other object).
ultrasonic waves
sound waves with a frequency above 20,000 Hz, outside the range of normal human hearing.
Work function equation
the amount of energy needed to dislodge an electron from the surface of a material W=hft
Law of reflection
the angle of incidence is equal to the angle of reflection
sinusoidal waves
waves where the individual particles oscillate back & forth with a displacement that follows a sinusoidal pattern
melting/fusion
the phase transition from solid to liquid
elastic potential energy
the potential energy of an object that is stretched or compressed
strong nuclear force
the powerful attractive force that binds protons and neutrons together in the nucleus
echolocation
the process of using reflected sound waves to find objects; used by animals such as bats -consequence of the doppler effect
Magnification
the ratio of an object's image size to its real size
Mass Number (A)
the sum of the number of neutrons and protons in an atomic nucleus
boiling point
the temperature at which a substance changes from a liquid to a gas
Half Life
the time taken for the radioactivity of a specified isotope to fall to half its original value.
open systems
-can exchange both matter and energy with the environment. -can be transferred in form of heat or work. Ex: -boiling pot of water -human beings -unconstrained combustion reactions
closed system
-can exchange energy, not NOT matter ex: -gases in vessels with movable pistons -most tested systems are closed or approximate closed systems.
surface tension
-causes the liquid to form a thin but strong layer like a "skin" at the liquid's surface -results from cohesion, the attractive force that a molecule of liquid feels toward other molecules of the same liquid.
equilibrium position
-central point around which waves oscillate
Sign convention for a single lens
-changes only slight for lenses -for both lenses and mirrors, a positive image distance means that the image is real and is located on the real side (R) whereas a negative image distance means that the image is virtual and located on the virtual side.
Capacitors
-characterized by their ability to hold charge at a particular voltage. Ex: -defibrillator
fluids
-characterized by there ability to flow and conform to the shapes of their containers -both liquids and gases are fluids
coefficient of linear expansion
-constant that characterizes how a specific material's length changes as the temperature changes -units of usually inverse K (K^-1), sometimes has inverse C (C^-1)
coefficient of volumetric expansion
-constant that characterizes how a specific material's volume changes as the temperature changes. -equal to 3 times the coefficient of linear expansion for the same material (Beta=3*alpha)
What accounts for the difference between work input and work output in a system that operates at less than 100% efficiency?
-decrease in work is due to nonconservative or external forces that generate or dissipate energy
specific gravity equation
-density of object/density of water -used for determining if an object will sink or float in water
Electric potential energy
-dependent on the relative position of one charge with respect to another charge or to a collection of charges -a decrease in potential energy indicates a MORE STABLE system
current
-flow of POSITIVE charge, even though negative charges are actually moving -any conductive substance may act as a medium through which current can pass
Gamma Decay
-nuclear decay that involves the release of gamma rays -they carry no charge and simply lower the energy of the parent nucleus without changing the mass number or the atomic number. -higher energy state represented by an asterisk
Threshold Frequency (ft)
-minimum frequency of light needed to eject electrons from a metal surface -depends on the type of metal being exposed to radiation -"all or nothing" response; if frequency of the incident photon is less than the threshold frequency (f<fT), than no electron will be ejected because the photons do not have sufficient energy to dislodge the electron from its atom.
Temperature in a resistor
-most conductors have greater resistance at high temperature. -this is due to increased thermal oscillation of the atoms in the conductive material, which produces a greater resistance to electron flow.
What would the meniscus of a liquid that experiences equal cohesive and adhesive forces look like?
-no meniscus would form, liquid surface would be flat
viscous drag
-nonconservative force generated by viscosity force that opposes the motion of an object through a liquid. -highly viscous liquids
isolated systems
-not capable of exchanging energy or matter with their surrounding -total change in internal energy must be zero. -bomb calorimeter attempts to insulate a reaction from the surroundings to prevent energy transfer, and the entire universe can be considered an isolated system because there are no surroundings.
Compare and contrast nuclear fission and fusion in terms of: Size of reactant particles: Change in nuclear mass:
Fission -Large (actinides, lanthinides) -Decrease in Nuclear Mass Fusion -Small (hydrogen, helium) -Increase
Plane Mirrors
Flat reflective surfaces which cause neither convergence nor divergence of reflected light rays. Hence, images produced are upright, virtual, reversed and seem to be as far behind the mirror as the object is in front. (Chem Bridge: Molecules with reversed images are termed Chiral) r = f = ∞ -since no convergence or divergence, the image appears to be the same distance behind the mirror as the object in front of it. -include most of the common mirrors found in our homes. -can be conceptualized as spherical mirrors with an infinite radius of curvature
inviscid
Fluids that have no viscosity On MCAT viscosity is deemed negligible if not specifically stated otherwise
Fundamental frequency
the lowest, and usually most intense, frequency of a complex sound; most often perceived as the sound's basic pitch
Critical angle
the minimum angle of incidence for which a light ray is totally reflected within a medium
Atomic number (Z)
the number of protons in the nucleus of an atom
instantaneous velocity equation
-measures of the average velocity as the change in time approaches zero
electrostatics
-study of stationary charges and the forces that are created by and which act upon these charge.
Ray diagrams for concave (converging) mirrors
(a) Object is placed beyond F (b) Object is placed at F (c) Object is placed between F and mirror
Thomas Young's double-slit experiment
(circa 1800), which predated the development of quantum mechanics by over a century, demonstrated that light can behave as either a wave or a particle. After passing a beam of light through two narrowly spaced slits, Young observed the characteristic light and dark fringes of interference seen when light acts as a wave. More modern versions that add detectors showing which slit the light passes through, however, show that the light passes through one slit or the other, acting as photons; moreover, the interference pattern disappears. A modern variant, called a quantum eraser, demonstrates quantum entanglement (the ability to exchange information over large distances instantaneously).
Converging lenses
(convex) thicker in middle, thinner on ends (magnifying glass). converging lenses (reading glasses) are needed for people who are "farsighted"
aberration of light
(spherical or chromatic) -the alteration or distortion of an image as a result of an imperfection in the optical system.
what is an angstrom
* Metric unit of length one billionth of a meter * A-10^-10 * an angstrom is 1.0 × 10^-10 and this symbol Å (One ten billionth of a meter)
flow rate
* volume per unit time * constant for a closed system * independent of changes in cross-sectional area
perpendicular bisector of the dipole
*equipotential line that lies halfway between +q and -q *electrical potential at any point along this line is zero E = kp/r^3
How does a change in electric potential energy from -4 to -7 reflect on the stability of the observed system?
- a decrease in electric potential energy indicates a MORE STABLE system.
timbre
- the quality of the sound -determined by the natural frequency of the object -Some objects vibrate at a single frequency producing a pure tone -Other objects vibrate at multiple frequencies that have no relation to one another ( not musical)
displacement of a wave
- x - refers to how far a point is from the equilibrium position - expressed as a vector quantity
density of water
-1 g/mL -1 g/cm³ -1000kg/m^3
What is the net charge of an object with one coulomb of electrons and 3 moles of neutrons
-1, neutrons are neutrally charged.
Newton's First Law
-A body either at rest or in motion w/ constant velocity will remain that way unless a new force acts upon it.
How will a charge that is placed at a point of zero electric potential move relative to a source charge?
-A charge will move in such a way to minimize its potential energy -Placing a charge at a point of zero electric potential does not indicate that there is zero potential difference, so the charge may or may not move-and if it moves, it may move toward or away from the source charge depending on the sign of the source and test charge.
What is the behavior of an electric dipole when exposed to an external electric field?
-A dipole will ROTATE within an external electric field such that it will ALIGN with the external electric field.
Zeroth Law of Thermodynamics
-A law that if two systems are separately found to be in thermal equilibrium with a third system, the first two systems are in thermal equilibrium with each other; that is, all three systems are at the same temperature. Also known as thermodynamic equilibrium. -if A is in Thermal equilibrium with B, and B w/ C, then A and C are in thermal equilibrium.
viscosity
-A liquid's resistance to flowing -increased viscosity of a fluid increases its viscous drag, nonconservative force analogous to air resistance Si Units: Pa * s = N*s/M^2
Diffraction gratings
-A material with many slits or tiny ridges that refracts light at different angles into its various frequencies / colors -create colorful colors similar to a prism as the different wavelengths interfere in characteristic patterns Ex: -the organization of the grooves on a CD or DVD act like a diffraction grating, creating an iridescent rainbow pattern on the surface of the disk.
Can a moving object be in equilibrium? why or why not?
-A moving object can be in either translational or rotational equilibrium -translational equilibrium only requires the net force on an object to be zero, its velocity is constant. -The corresponding condition in rotational equilibrium is that net torque equals zero-its angular velocity is constant.
alpha decay
-A nuclear reaction in which an atom emits an alpha particle consisting of two protons and two neutrons. This increases the atomic number by 2 and the mass number by 4.
test charge
-A particle (designated q) with either a positive or negative charge set down within an electric field generated by a point charge. -charge placed in electric field
standing waves
-A pattern of vibration that simulates a wave standing still. -when a string is fixed at both ends, so the only movement of the string is the fluctuation of amplitude at fixed points along the length of the string.
Isobaric process
-A process that occurs at a constant pressure -1st law doesn't reduce to anything different
How to draw ray diagrams for concave mirror
-A ray the strikes the mirror parallel to the axis (normal passing through the center of the mirror) is reflected back through the focal point. A ray that passes through the focal point before reaching the mirror is reflected back parallel to the axis. -Basically, draw the center of curvature, and the radius of curvature, and draw the object in relation to them. Draw a PARALLEL LINE from the top of the object to the mirror, and then through the focal point.
work
-A result of a force moving an object a certain distance. W=F * d = Fdcos(theta)
Ray Diagrams for convex (diverging) mirrors
-A single diverging mirror forms only a virtual, upright, reduced image, regardless of the image of the object -the further away the object, the smaller the image will be. -convenience store security mirrors are examples of these.
static friction
-a friction force that acts on objects that are not moving -between a stationary object and the surface it rests upon.
