Physics 3

Give an overview of charge.

(-) Charge = electrons ; (+) Charge = relatively fewer electrons

Demonstrate how to convert between Pascals, mmHg, atm and Torr in any order

1 x 10^5 Pascals = 1 atm = 760 mmHg = 760 Torr. One can use a conversion factor similar to those used for mole-to-mole conversions to get from any one unit to any other unit

PLEASE do these questions in the question set when you review this lesson! These contains info that is NOT in the lesson outline or new methods to apply to certain problems or just plain good practice for certain topic!

1, 2, 4, 5, 8, 9,

Define voltage and give its equations.

: Voltage = the amount of potential energy a system is capable of storing per unit charge (V = PE/q). o Another intuitive way to think of voltage: Voltage = the amount of work necessary to move a charge against an electric field. Moving the charge a longer distance against the field would require more work per unit charge, so that means more voltage. This aligns with the general observation that voltage increases with distance. If the electric field were stronger, moving a charge the same distance against the field would require more work per unit charge, so that would also mean more voltage. Both of these concepts are demonstrated in the two equations we've presented thus far for voltage: V = Ed and V = Kq/r (The second equation is also V = Ed, where E = Kq/r2; when multiplied by distance (r or d, it doesn't matter) one r is cancelled out leaving V = Kq/r).

What are electric dipoles?

A dipole is a separation of positive and negative charges of equal magnitude. When the MCAT discusses dipole they will either be two opposite charges of equal magnitude very near one another in space, or any object/ molecule with a charge separation-wherein one side bears a full or partial positive charge and another bears a full or partial negative charge (i.e, a polar bond) When a dipole is exposed to an electric field it will tend to align itself with that field. A dipole that is NOT aligned with the electric field has potential energy because alignment with the field is a lower energy state than alignment against the field.

What are point charge and constant electric fields?

A point charge field is an electric field created by a point charge. The strength of the electric field varies with the distance r from the point charge. A constant electric field, as the name implies, is constant and its strength does not vary with distance. Be aware that the MCAT tends to use the variable r for distance when discussing point charges and the variable d for distance when discussing constant electric fields (a.k.a., uniform electric fields). A constant electric field exists between the two plates of a parallel plate capacitor. The electric field is constant at any point between the plates (recall that closer lines represent a stronger field), voltage is NOT constant. We've seen quite a few students confuse this point. The equipotential lines show that voltage is constant if you move parallel to the plates, but not if you move perpendicular to the plates.

What are semi-conductor and super conductor?

A semiconductor is a material thought to be right in the middle of an insulator and a conductor (in terms of conductivity vs. resistivity). A superconductor is a material that under very precise conditions is thought to exhibit zero resistance to electron flow.

What is an insulator?

An insulator is a material with a very, very high resistivity. There is no perfect ideal insulator that allows zero current flow under all conditions. However, materials like glass and Teflon allow negligible current flow up to extremely high voltages.

What is the definition of electric field?

An invisible influence that can exert a force on a mass or a charge. Detail explanation: The space surrounding a charged object is affected by the presence of the charge; an electric field is established in that space. A charged object creates an electric field - an alteration of the space or field in the region that surrounds it. Other charges in that field would feel the unusual alteration of the space.

State the Archimedes' principle

Any object displaces an amount of fluid exactly equal to is own volume (if fully submerged) or to the volume of whatever fraction of the object is submerged (if floating). The weight of the displaced fluid is exactly equal to the buoyant force pushing up on the object.

An important note about batteries on the MCAT.

Anything that separates charge creates a voltage and can therefore be thought of as a type of battery (and treated accordingly). A few former MCAT questions have involved very "non-traditional" batteries not easily recognized as such. The key to recognizing them as batteries is to observe that they are causing a separation of charge.

Differentiate between atmospheric pressure, fluid pressure and gauge pressure.

Atmospheric pressure is the fluid pressure due to the earth's atmosphere at that location. You could conceptualize it as the weight of the column of air above that point—explaining why atmospheric pressure decreases with increased elevation; Fluid pressure is the force per unit area at some point within a fluid. Therefore, atmospheric pressure is really just a type of fluid pressure wherein air is the fluid. If we examine common usage, however, when people refer to "fluid pressure" they are usually referring to the pressure at some depth within a liquid. ; Gauge pressure is measured with respect to atmospheric pressure, where atmospheric pressure is defined as zero gauge pressure. Put another way, gauge pressure is the amount of pressure in excess of the ambient atmospheric pressure. The absolute pressure would be the actual total pressure of the atmosphere plus gauge pressure. An example most students are familiar with would be tire pressure. If your tire had a pressure of 1 atm at sea level, it would appear to you to have no pressure whatsoever. However, it clearly has some pressure—it is just the same pressure as the air around you. When you inflate the tire to 35psi you are really inflating it to 35psi ABOVE atmospheric pressure. Atmospheric pressure is about 15psi at sea level, so the actual total pressure is 50psi. It is the gauge pressure that is 35psi.

What is a bar magnet?

Bar magnets are usually made of nickel, iron, or an associated alloy. Normally, the electrons in a metal are approximately split between spin states, and thus the tiny magnetic fields they create cancel each other out. In a bar magnet they are partially aligned, creating a net magnetic field.

What are the formulas for capacitance and the potential energy stored by a capacitor?

C= Q/V U =1/2 C V^2

What is a capacitor?