How does adding or removing a resistor change the total resistance of a circuit with resistors in series? parallel?
-Adding a resistor in series increases the total resistance of a circuit; removing one in series decreases the total resistance in the circuit -adding a resistor in parallel decreases the resistance, while removing one increases it.
As the length of an inclined plane increases, what happens to the force required to move an object the same displacement?
-As length increases, the amount of force necessary to perform the same amount of work (moving the object the same displacement) DECREASE -w=f*d, if w doesn't change, and d increases, F must decrease
paramagnetic
-Atom or substance containing unpaired electrons and is consequently attracted by a magnet. -weakly magnetic Ex: -aluminum, copper, gold
Which type of nuclear decay could be detected in an atomic absorption spectrum?
-Because gamma radiation produces electromagnetic radiation, rather than nuclear fragments, it can be detected on an atomic absorption spectrum.
Resistors in parallel
-Current splits into parallel branches so they add - same voltage drop in each branch b/c all pathways start and end at a common point I1 = I2 + I3 V = V1 = V2 -Reciprocal resistances add Requiv = (R1*R2)/(R1+R2 ) -Equivalent resistance decreases as more resistors are added in parallel -Sum of the currents going into each division must equal the total current going out
What does the threshold frequency depend upon?
-Depends on the chemical composition of the metal (that is, the identity of the metal itself)
How to find where the image is for the lens
-Draw the following rays and find a point where any two intersect. -this point of intersection marks the tip of the image. -If the rays you draw do not appear to intersect, extend them to the same side of the lenses where they came from, creating a virtual image. -Ray parallel to the axis -> refracts through focal point of front face of the lens -Ray through the focal point before reaching lens -> refracts parallel through the axis -Ray to center of lens -> continues straight through with no refraction
Dispersion in a prism
-Due to their different speeds while inside the prism, the various wavelengths of light are refracted to different degrees.
power equation
-E= deltaE/t -SI unit for power is Watt (W), which is equal to J/s
Compare electric potential energy and Coulomb's law to the relationship between gravitational potential energy and the universal law of gravitation
-Electric potential energy is just Coulomb's law multiplied by distance -Gravitational potential energy is just the universal law of gravitation multiplied by distance.
Bohr Model: light absorption and emission
-Electron can be excited by a photon, to get to an excited state, moving from the original orbit to a higher orbit.
What is the direction of electron flow relative to current?
-Electrons flow in the opposite direction of current, b/c they move from a point of lower electric potential to a point of higher electrical potential, thereby reducing their electrical potential energy.
potential energy
-Energy that is stored and held in readiness -potential energy is often said to have the potential to do work
What is the relationship between entropy of a system and its surroundings for any thermodynamic process?
-Entropy of a system and its surroundings will NEVER decrease. -It will either remain zero or increase.
How does the initial length of an object and the amount if expands for a given temperature change relate to one another?
-Expansion is a result of an increase in dimension at all points along an object. If an object is initially longer, it will experience a greater expansion. -This is shown in the equation, since there is a direct relationship between length change and the initial length of an object.
Coulomb's law
-F=K q₁*q₂/r² -magnitude of force between two charges -F=magnitude of the electrostatic force -k=coulombs constant -q1 + q2 are magnitude of the two charges -r=distance between the two charges.
Resistivity
-a measure of the resisting power of a specified material to the flow of an electric current. -measured in ohm-meters -intrinsic resistance to current flow in a material.
Pascal's Principle
-Fluids that are incompressible-that is, fluids with volumes that cannot be reduced by any significant degree through application of pressure-a change in pressure will be transmitted undiminished to every portion of the fluid and to the walls of the containing vessel. Ex: -unopened carton of milk could be considered an incompressible fluid in a closed container, if you were to squeeze the container, the applied pressure would be transmitted through the entire volume of milk
What direction does a negative/positive electrostatic force point?
-For a pair of charges, a negative electrostatic force points from one charge to the other (attractive) while a positive electrostatic force points from one charge away from one another (repulsive).
Focal lengths and radii of curvature for lenses and mirrors
-For both mirrors and lenses, converging species have positive focal lengths and radii of curvature, while diverging species have negative focal local lengths and radii of curvatur. -lenses have two focal lengths and two radii of curvature
What wave phenomenon do diffraction fringes result from?
-Fringes result from destructive or constructive interference
How does gauge pressure relate to the pressure exerted by a column of fluid?
-Gauge pressure is equal to the pressure exerted by a column of fluid plus the ambient pressure above the fluid, minus atmospheric pressure. -When atmospheric pressure is the only pressure above the fluid column, when gauge pressure equals the fluid pressure.
Spherical Mirrors
-Have center of curvature and a radius of curvature -Include concave and convex -For a concave surface, the center of curvature and the radius of curvature are located in front of the mirror. -For a convex surface, the center of curvature and the radius of curvature are behind the mirror.
Phase difference of waves
-How far 'out of step' the oscillations at two points on the same wave are.
Current equation
-I = Q/t I=current in ampere ( 1 A = 1 C/s) Q=amount of charge Q passing through the conductor t=unit time
Power equation
-In electric circuits, energy is supplied by the cell that houses a spontaneous redox reaction, which when allowed to proceed (by closing of a switch), generates a flow of electrons. -these electrons have electrical potential energy, convert that to KE as they move around, driven by the emf of the cell.
How does flow in the venae cavae relate to flow in the main pulmonary artery?
-In theory, there should be equal flow in the venae cavae and the main pulmonary trunk. -In reality, the flow in the venae cavae is actually slightly less than in the pulmonary trunk b/c of the blood entering the right side of the heart is actually from cardiac (coronary) circulation, not systemic circulation.
system of six pulleys
-Increasing the number of pulleys decreases the tension in each segment of rope -this leads to an increase in the mechanical advantage of the setup.
Relationship between instantaneous velocity and instantaneous speed? Average velocity and average speed?
-Instantaneous speed is the magnitude of the instantaneous velocity vector -Average speed and average velocity may be unrelated because speed does not depend on displacement, but is rather the total distance traveled divided by time.
potential difference (voltage)
-Is the driving force that pushes the charge around. Measured in volts (V) -can be produced by an electrical generator, a galvanic (voltaic) cell, and a group of cells wired into a battery.
plane-polarized (linearly polarized) light
-Light in which the elctric fields of all the waves are oriented in the same direction (their electric field vectors are parellel). -Their magnetic field vectors are also parallel, but convention dictates that the plane of the electric field identifies the plane of polarization. -Unpolarized light has a random orientation of its electric field vectors; sunlight and light emitted from a light bulb are prime examples. -Useful for classification of stereoisomers, as the optical activity of a compound, due to presence of chiral centers, causes plane-polarized light to rotate clockwise or counterclockwise by a give number of degrees relative to its concentration (specific rotation).
how does mass defect relate to binding energy?
-Mass defect is related to the binding energy such that there is a transformation of nuclear matter to energy with a resultant loss of matter -related by E=mc^2
Scalars
-Numbers that have magnitude only and no direction Ex: -Distance, Speed, Energy, Pressure, Mass
Fusion
-Occurs when small nuclei combine to form a larger nucleus Ex: -many stars power themselves by fusing four hydrogen nuclei to make one helium nucleus, which can produce 3.85 X 10^26 joules/second, which accounts for the mass defect that arises from the formation of helium nuclei from hydrogen nuclei.
What are the SI units of pressure?
-Pascal -mmHg -torr -atm 1.013 X 10^5 Pa = 760 mmHg = 760 Hg = 1 atm
hydraulic lift
-a mechanical system that uses a liquid under pressure in a closed system to raise heavy objects.
How does the application of a polarized filter impact the wavelength of light passing through the filter?
-Plane polarization has no effect on the wavelength (or frequency or speed) of light -Polarization DOES affect the amount of light passing through a medium and light intensity.
coulomb
-SI unit of charge e = 1.60 X 10^-19C -proton have this charge, proton is positive value, and electron is negative value.
Which likely have a higher conductivity: 1M glucose or 0.25M NaCl, why?
-Sodium chloride solution likely has a higher conductivity because it is a salt and will increase the ion content of water. -glucose does not dissociate in solution, and therefore it has nearly zero impact on its conductivity.
How is sound produced and transmitted?
-Sound is produced by mechanical vibrations. These are usually generated by solid objects like bells or vocal cords, but occasionally can be generated by fluids. -Sound is propagated as longitudinal waves in matter, so it cannot propagate in a vacuum.
ultrasound
-Sound waves with frequencies above the normal human range of hearing -uses high frequency sound waves outside the range of human hearing to compare the relative densities of tissues in the body. -b/c the speed of the wave and travel time is known, the machine can generate a graphical representation of borders and edges within the body by calculating the traversed distance. -ultimately relies on reflection
light dispersion
-Tendency for different wavelengths of light to experience different degrees of refraction in a medium, leading to separation of light into the visible spectrum (a rainbow).
What electrical phenomenon results from the application of the photoelectric effect.
-The accumulation of moving electrons creates a current during the photoelectric effect i.e. solar panels
Assuming the plates are attached by a conducting material, how does a capacitor behave after the voltage source has been removed from a circuit?
-The capacitor discharges, proving a current in the oppositve direction of the initial current
How do the following concepts relate to one another: Venturi effect: Bernoulli's equation: Continuity equation:
-The continuity equation describes the relationship of flow and cross-sectional area in a tube, while bernoulli's equation describes the relationship between height, pressure, and flow. -The venturi effect is the direct relationship between cross-sectional area and pressure, and results from the combined relationships of the Bernoulli and continuity equations.
Electromagnetic Wave Diagram
-The electric field (E) oscillates up and down the page -The magnetic field (B) oscillates into and out of the page. -Both the electric and magnetic field are PERPENDICULAR to the direction of propagation
What is the electric field midway between two negative charges in isolation?
-The electric field would be 0 b/c the two charges are the same -This would cause the fields exerted by each charge at the midpoint to cancel out and thus there would be no electric field
When placed on meter apart from each other, which will experience a greater acceleration: once coulomb of electrons or one coulomb of protons?
-The electrons -Since they both experience the same force, look at F=ma. setting them equal to each other, since the mass of the electron is less, that means to have the same force as the proton, that means that the electron has to have a higher acceleration.
What determines the absorption spectrum of a single atom?
-The energy differences between ground-state electrons and higher-level electron orbits determine the frequencies of light a particular material absorbs, i.e. its absorption spectrum
static pressure
-The force exerted by an enclosed, non-moving fluid when pressure is applied to the fluid -P + pgh -the same as the equation as that for absolute pressure
Normal for reflection
-The normal is the line drawn PERPENDICULAR to the boundary of the medium; all angles in optics are measured from the normal, not the surface of the medium.
How does applying a force at the natural frequency of a system change the system?
-The object will resonate because the force frequency equals the natural (resonant) frequency. -amplitude of the oscillation will increase
Why is the electric potential at points along the perpendicular bisector of a dipole zero?
-The perpendicular bisector of an electric dipole is an equipotential plane that is perpendicular to the axis of the dipole -As such, the equation V=(kqd/r^2)cos(theta) is necessarily equal to 0 b/c cos(90)=0
Diopters
-The unit of power for a lens -focal length is measured in meters -positive for a converging lens and negative for a diverging lens.
Pressure-volume (P-V) curves
-The work done on or by a system undergoing a thermodynamic process can be determined by finding the area under the curve.
How does the work function relate to the energy necessary to emit an electron from a metal?
-The work function describes the minimum amount of energy necessary to emit an electron. Any additional energy from a photon will be converted to excess kinetic energy during the photoelectric effect.
What it the voltage between two points on an equipotential line? Will this voltage cause a charge to move along the line?
-There is NO VOLTAGE between two points between an equipotential line, so there will be no acceleration -however, There is a POTENTIAL DIFFERENCE between difference sets of equipotential lines, which can cause particles to move and accelerate.
What is the maximum distance that two objects can be from one another and still adhere to the zeroth law of thermodynamics?
-There is no theoretical maximum distance. -As long as two objects are in thermal contact and at the same temperature, they are in thermal equilibrium.
Newton's Third Law
-To every action, there is always an opposed but equal reaction.
How designate real and virtual images in mirrors and lenses
-To identify the Real side (R), remember that the real side is where light actually goes after interacting with the lens or mirrors -For mirrors, light is reflected and, therefore, stays in front of the mirror. Hence, for the mirror, the real side is in front of the mirror and the virtual is behind the mirror. -For lenses, the convention is different; because light travels through the lens and travels through the other side, the real side is on the OPPOSITE SIDE OF THE LENS FROM THE ORIGINAL LIGHT SOURCE, and the virtual side is the side where the original light source was located.
During exhalation, how does the total resistance of the encountered air ways change as air leaves the alveoli to escape the nose and mouth?
-Total resistance increases as the air exits the body despite the increase in the diameter. This is because there are fewer airways in parallel with each other.
What phenomena can be detected or treated using ultrasound?
-Ultrasound can be used for prenatal screening or to diagnose gallstones, breast and thyroid masses, and blood clots. -It can be used for needle guidance in a biopsy, for dental cleaning, and for treating deep tissue injury, kidney stones, certain small tumors, cataracts, among many other applications.
What are the boundaries of the visible spectrum? How does the range of the visible spectrum compare to the range of the full electromagnetic spectrum
-Visible light ranges from around 400nm-700nm. -This is comparison from the entire electromagnetic spectrum, which ranges from wavelengths of nearly 0 to 10^9 m.
What is the relationship between weight and density?
-Weight is density times volume and acceleration due to gravity.
What does it mean for a device to provide mechanical advantage
-When a device provide mechanical advantae, it decreases the input force required to generate a particular output -This is generally accomplished at the expense of increase distance over which the force must act
dielectrics in circuit capacitors
-When a dielectric material is placed in a charge capacitor within a circuit, that is, still connect to a voltage source, the charge on the capacitor increases. The voltage remains constant because it is equal to that of the voltage source. -by increasing the amount of charge on the capacitor, the dielectric thus increases of the capacitor by a factor of the dielectric constant. -when a dielectric material is introduced into a circuit capacitor, the increase in capacitance arises from an increase in stored charge (Q) Ex: -capacitors can discharge into wires, causing a current to pass through the wires in much the same way that batteries cause current to move through a circuit.
During which electronic transitions is photon emission most common?
-When electrons transition from a higher-energy state to a lower energy-state, they will experience photon emission.
Photoelectric effect
-When light of a sufficiently high frequency (typically blue to ultraviolet light) is incident on a metal in a vacuum, the metal atoms emit electrons. -albert einsteins 1905 explanation of the photoelectric effect won him the nobel prize. -Electrons liberated from the metal produce a current. -light beams of greater intensity produce larger current in this way. -higher the intensity of the light beam, the greater the number of photons per unit time that fall on an electrode, producing a greater number of electrons per unit time liberated from the metal. -when the lights frequency is above the threshold frequency, the magnitude of the resulting beam is directly proportional to the intensity (and amplitude) of the light beam
What does the zeroth law of thermodynamics state?
-When two objects are both in thermal equilibrium with a third objects, the first two objects must also be in thermal equilibrium. -no heat flows between the objects.
Draw the field lines for the electric field generated by an alpha particle:
-Would have a 2+ charge on the middle atoms, with the field lines pointing outwards (repulsive)
resistors
-a device having a designed resistance to the passage of an electric current.
hydraulic systems
-a device that transmits an applied force through a liquid to move something else by means of pressure
Chromatic aberration
-a dispersive effect within a spherical lens -depending on the thickness and curvature of the lens, there may be significant splitting of white light, which results in a rainbow halo around images
Radioactive decay
-a naturally occurring spontaneous decay of certain nuclei accompanied by the emission of specific particles. Know 3 types of problems for the MCAT: 1. the integer arithmeic of particle and isotope species 2. radioactive half-life problems 3. the use of exponential decay curves and decay constants
electron
-a negatively charged subatomic particle
Total internal reflection
-a phenomenon in which all the light incident on a boundary is reflected into the original material, results with any angler of incidence greater than the critical angle.
isothermal process
-a process that occurs at constant temperature -since T is constant (deltaT=0), then internal energy (DeltaU) = 0 -1st law reduces to Q=W
dipole moment
-a property of a molecule whose charge distribution can be represented by a center of positive charge and a center of negative charge p=qd p=dipole moment q=charge d=distance between charges
reversible reaction
-a reaction in which the conversion of reactants into products and the conversion of products into reactants occur simultaneously -freezing and melting of water in real life are therefore irreversible processes in PHYSICS while still being chemically reversible.
electric fields
-a region around a charged particle or object within which a force would be exerted on other charged particles or objects.
magnetic field
-a region around a magnetic material or a moving electric charge within which the force of magnetism acts. -may be set up by the movement of individual charges, such as an electron moving through space; by the mass movement of charge in the form of a current through a conductive material, such as a copper wire; or by permanent magnets -SI unit: the tesla (T) -1 T = 1 (N*s)/(m*C) - 1 T = 10^4 gauss
Energy
-a systems ability to do work (make things happen). Ex: -mechanical energy can cause objects to move or accelerate. -ice cube sitting in the kitchen counter at room temp absorbs thermal energy through heat transfer.
centripetal acceleration
-acceleration of an object toward the center of a curved or circular path.
open boundaries
-allow maximal oscillation - places of antinodes - ex: open end of a pipe or free end of a string
weak nuclear force
-an attractive force that acts only over a short range -contributes to the stability of the nucleus, one millionth as strong as the strong nuclear force.
Work equation
-angle is between the applied force vector and the displacement vector
To which side of a hydraulic lift would the operator usually apply a force: -side with larger area, or smaller area, why?
-applies force to side with a smaller cross-sectional area. -since pressure is the same on both sides of the lift, a smaller force can be applied on the smaller surface area to generate the desired pressure
secondary batteries
-are rechargeable -When recharging, an external voltage is applied in such a way to drive current towards the positive end of the second battery In electrochemistry: -cell acts as a galvanic (voltaic) cell when it discharges -acts as an electrolytic cell when it recharges
Venturi effect
-as the area decreases from point 1 to point 2, the linear speed increases -as the dynamic pressure increases, the absolute pressure decreases at point 2 -with a lower absolute pressure, the column of fluid sticking up from the Venturi tube is lower at point 2
As the effort decreases in a pulley system, what happens to the effort distance to maintain the same work output?
-as the effort (required force) decreases in a pulley system, the effort distance increases to generate the same amount of work.
Venturi flow meter
-as the tube narrows, the linear speed increases at point 2. -Thus, the pressure exerted on the wall decreases, causing the column above the tube to have a lower height then at point 2
diamagnetic
-atoms with no unpaired electrons and that have no magnetic field, -slightly repelled by a magnet, so are weakly antimagnetic Ex: -wood, plastics, water, glass, skin
adhesion
-attractive force that a molecule of a liquid feels toward the molecules of some other substance Ex: -adhesive forces cause water molecules to form droplets on the windshield of a car even though gravity is pulling them downward.
cohesion
-attractive force that a molecule of liquid feels toward other molecules of the same liquid.
electric field on the perpendicular bisector of a dipole
-b/c angle between this equipotential line and the dipole axis is 90 (cos90=0), the electric potential at any point along this plane is 0. -electric field vectors at the points along the perpendicular bisector will point in the direction opposite to p.
How many half-lives are necessary for the complete decay of a radioactive sample?
-b/c the amount is cut in half after each half life, the portion remaining will never quite reach zero. -This is mostly a theoretical consideration; "all" of a sample is said to have decayed after 7 to 8 half-lives.
Poiseuille's law
-calculates rate of flow through a pipe of confined space (laminar flow) Q= (πr^4 ∆P)/8ηL η: viscosity of the fluid Q: flow rate (volume flowing per time) ΔP: pressure gradient r: radius of tube L: length of tube
process functions
-describe path taken to get from one state to another -work and heat
Ray diagrams are used to
-determination for characteristics of the the type of image that will be produced some distance from the mirror. Real vs virtual Inverted vs upright magnified vs reduced
conduction
-direct transfer of energy from molecule to molecule through molecular collisions -requires direct contact between the objects -particles of hotter matter transfer some of their kinetic energy between the particles of the cooler material through collisions of particles. -metals are best conductors, while gases are the poorest. Ex: -your hands touching a hot stove
solids
-do not flow and are rigid enough to retain a shape independent of their retainers
closed boundaries
-don't allow oscillation -places of nodes -ex: closed end of a pipe or secured ends of a string
ohmmeters
-don't require a circuit to be active -have their own battery of known voltage and then function as ammeters through another point in the circuit -can calculate resistance by knowing the ommeter's voltage and the current created through another point in the circuit.
permittivity of free space
-e0 (capacitance) -8.85 x 10^-12 C^2/N*m^2
gravitational potential energy
-energy that depends on an objects position with respect to some level identified as the datum ("ground" or zero potential energy position)
Coulombs law and gravitational force
-equations look very similar. -in electrostatics, force is proportional to the charge magnitudes, while in gravitational, force is proportional to the masses of the objects. -both equations, force of the magnitude is inversely proportional to the distance between them, so as distance between objects increase, the forces between the objects decreases.
Rotational equilibrium
-exists when the vector sum of all the torques acting on an object is zero
What causes fluorescence?
-fluorescence is a special stepwise photon emission in which an excited electron returns to its ground state through one of more intermediate excited states. -Each energy transition releases a photon of light. With smaller energy transitions than the initial energy absorbed, these materials can release photons of light in the visible range.
kinetic friction
-frictional force that acts opposite of motion of the object that exists between a sliding object and the surface over which the object slides.
Ferromagnetic materials
-have unpaired electrons and permanent atomic magnetic dipoles that are normally oriented randomly so that the material has no net magnetic dipole -unlike paramagnetic materials, ferromagnetic materials will become strongly magnetized when exposed to a magnetic field and under certain conditions Ex: -iron, nickel, and cobalt
block suspended by two ropes
-if block is in translational equilibrium, the tension in each rope is equal to half the weight of the block
Determining if a force is conservative
-if the change in energy around any round-trip path is zero, or if the change in energy is equal despite taking any path between two points, then the force is conservative
How does the electric potential energy change between two particles as the distance between them increases?
-if the particles have the same charge, the electric potential energy would DECREASE as DISTANCE DECREASES. -if the particles have opposite charges, than the electric potential energy INCREASES as distnance INCREASES.
how to determine the direction of an electric field vector
-if the source charge is positive, then the test charge would experience a repulsive force and would accelerate away from the positive source charge. -if source charge is negative, then the test charge would experience an attractive force and would accelerate TOWARDS negative source charge
field lines
-imaginary lines that represent how a positive test charge would move in the presence of the source charge -drawn in the direction of the actual electric field vectors and also indicate the relative strength of the electric field at a given point in the space of the field -when drawn, look like metal spokes of a bicycle wheel
dielectric material
-insulator (air, glass, plastic) -introduced b/w the plates of a capacitor - increases capacitance by a factor called dielectric constant (k)
Cross-sectional area of a resistor
-inverse proportional resistance and the cross-sectional area of the resistor. -this is b/c the increase in area increases the number of pathways through the resistor. -wider the resistance, the more current that can flow, analogous to a river.
static charge buildup/static electricity
-is an imbalance of electric charges within or on the surface of a material. The charge remains until it is able to move away by means of an electric current or electrical discharge.
Voltmeter
-measure the voltage drop across two points in a circuit -require a circuit to be active -use the magnetic properties of current-carrying wire -wired in parallel -ideal voltmeter has infinite resistance
Sound level
-measured in decibels (dB) I: intensity of the sound wave I0 : threshold of hearing (1 x 10^-12 W/m^2)
equipotential line
-line on which the potential at every point is the same. -the potential difference between any two points on an equipotential line is zero. -look line concentric circles surrounding a source charge, spheres in 3-D. -work will be done in moving a test charge (q) from one line to another, but the work on depends on the POTENTIAL DIFFERENCE between them, not the path taken between them. -Analogous to the displacement of an object horizontally on a level surface, since objects height hasn't changed, its U(grav) hasn't changed.
Backwards (convex) of meniscus
-liquid level is higher in the middle than at the edges -occurs when cohesive forces are greater than adhesive forces mercury forms convex meniscus
Multiplying vectors by scalars
-magnitude of vector will change -direction of vector will be either parallel or antiparallel to its original direction, depending on if the scalar is positive or negative.
density
-mass/volume -scalar quantity SI Units: -Kg/m^3 -g/mL -g/cm^3
conductor
-material that allows heat and electricity to pass through it. -when a conductor is given a charge, the charges will distribute approximately evenly upon the surface of the conductor -most metals are conductors, also ionic solutions (electrolyte) are also effective conductors
insulator
-material that does not allow heat or electrons to move through it easily. -doesn't easily distribute a charge over its surface and will not transfer that charge to another neutral object as well, especially another insulator. -most nonmetals are insulators
amplitude
-maximum magnitude of displacement in a wave
dielectric constant (k)
-measure of insulating ability of a material (vacuum has dielectric constant of 1) -A dielectric material never decreases the capacitance so k can never be less than 1 (C' = kC) -When a dielectric material is placed in an isolated, charged capacitor (disconnected from any circuit) the voltage across the capacitor decreases (by lowering the voltage, the dielectric increases the capacitance) -When a dielectric material is placed in a charged capacitor within a circuit (connected to voltage source), the charge of the capacitor increases * voltage remains constant (equal to the voltage source) *by increasing the amount of charge stored on the capacitor the dielectric increases capacitance
linear speed
-measure of the linear displacement of fluid particles in a given amount of time.
Conductance
-measure of the permeability of a charged particle; inverse of resistance -measured in siemens (S), sometimes given as siemens per meter (S/m) for conductivity
entropy
-measure of the spontaneous dispersal of energy at a specific temperature: -how much energy is spread out, or how widely spread out energy becomes in a process. -SI Unit: J/(mol*K)
Ammeters
-measure the current at some point within a circuit. -inserted in series where the current is being measured and use the magnetic properties of a current carrying wire to cause a visible needle movement or a calibrated display of the current. -ideal ammeters have zero resistance and no voltage drop across them
Angular frequency:
-measured in radians/sec w=2πf or w= 2π/T
fluid dynamics
-study of fluids in motion
nonconservative forces
-path dependent -cause dissipation of mechanical energy from a system -total energy conserved, but some mechanical energy lost as thermal/chemical energy ex) friction, air resistance, viscous drag (resistance force created by fluid viscosity)
conservative forces
-path independent and do not dissipate the mechanical energy of a system. -Two most common on MCAT are gravitational and electrostatic
thermal expansion
-physical properties of matter change when the matter is heated or cooled. -length, volume, solubility, and conductivity of the object change as a function of temperature. -integral part to the development of thermometers.
nodes
-points in the wave that remain at rest -places where amplitude is zero
antinodes
-points midway between the nodes fluctuate with maximum amplitude.
System
-portion of the universe that we are interested in observing or manipulating
proton
-positive charge -found in nucleus
reynolds number
-predicts whether flow is laminar or turbulent -equals average flow speed X tube diameter X density/viscosity -depends on factor such as the size, shape, and surface roughness of any objects within the fluid.
dynamic pressure
-pressure associated with movement of fluid -1/2pv^2 -kinetic energy of the fluid divided by volume
Fission
-process by which a large nucleus is split into smaller nuclei. Spontaneous fission rarely occurs. -through absorption of a low-energy neutron, fission can be induced in certain nuclei. -some fission reactions release more neutrons because these other neutrons will cause a chain reaction in which other nearby atoms can undergo fission, in turn releases more neutrons, continuing the chain reaction.
Adiabatic process
-process in which no heat is transferred to or from the system by its surroundings. (Q=O) -1st law reduces to DeltaU=-W
natural process
-process that occurs naturally -irreversible ex: -when hot and cold objects are put in thermal contact, we expect heat to transfer from hot to cold object. this is irreversible, since we wouldn't expect if the hot object became hotter and the cold object became colder
At what angle of launch is a projectile going to have the greatest horizontal and vertical displacement?
-product of sine and cosine is maximized when angle is 45 degrees. -horizontal displacement relies on both measures, so maximum horizontal displacement will also be achieved at this angle. -vertical displacement will always be zero as the object returns to the starting position.
temperature
-proportional to the average kinetic energy of the particles that make up the substance. -at macroscopic level, it is the difference in temperature between two objects that determines the direction of heat flow.
Vectors
-quantities that have both a magnitude and a direction Ex: -displacement, velocity, acceleration, and force
beta decay
-radioactive decay of an atomic nucleus that is accompanied by the emission of a beta particle
circular polarization
-rarely seen natural phenomen that results from the interaction of light with certain pigments or highly specialized filters. -circularly polarized light has a uniform amplitde but a continuously changing direction, which causes a helical orientation in the propagating wave -The helix has average electrical field vectors and magnetic field vectors that lie perpendicular to one another, like waves, with maxima that fall on the outer border of the helix
power
-rate at which energy is transferred from one system to another
Mechanical Advantage (MA)
-ratio of magnitudes of the force exerted on an object by a simple machine (Fout) to the force actually applied on the simple machine (Fin). -b/c its a ratio between forces, its dimensionless.
electric potential
-ratio of the magnitude of a charge's electric potential energy to the magnitude of the charge itself 2 ways: -V=U/q -V=kQ/r U=electric potential energy q= charge V= electric potential in volts 1V = 1 J/C
Reflection
-rebounding of incident light waves at the boundary of a medium. -Light waves that are reflected are not absorbed into the second medium,; rather, they bounce off the boundary and travel back through the first medium.
absolute zero
-reference point for all three major temperature scales. -theoretical temperature at which there is no thermal energy.
visible region
-region of the electromagnetic spectrum that is characteristic of absorbances of compounds with eight or more double bonds (e.g. B-carotene has 11 conjugated double bonds) 400 (violet) -700nm (red) 700-400 = ROYGBIV
streamlines
-representations of molecular movements -indicate pathways followed by tiny fluid particles as they move
internal resistance
-resistance inside the source of electrical energy (battery)- loss of PD per unit current in the source when current passes through it -if cell is not actually not driving any current, such as when a switch is open, then the internal resistance is zero, and the voltage of the cell is equal to its emf. -when the current is not zero and the internal resistance is not negligible, then voltage will be less than emf.
Length in a resistor
-resistance of a resistor is directly proportional to its length -a longer resistor means that electrons will have to travel a greater distance through a resistant material.
surroundings
-rest of the universe outside the system, that is interacting with the system that we are studying.
Resistors in series
-same current travels through all the resistors (I1 = I2 = I3) - voltages add -resistances are additive (Requivalent = R1 + R2 + ...) -As the e- flow through each resistor, there is a voltage drop in each resistor. -voltage drops are additive V = V1 + V2 + ... -Equivalent resistance is the sum of individual resistances (increases as more resistors are added in series)
metallic conductivity
-seen in solid metals and molten forms of some salts -metal atoms can easily lose one or more of their outer electrons, which are then free to move around in the larger collection of metal atoms
electrolytic conductivity
-seen in solutions -depends on the strength of a solution -DI water could be considered an insulator, wile sea water and OJ are excellent conductors -conductivity is measured by placing the solution as a resistor in a circuit and measuring changes in voltage across the solution -can be used to determine ionic concentrations in solutions such as blood.
noise
-sounds that we do not find particularly musical
pitot tubes
-specialized measurement devices that determine the speed of fluid flow by determining the difference between the static and dynamic pressure of the fluid at given points along a tube
focal length
-the distance from the center of a lens to the focal point -For all spherical mirrors, f=r/2, where r = radius of curvature -radius of curvature is the distance between C (center of curvature) and the mirror.
third law of thermodynamics
-the entropy of a perfectly organized crystal at absolute zero is zero. -no negative temperatures on the kelvin scale because it starts from absolute zero.
atmospheric pressure
-the pressure exerted by atoms and molecules in the atmosphere surrounding Earth, resulting from collisions of these particles with objects -changes according to altitude
Electron Capture
-the process in which an inner orbital electron is captured by the nucleus of the atom that contains the electron -reverse of beta decay
Ground (electrostatics)
-the reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the earth. Electrical circuits may be connected to ground (earth) for several reasons
critical speed
-the speed above which flow of a fluid will be turbulent
Hydrostatics
-the study of fluids at rest and the forces and pressures associated with standing fluids.
First, third, and fifth harmonics of a closed pipe
-there are no even harmonics for a closed pipe
state functions
-thermodynamic properties that are a function of only the current equilibrium state of the system -INDEPENDENT of the path take to get to a particular equilibrium state Includes: pressure (P) density (rho) temperature (T) volume (V) enthalpy (H) internal energy (U) Gibbs Freee energy (G) Entropy (S)
absolute (hydrostatic) pressure
-total pressure that is exerted on an object that is submerged in a fluid P = P0 + ρgy P0: incident or ambient pressure (pressure at the surface) y: depth of the object g: acceleration due to gravity
radiation
-transfer of energy by electromagnetic waves -unlike conduction and convection, radiation can transfer energy through a vacuum. -method by which sun is able to warm the earth.
convection
-transfer of heat by the physical motion of a fluid over a material -b/c convection involves flow, only liquids and gases can transfer heat by this means. -if the fluid has a higher temperature, it will transfer energy to the material Ex: -running a cold water bath used to rapidly cool a reaction
heat
-transfer of thermal energy from a hotter object with higher temperature (energy) to a colder object with lower temperature (energy) -results because of a difference in temperature -SI unit is a joule (J) 1 Cal = 10^3 cal = 4184 J = 3.97 BTU
Electromagnetic waves
-transverse waves consisting of changing electric fields and changing magnetic fields -The electric field (E) oscillates up and down the page -The magnetic field (B) oscillates into and out of the page.
What are the units for work? how are work and energy different?
-unit of work is the joule, which is also the unit for energy -Work and energy are related concepts. By performing work, the energy of a system is changed. Work, along with heat, is a form of energy transfer
X-ray diffraction patterns
-uses the bending of light rays to create a model of molecules -often combined with protein crystallography during protein analysis -dark and light fringes do not take on a linear appear, but rather, a complex two dimensional image
electromotive force (emf)
-voltage when no charge is moving b/w the 2 terminals of a cell that are at different potential values -"Pressure to move" exerted by the cell on the electrons -units of voltage, not newtons, because it isn't actually a force, 1V = J/C V= (emf) -i (R internal)
wave propagation
-ways in which waves travel -in transverse waves, particles oscillate perpendicular to the direction of propagation -in longitudinal waves, particles oscillate parallel to the direction of propagation
Dielectrics in isolated capacitors
-when a dielectric material is placed in an isolated, charged capacitor, -that is, disconnected from any circuit-, the voltage across the capacitor decreases -this is the result of the dielectric material shielding the opposite charge from each other, lowering hte voltage across a charged capacitor, -increase in capacitance arises from a decrease in voltage
traveling wave
-when a string fixed at one end is moved up and down, a wave forms and travels toward the fixed end -When the wave reaches the fixed boundary, it is reflected and inverted -If the free end of the string is continuously moved up and down, there will be 2 waves: the original wave moving down the string toward the fixed end and the reflected wave moving away from the fixed end (interfere w/ each other)
Rectilinear propagation
-when light travels through a homogenous medium, it travels in a straight line.
thermal equilibrium
-when no net heat flows between two objects in thermal contact, then their temperatures but also be equal.
Laminar flow around an object sinking in a fluid
-when the gravitational force is larger than the buoyant force, an object will sink. -Laminar flow is characterized by smooth flow lines around the object.
principle of superposition
-when waves interact with each other, the displacement of the resultant wave at any point is the sum of the displacements of the two interacting waves
Reflection in a plane mirror
1) The light rays are coming from an object (chess) in front of a plane mirror. Thousands of rays are coming off, but for simplicity, only 2 rays are drawn 2)After reflection, some of the rays enter the eye. To one's eye, the ray seem to come from a position behind the mirror, so that where one sees the image of the chess. *The dotted lines show the point where the two of the reflected rays appear from and the dotted lines are NOT rays. 3) The image on the mirror looks exactly the same as the object apart from the image is laterally inverted (back to front).
Wave Types
1) Transverse Waves 2) Longitudinal Waves
Applying the Right-Hand rule
1. point your thumb in direction of vector A 2. extend your fingers in the direction of vector B. You may need to rotate your wrist to get the correct configuration of thumb and fingers 3. Your palm establishes the plane between the two vectors. The direction your palm points is the direction of the resultant C, (or you can extend your middle finger outwards in the direction of your palm)
Capacitors in series
1/C=1/C₁+1/C₂+... -reciprocal capacitances are added -equivalent capacitance decreases as more capacitors are added in series -same current -voltages add
lensmaker's equation
1/f = (n-1)(1/r1 - 1/r2) -used for lenses with nonneglibable thickness. n=index of refraction of lens material r1= radius of curvature of first lens surface r2=radius of curvature of the second lens surface
Key variables in geometrical optics
1/f = 1/o + 1/i = 2/r f = focal length o = object distance from mirror i = image distance from mirror
What are the two mathematical relationships between image distance and object distance?
1/f = 1/o + 1/i = 2/r m=-i/o
Thin Spherical lenses
1/f = 1/o + 1/i= 2/r m=-i/o
Focal length of multiple lens system
1/f= 1/f1+1/f2+1/f3.....
What are three ways to calculate work done on or by a system?
1: W=Fdcos(theta) -dot product of forace and displacement vector 2: W=PdeltaV (area under a P-V curve) 3: Wnet=DeltaK (work-energy theorem)
What are the two methods for calculating the magnitude of the electric field at a particular point in space
1st: -place a test charge q at some point, and measure the force exerted on the test charge, and define the electric field at the point as the ration between the two (Fe/q) 2nd: -know the magnitude of the source charge and the distance between the source charge and point in space at which we want to measure the electric field. (kQ/r^2)
partially constructive interference
2 waves not quite perfectly in phase displacement = sum of displacements of 2 interfering waves
partially destructive interference
2 waves not quite perfectly out of phase displacement = sum of displacements of 2 interfering waves
alpha decay equation
222/88 Ra ---> 4/2 He + 218/86 R
speed of light
3.00 x 10^8 m/s
alpha particle
A cluster of 2 protons and 2 neutrons emitted from a nucleus in one type of radioactivity
hyperopia
A condition in which visual images come to a focus behind the retina of the eye and vision is better for distant than for near objects -- called also farsightedness. corrected by bifocals
continuity equation
A1V1=A2V2
Average Acceleration Equation
A=Delta v/ Delta t
atomic absorption
Absorption of radiation by atoms. The radiation is supplied by an external source. Atomic absorption is the atomic analog of molecular absorption spectroscopy.
Complete the following chart: Nuclear reaction, and what it emits, change in Z and change in A For alpha decay, beta-negative and positive decay, gamma decay, and electron capture
Alpha Decay: -emits an alpha particle (4a2, or He (4 2) -Loss of 2 in Z -Loss of 4 in A Beta-negative decay: -Electron and antineutrinto (e^-1) -Plus of 1 in Z -No change in A Beta-Positive Decay: -Positron and neutrino (e+, B+) -Loss of 1 in Z -No change in A Gamma Decay: -Gamma Ray -No change in Z -No Change in A -Electron Capture: -Nothing, its just absorbing an electron from the inner shell) -Loss of 1 in Z -No change in A
What do each of the following types of meters measure? Where are they placed in circuits? What are their ideal resistances?
Ammeter: -measures current -placement is in series with point of interest -ideal resistance is 0 Voltmeter: -measures potential difference (voltage) -Place parallel with circuit element of interest -ideal resistance is infinity Ohmmeter: -measures resistance -placement is two points in series with circuit element of interest -ideal resistance is 0
heat of fusion
Amount of energy required to change a substance from the solid phase to the liquid phase.
To which properties of a sound wave do amplitude and frequency correspond?
Amplitude: -related to its sound level (volume) Frequency: -related to its pitch.
Doppler effect
An observed change in the frequency of a wave when the source or observer is moving (+/-) for towards (-/+) for away
forced oscillation
An oscillation that occurs & stays , Where an object is forced to oscillate by an external force.
order units from smallest to largest: Centimeter Angstrom Inch Mile Foot
Angstrom<centimeter<inch<foot<mile
magnetic field from a loop of wire
B = uI/2r b=magnitude of magnetic field @ center of the loop u= permeability of free space (4pi X 10^-7 Tm/A) r= radius of loop
Sound level equation
B=sound level measured in decibals I= intensity of the sound wave Io=threshold of hearing (1 X 10^-12 W/m^2)
magnetic field from a straight wire equation
B=uI/2pir B=magnetic field @ distance r from the wire u= permeability of free space (4pi X 10^-7 Tm/A) I- current (A) r= perpendicular distance
Magnetic field from a straight wire
B=uI/2pir B=magnetic field @ distance r from the wire u= permeability of free space (4pi X 10^-7 Tm/A) I- current (A) r=perpendicular distance -inverse relationship between magnitude of magnetic field and the distance from the current. -straight wires create magnetic fields in the shape of concentric rings
Change in sound level
Bf = Bi + 10log(If/Ii)
capacitance due to a dielectric material
C'=kC -C'=new capacitance -k= dielectric constant -C= original capacitance
Categorize the following materials as either conductors or insulators: blood hair copper glass iron sulfuric acid distilled water
Conductors: -Blood (has iron) -Copper -Iron -sulfuric acid Insulators -hair -glass -distilled water
fahrenheit to celsius
C=5/9(F-32)
Capacitors in parallel
C=C₁+C₂+C₃+... -capacitances add to yield equivalent capacitance -equivalent capacitance increases as more capacitors are added in parallel - same voltage across each parallel capacitor *Cequiv = C1 + C2 + ...
Capacitance equation
C=Q/V C= capacitance in farad (1 F = 1 C/V) Q= Charge (coulombs) V= voltage applied across the plates of a capacitor
Capacitance based on parallel plate geometry
C=e0(A/d) -capacitance is dependent upon the geometry of the two conduction surfaces -Eo=permitting of free space (8.85 X 10^-12) -A= area of overlap of the two plates -d=separation of charges between the two plates
How does a dielectric material impact: capacitance voltage charge
Capacitance: -always increases Voltage: -If the capacitor is isolated, its voltage will decrease when a dielectric material is introduced; if its in a circuit, its voltage is constant because it is dictated by the voltage source Charge: -If a capacitor is isolated, the stored charge will remain constant because there is no additional source of charge; if its in a circuit, the stored charge will increase.
contrast cohesion and adhesion
Cohesion: -attractive force experienced by molecules of a fluid for one another (like materials) Adhesion: -attractive force experience by molecules of a fluid for a DIFFERENT MATERIAL (usually solid).
What are the types of spherical mirrors?
Concave and convex
what are some examples of: conservative and non-conservative forces
Conservative: -gravity, electrostatic forces, elastic forces (approx.) Non-conservative: -Friction, air resistance, viscous drag
Does the path taken matter with: conservative and non-conservative forces:
Conservative: -no non-conservative: -yes, more energy is dissipated w/ a longer path
What happens to total mechanical energy w/: conservative and non-conservative forces
Conservative: -stays the same non-conservative: -decreases (energy is dissipated:
Define the terms and provide their SI units Current Voltage Electromotive force (emf) Conductivity
Current: -Flow of positive charge through a conductive material overtime and is given in amperes (1A=1C/s) Voltage: -potential difference between two points and is given in volts. (1V=1J/s) Electromotive force (emf): -potential difference of the voltage source for a circuit, usually a battery, and is given in volts. Conductivity: -reciprocal of resistance and is a measure of permissiveness to current flow; measured in siemens (S).
Define the following terms: Dynamic pressure static pressure pitot tube viscosity laminar flow turbulence
Dynamic pressure: -pressure associated with flow -represented by 1/2pv^2. Static pressure: -pressure associated with position; -static pressure is sacrificed for dynamic pressure during flow Pitot tube: -device that measures static pressure during flow to calculate speed Viscosity: -measure of the resistance of a liquid to flow. Laminar flow: -flow in which there are no eddies and in which streamlines roughly parallel to one another Turbulence: -presence of backflow or current eddies
Change in entropy
DeltaS=Qrev/T DeltaS=change in entropy Qrev=heat that is gained or lost in reversible process T=temp in kelvins units of S: J/(mol*K)
voltage equation
DeltaV= Vb-Va = Wab/q -Va and Vb= electric potentials at points a and b -Wab = work needed to move a test charge q through an electric field from point a to point b
Thermal expansion equation (liquid)
DeltaV=(Beta)(Vi)(DeltaT) -DeltaV= change in volume -Beta= coefficient of volumetric expansion (Beta=3alpha) -Vi=original volume -DeltaT=Change in temperature
How does double-slit diffraction and interference differ from single-slit diffraction?
Double-slit: -The image formed during double slit diffraction contains fringes because light rays constructively and destructively interfere Single slit: -forms an image of a wide band of light, spread out from its original beam
total mechanical energy
E=U+K
Uniform Electric Field of Capacitor
E=Vd=Pt The electric field between plates of a parallel plate capacitor. The direction is from the positive to the negative plate.
Energy of a photon
E=hf E=energy of the photon of light h= planck's constant (6.626 X 10^-34 J*S) f=frequency of light can also find wavelength of photon after this using c=f(lamda)
Mass defect and energy
E=mc^2 m= mass defect = mass of protons and neutrons individually- mass of the element c=speed of light
efficiency equation
Efficiency= Useful energy output/total energy input -Measured in %
What is the difference between electric potential and voltage?
Electric potential: -ratio of a charge's electric potential energy to the magnitude of the charge itsle Voltage (potential difference): -measure of the change in electric potential between two points, which provides an indication of the tendency toward movement in one direction or the other.
radio waves
Electromagnetic waves with the longest wavelengths and lowest frequencies
Gamma rays
Electromagnetic waves with the shortest wavelengths and highest frequencies
How do distance and charge relate to electrostatic force and electric field?
Electrostatic force: -directly related to each charge -related to the distance by an inverse square relationship Electric field: -unrelated to test charge -related to distance by inverse square
first law of thermodynamics (law of conservation of energy)
Energy can be transferred and transformed, but it cannot be created or destroyed.
Atomic emission
Energy from some external process raises atoms into a spectroscopically excited state. The excited state atoms themselves then act as a source, re-emitting radiation (a photon) as they decay back to the ground state.
Define terms: Equipotential lines Electric dipole
Equipotential lines: -set of points within space at which the potential difference between any two points is zero. -best visualized as concentric spheres surrounding a source charge Electric dipole: -the separation of charge within a molecule such that there is a permanent or temporary region of equal and opposite charge at a particular distance.
Magnetic force on a moving point charge
F = qvBsinθ F= magnetic force q= charge v= magnitude of velocity B = magnitude of magnetic field theta =smallest angle between the velocity vector (v) and the magnetic field vector (B)
Pascal's Principle equation
F1/A1=F2/A2
gravitational force between two objects
F=Gm1m2/r^2 G: 6.672*10^-11 r: distance between two objects G: 6.67 X 10^-11 N * m^2/kg^2
Newton's Second Law
F=ma -An object of mass m will accelerate when the vector sum of the forces results in some nonzero resultant force vector -no acceleration when the vector sum of forces results in a cancellation of those forces.
weight of a volume of fluid
F=ρVg ρ= density kg/m^3 V=Volume, L
True/False: Small changes in structure only minimally impact light absorption and emission patters
False -Small changes, such as protonation and deprotonation, change in oxidation state and bond order, and others may cause dramatic changes in light absorption in a material.
true/false sound waves are a prime example of transverse waves
False Sound waves are the most common example of longitudinal waves on the MCAT
True/False: The sum of the voltage sources in a circuit is equal to the sum of the voltage drops in that circuit.
False: -While the voltage sources and voltage drops are equal in any closed loop, this is not necessarily true for the entire circuit. -For example, a 9 V battery that powers 10 light bulbs in parallel has a 9 V voltage source and a 9 V drop across each light bulb, a total of 90 V of drop across all of the light bulbs combined.
True/False: Light waves are longitudinal because the direction of propagation is perpendicular to the direction of oscillation.
False: Light waves are TRANSVERSE because the direction of propagation is perpendicular to the direction of oscillation
True/False: A voltmeter and an ammeter should not be placed in the same circuit
False: Voltmeters and ammeters are designed to have minimum impact on a circuit; thus, they can be used together.
True/False: The kelvin scale is the most accurate measurement method for temperature because it is based on absolute zero.
False: -Accuracy is related to an instrument, rather than a scale. -Kelvin uses the same scale as Celsius, so there is no practical differences in terms of accuracy.
Magnetic force on a current carrying wire
Fb=ILBsin(theta) I=current L=length of wire B=Magnetic field theta= angle between L and B
centripetal force equation
Fc = mv^2/r
pressure
Force per unit area. P=F/A SI units: -N/M^2 1Pa = 1N/m^2 1.013 X 10^5 Pa = 760mmHg = 760 torr = 1 atm
Order ALL the electromagnetic waves from Highest to lowest energy: What also follows the same trend on the electromagnetic spectrum:
Gamma rays X rays UV Visible Visible Microwaves Radio Waves (AM/FM) Long Radio Waves Increasing Frequency follows the same trend as increasing energy, opposite of wavelength trend.
Lowest to highest wavelength on the electromagnetic spectrum
Gamma rays, x-rays, UV, Visible light, IR waves, Microwaves, FM/AM Radio Waves, Long Radio Waves
P-V graphs
Gas expansion and compression processes can be represented in graphical form with volume on the x-axis and pressure on the y-axis
What effect would increasing the following have on flow rate: radius of the tube pressure gradient viscosity length of the tube
Increase when: -either the radius of the tube or the pressure gradient increases. Decrease when: -increasing viscosity or length of the tube
A negatively charged insulator and conductor
Insulators will not distribute charge over their surface; conductors will.
Intensity equation
Intensity = Power / Area
turbulent flow
Irregular flow with random variations in pressure.
celsius to kelvin
K=C+273
attenuation
Loss of power in a signal as it travels from the sending device to the receiving device
Describe the bending of light when moving to medium with high to low refractive index and a low to high refractive index.
Low to high: -light will bend TOWARDS the normal High to low: -Light will bend AWAY from the normal -if the incident angle is larger than the critical angle, total internal reflection will occur.
How is entropy different/similar on a macroscopic level and in statistical terms?
Macroscopic level: -entropy can be thought of as the tendency towards disorder. Statistically: -entropy is the measure of the spontaneous dispersal of energy at a specific temperature, increasing the number of available microstates for a given molecule.
conduction pathways
Number of pathways through a resistor
uniform circular motion
Objects moving in a circle with constant speed (acceleration results in a change of direction)
shear (tangential) forces
Only solids can withstand these; fluids can impose strong perpendicular force.
Parent nucleus
Original nucleus that transforms as a result of radioactive decay
Power of multiple lens system
P = P1 + P2 + P3 + ... + Pn
Bernoulli's equation
P1 +1/2 ρv_1^2+ρgh_1= P_2+1/2 ρv_2^2+ρgh_2 P : absolute pressure of the fluid v: linear speed h: height of the fluid
Electric power equation
P=IV=I^2R=V^2/R
How does power relate to current, voltage, and resistance?
P=IV=I^2R=V^2/R
gauge pressure equation
Pg = P - Patm = (P0 + pgz) - Patm
Contrast plane and circularly polarized light:
Plane polarized light: -contains light waves with PARALLEL electric field vectors Circularly polarized light: -Selects for a given amplitude and has a continuously rotating electric field direction
Decay Constant
Probability of decay of a nucleus per unit time
damping
Process where the energy of an oscillating system decreases with amplitude by a dissipative force acting in the opposite direction.
unnatural process
Processes that are generally reversible, Ex : Hot object in contact with cold object becomes hotter while cold object gets colder
Energy of an electromagnetic wave
Proportional to the frequency. Therefore, waves with the highest frequency have the highest energy
Resistance of a resistor
R=(Rho)(length)/A rho=resistivity L=length of the resistor A=cross sectional area
What four quantities determine the resistance of a resistor?
Resistivity, length, cross-sectional area, and temperature
How to determine the direction of field vectors
Right hand rule: -Point your thumb in the direction of the current and wrap your fingers AROUND the current-carrying wire. -your fingers then mimic the circular field lines, curling around the wire.
joule
SI unit of energy -(kgm^2)/(s^2)
How does adding or removing a capacitor change the total capacitance of a circuit with capacitors in series? in parallel?
Series: -Adding a capacitor in series decreases the total capacitance of a circuit, removing one increases the total capacitance Parallel: -Adding a capacitor increases the capacitance, while removing one decreases it.
How does the diffraction pattern for a single slit differ from a slit with a thin lens?
Single slit: -Diffraction through a single slit does not create characteristic fringes when projected on a screen, although the light does spread out Slit with a thin lens: -when a lens in introduced, the additional refraction of light causes constructive and destructive interference, creating fringes.
infrasonic waves
Sound waves with frequencies below 20 Hz.
what is the difference between a state function and a process function?
State functions: -variable independent from the path take to achieve a particular equilibrium and are properties of a given system at equilibrium; they may be dependent to one another Process Functions: -define the path (or how the system got to its state) through variables such a heat (Q) or work (W).
Finding the resultant (R) of V1 + V2 + V3
Steps: 1. resolve vector into x and y components 2. Add components to get Rx and Ry 3. find magnitude by using pythagorean theorem 4. find the resultant direction by using inverse tangent to find the angle of the final vector
Define the terms: Strong nuclear force Mass Defect Binding Energy
Strong Nuclear Force: -one of the four fundamental forces of nature and provides the adhesive force between the nucleons (protons and neutrons) within the nucleus. Mass Defect: -Apparent loss of mass when nucleons come together as some of the mass is converted into energy Binding energy: -That energy is called the binding energy
What physical qualities contribute to the capacitance of a capacitor?
Surface area, distance, and dielectric constant all contribute to the capacitance of a capacitor.
torque on a dipole in an electric field equation
T= p*E*sin(ϴ) p=magnitude of the dipole moment (p=qd) E=magnitude of the uniform external electric field theta=angle the dipole moment makes with the electric field
Torque on a dipole in an electric field
T= p*E*sin(ϴ) p=magnitude of the dipole moment (p=qd) E=magnitude of the uniform external electric field theta=angle the dipole moment makes with the electric field -torque causes the dipole to reorient itself so that the dipole moment (p) aligns with the electric field (E)
Period equation
T=1/f T=period (seconds per cycle) F=frequency (cycles per second)
heat of vaporization
The amount of energy required for the liquid at its boiling point to become a gas
what is the relationship between energy, work, and heat?
The change in internal energy of a system is equal to the heat added/removed from the system minus the work done by the system.
freezing/solidification
The change of state from a liquid to a solid
shock wave
The cone-shaped disturbance created by an object moving at supersonic speed through a fluid.
beat frequency
The difference between the frequencies of the two combining sound waves that make a beat.
The Photoelectric Effect
The emission of electrons from a material when light of certain frequencies shines on the surface of the material
sonic boom
The explosive sound heard when a shock wave from an object traveling faster than the speed of sound reaches a person's ears
resonant frequency
The frequency that is most strongly enhanced by resonance. The resonance frequency of a closed tube is determined by the length of the tube.
constructive interference
The interference that occurs when two waves combine to make a wave with a larger amplitude
destructive interference
The interference that occurs when two waves combine to make a wave with a smaller amplitude
laminar flow
The movement of water particles in straight-line paths that are parallel to the channel. The water particles move downstream without mixing.
equilibrium length
The natural length of a spring or springlike object when it is free of external forces and motionless.
Dispersion of light
The one exception to wave rule that speed is determined by medium and not frequency Light with different frequencies have slightly different speeds here -separation of light into different colors
instantaneous speed equation
The rate at which an object is moving at a given moment in time
Snell's Law
The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant, for a given frequency. -When light enters a medium with a higher index of reflection, it bends towards the normal -when light enters a medium with a lower index of refraction, it bends away from the normal.
second condition of equilibrium
The sum of the clockwise torques on a body in equilibrium must be equal to the sum of the counterclockwise torques about any point.
work-energy theorem
The work done on an object equals the change in kinetic energy of the object
If two objects are traveling toward each other, how does the apparent frequency differ from the original? what if two objects are traveling away from each other? what if one object is following the other?
Toward: -apparent frequency would be higher than the original frequency Away: -apparent frequency is lower than the original frequency Following: -could be higher or lower, depending on the speed of the detector and the source.
Electric potential near a dipole
V=(kqd/r^2)cos(theta): v=electric potential k= constant q=charge d=distance r=product of r1 and r2 to get r^2 -since p=qd: -p is the dipole moment -q=charge -d=charge separation distance Also can be written as: V=(kp/r^2)cos(theta): v=electric potential p= dipole monent r= distance between p and q
Ohm's Law
V=IR -voltage drop between any points in a circuit. V=voltage drop I=current R=resistance
electric potential equation
V=U/q v=kQ/r U=electric potential energy q= charge V= electric potential in volts k=constant Q= source charge
The electromagnetic Spectrum
VPGBYOR colors in the visible spectrum
critical speed equation
Vc=Nr(eta)/(rho)(D) -Vc = critical speed -Nr = Reynolds number (constant) -eta = viscosity of the fluid -rho = density -D = diameter of the tube the water is flowing through
velocity and speed
Velocity: -Vector -rate of displacement in a given unit of time -direction is not necessarily the same as the direction of displacement vector Speed: -rate of actual distance traveled in a given unit time
Kirchhoff's Laws
[circuits] 1. the sum of current flowing into a junction must equal the sum of the current leaving at any junction, -2. the sum of voltage sources = the sum of voltage drops around a closed-circuit loop. -consequence of the law of conservation of energy
Diffraction
a change in the direction of a wave when the wave finds an obstacle or an edge, such as an opening
direct current
a flow of electric charge in only one direction
centripetal force
a force that acts on a body moving in a circular path and is directed toward the center around which the body is moving.
positron
a particle that has the same mass as an electron, but has a positive charge, and is emitted from the nucleus during some kinds of radioactive decay
Thin film interference
a phenomenon in which a spectrum of colors is produced due to the constructive and destructive interference of light waves reflected in a thin film
boundary layer
a region of unstirred air or water that surrounds the surface of an object
electric dipole
a separation of equal and opposite charge by a small distance; can be seen in polar molecules. -results from two equal and opposite charges being separated by a small distance which can be transient (as in london dispersion force) or permanent (in case of the molecular dipole of water or the carbonyl group).
Harmonic series
a series of frequencies that includes the fundamental frequency and integral multiples of the fundamental frequency
SI units
a system of physical units ( SI Units ) based on the meter, kilogram, second, ampere, kelvin, candela, and mole, together with a set of prefixes to indicate multiplication or division by a power of ten.
cyclic process
a thermodynamic process in which a system returns to the same conditions under which it started
isothermal process
a thermodynamic process that takes place at constant temperature
isovolumetric process (isochoric)
a thermodynamic process that takes place at constant volume so that no work is done on or by the system
pitch
a tone's experienced highness or lowness; depends on frequency
gauss
a unit of magnetic induction, equal to one ten-thousandth of a tesla. 1 T = 10^4 gauss
Position of dark fringes in slit-lens setup
a*sin(Θ)= n*λ a= width of the slit theta = angle between the line drawn from the center of the lens to the dark fringe and the axis of the lens n=integer indicating the number of the fringe lamda = wavelength of the light
Pythagorean theorem
a²+b²=c²
intensity
average rate of energy transfer per area across a surface that is perpendicular to the wave.
Speed of light from frequency and wavelength
c= f* λ c=speed of light in a vacuum f=frequency lamda= wavelength
Position of dark fringes in double-slit setup
d= distance between two slits theta= angle between the line drawn from the midpoint between the two slits to the dark fringe and the normal n=integer indicating the number of the fringe lamba=wavelenght of the incident wave
beta negative decay
decay of a neutron into a proton, with emission of an electron and an antineutrino
Conservation of mechanical energy equation
deltaE = deltaU + deltaK = 0
Second law of thermodynamics equation
deltaS(universe) = deltaS(systm) + deltaS(surround) > 0
displacement vs distance
displacement: -final position - initial position -vector quantity distance: -physical distance traveled -scalar quantity
types of menisci
due to adhesive forces; backwards from what is intuitive concave: more common; u-shaped -water -volume should taken at bottom of meniscus convex: upside down u-shape; liquid level higher in the middle than at the edges -mercury -measurement should be taken at top of meniscus
metalic bond
electrons that are free to move from one electrically charged electron to the next -equal distribution of the charge density of free electrons across all of the neutral atoms within the metallic mass
Frequency of a standing wave (closed pipes)
f=nv/4L
True/False: To determine the volume of an object by fluid displacement it must have a specific gravity greater than one
false: -a fluid with a low specific gravity can be used instead of water to determines volumes of objects that would otherwise float in water.
What are the four fundamental forces of nature?
force of gravity electromagnetic force strong nuclear force weak nuclear force
four fundamental forces
gravity, electromagnetic force, strong nuclear force, weak nuclear force
Where are bright fringes located?
halfway between dark fringes -in both single-slit and double-slit experiments.
Conservation of Mechanical Energy
if there is no friction or air resistance, the mechanical energy of a system changes only if the system does work on something else or energy is added from outside the system.
What are the six simple machines?
inclined plane wedge wheel and axle lever pulley screw
coulomb's constant
k 8.988*10^9 N * m^2/C^2 -in SI units
Wavelength of a standing wave (closed pipes)
lambda = 4L/n
diverging lenses
lenses which bend light rays outward, causing them to diverge away from one another Diverging lenses (standard glasses) are needed by people who are "nearsighted"
fundamental pitch
lowest partial of the harmonic series; the pitch that is perceived as the sounding pitch
Magnification equation
m = -i/o; i=image size o=object size -Negative magnification signifies an inverted image, while a positive value signifies an upright image -If m<1, the image is smaller than the object (reduced) -if m>1, the image is bigger than the object (enlarged) -if m=1, the image is the same size as the object
magnification of multiple lens system
m = m1 x m2 x m3...
Isovolumetric Process (Isochoric)
no change in volume (vertical line on P-V) diagram no work accomplished (W = 0) ΔU=Q
adiabatic process
no heat exchange (Q=0) ΔU = -W
What are the requirements for a: nonzero electric field nonzero magnetic field nonzero magnetic force
nonzero electric field: -needs charge nonzero magnetic field -one needs a charge that is MOVING magnetic force -one needs an external field acting on a MOVING CHARGE acting any direction except parallel or antiparallel to the external field.
Indices of refraction of common media
not memorized, just for reference.
isotopic notation
notation that shows the chemical symbol, atomic number, and mass number for an isotope of an element
Critical angle equation
or Theta(c) = Inverse sin of (n2/n1)
What are examples of state functions?
pressure density temperature volume enthalpy internal energy gibbs free energy entropy
beta positive decay
proton decays into a neutron and a beta positive particle Z(daughter)= Z(parent) - 1 A (daughter)= A (Parent)
nucleons
protons and neutrons in the nucleus
Latent heat equation
q = mL L = latent heat (cal/g) m = mass
specific heat equation
q = mcΔT q=heat gained/loss m=mass c=specific heat of substance DeltaT=change in temperature (in celsius or kelvins)
Torque equation
r=length of the lever arm F=magnitude of the force Ѳ= angle between the lever arm and force vectors
Gamma decay equation
radioactive decay by emission of a gamma ray
energy density
ratio of energy per cubic meter -N*m/m^3 = J/m^3
How to determine the direction of the magnetic force on a moving charge OR in a current carrying wire
right hand rule: -position your right thumb in the direction of the velocity (or current direction/flow of positive charge) vector. -put your fingers in the direction of the magnetic field lines -your PALM points in the direction of the force vector for a POSITIVE charge -BACK of your hands points in the direction of the force vector for a NEGATIVE charge
Projectile motion Equation
s = 1/2(u+v)t s = ut +1/2at^2 s = vt - 1/2at^2 v = u + at v^2 = u^2 + 2 as
If the newton is the product of kilograms and meters/second^s, what units comprise the pound?
slug * ft/s^2
doppler ultrasound
study that uses high-frequency sound waves for detection of blood flow within the vessels -can be used therapeutically to treat kidney stones or destroy small tumors -also can be used for dental cleaning and for destruction of cataracts.
Lorentz force
sum of the electrostatic and magnetic forces acting on a body
source charge
the charge that creates an electric field
maximum kinetic energy of ejected electron
the difference between hƒ and hƒt W: work function = hƒt maximum b/c the actual kinetic energy depends on the specific subatomic interactions between the photon and the metal atom. -KEmax only occurs when all the energy of a photon is transferred to the ejected electron
Radius of curvature
the distance between the center of curvature and the mirror's surface
Kinetic energy
the energy an object has due to its motion
binding energy
the energy that holds a nucleus together, equal to the mass defect of the nucleus.
potential energy equation
u=mgh
center of curvature
useful when locating images, it is the center of the imaginary sphere upon which a curved mirror rests, the flatter the mirror, the farther away the center of curvature
propagation speed of a wave
v=fλ v=wave speed (m/s) f= frequency (Hz or s^1) λ=wavelength (m)
Speed of sound equation
v=sqrt(B/density) B=resistance to compression (lowest for gas and highest for solid), -p= density of medium. Solids with low density are the fastest and gas with high density are the slowest. approx 343 in air at 20*C
Thermal expansion equation (linear/rods)
ΔL=αLΔT -deltaL=change in length -a=coefficient of linear expansion -L=original length -deltaT=change in temp
First law of thermodynamics equation
ΔU = Q - W
Rate of nuclear decay
Δn/Δt = -λn
Translational Equilibrium
∑F=0 -stationary or constant nonzero velocity -constant speed and direction