Capacitors store energy and charge by holding electrons on plates separated by a very small distance. o Symbol: two vertical lines of equal length

State the relationship between electric field and magnetic field?

Changing electric fields create magnetic fields and changing magnetic fields create electric fields.  Any movement, velocity, rotation, etc., of a charged particle causes a change in the electric field created by that charge and thus creates a magnetic field.  All of the following involve moving charges and thus create a magnetic field:  Nuclei with and odd atomic or mass number (because they exhibit nuclear spin)  Electrons (because they orbit and spin)  Current (because it is moving electrons)

What is the difference between adhesion and cohesion?

Cohesive forces are intermolecular forces BETWEEN molecules of a liquid and bind molecules to one another. (we can switch to the term liquid instead of the term fluid that we've predominantly used up to this point because gases are defined as not having intermolecular forces). Adhesive forces are intermolecular forces between molecules of the liquid and molecules of the container (interaction between unlike molecules). This is well illustrated by the meniscus formed when water is in a burette. The adhesive forces are greater than the cohesive forces and therefore the water appears to "stick" to the sides of the burrette (i.e., concave up meniscus). Water droplets on a freshly waxed car are a good example of cohesive forces exceeding adhesive forces. There are intermolecular forces between the water and the surface of the car, but the cohesive forces between water molecules are greater, causing them to coalesce into a sphere-like droplet.

Describe the direction of current in circuit and its equation.

Current flows opposite to the direction of electron flow. o I = ∆q/∆t ; It is perhaps more intuitive to think of current as the amount of charge (i.e., electrons) that flows past a fixed point per unit time. o Current flows from positive (+) to negative (-) o Electrons flow from negative (-) to positive (+)

How does current flow through parallel resistors?

Current flows through parallel resistors is always apportioned inversely with resistance. If one resistor has twice the resistance, it will receive half the current.

What is the equation used to calculate density?

D=m/v Density of water; 1000kg/m^3 or 1.0g/cm^3; recall that 1cm^3=1ml, 1L of water = 1kg and 1ml of water =1 gram.

Describe the direction and field lines of electric field.

Electric field is a vector quantity whose direction is defined as the direction that a positive test charge would be pushed when placed in the field. Thus, the electric field direction about a positive source charge is always directed away from the positive source. And the electric field direction about a negative source charge is always directed toward the negative source. Always draw field lines with their tails at the positive charge pointing away or pointing toward the negative charge. Closer lines represent a stronger field; Lines further apart represent a weaker field.

Which way does current flow? Which way do the electrons flow? Explain how you conceptualize current. What is current made up of?

Electrons flow from the negative terminal to the positive, and current flows from the positive terminal to the negative. b) Current is the flow of electrons. Current cannot be intuited as a flow of positive charges from positive to negative as current is often defined. There are NO positive charges moving through the wires. The literal movement of charge is due entirely to moving electrons. In conceptual terms, this is the only way to think of and visualize current for the MCAT. This makes sense because we know that electrons congregated at a negative terminal on a battery do not like to be close to one another and will have potential energy that drives them to move toward the positive terminal. Just make it one of those important caveats that you keep close-at-hand that, in a totally counterintuitive way, someone defined the word "CURRENT" as flow in the exact opposite direction (positive to negative). Think of current as electrons, but remember the caveat.

What is the formula for force exerted by magnetic field?

F = qvB sin theta ; where theta is the angle between v and B. UNITS of B = N x s/C x m or Kg/A*s2

What is the equation used to calculate buoyant force? Give the important principle regarding buoyant force.

F of buoyant= p . v . g where v is the volume of fluid displaced, NOT the total volume of the fluid, and p is the density of the fluid ,NOT the object. The important principle is that the buoyant force is always exactly equal to the weight of the amount of fluid displaced by the object.

Describe in details the process of solving circuits using Ohm's law.

FIRST: You must have a simplified circuit. Simplified means no more than ONE of each component is present (one resistor, one battery, one capacitor). To arrive at a simplified circuit combine the circuit components according to the following rules: Resistors in series: add directly Resistors in parallel: add the inverses then take the inverse of the result. Capacitors in series: add the inverses then take the inverse of the result. Capacitors in parallel: add directly. Batteries in series: add directly. Batteries in parallel: total voltage= the highest voltage of any one of the batteries in parallel. SECOND: If the above steps do not yield a simplified circuit, try Kirchoff's rules. 1st rule: current into a node = current out of a node 2nd rule: In any circuit, Delta V= 0 (i.e, the sum of the voltage drops across each resistors equals to the total voltage of the battery) THIRD: You can use Ohm's law across a single resistor. Doing so may be necessary to get a piece of information needed to simplify the circuit. Be sure you are using only information for that resistor and NOT for the main battery, current through the circuit as a whole, etc. Ohm's law across a resistor states that: Voltage drop across THAT resistor = current through THAT resistor multiplied by the resistance of THAT resistor. FOURTH: When you have a simplified circuit you can use Ohm's law (V = IR) to solve for any of the three variables.

Do field lines best approximate electron flow or current flow?

Field lines should always be drawn with their tails toward the positive charge and their heads toward the negative charge. Current is said to flow from positive to negative, so it could be compared to the orientation of field lines. Electron flow, however, goes from a high concentration of electrons (negative charge) to a low concentration of electrons (positive charge)—or the exact opposite orientation.

What causes the buoyant force? How does the buoyant force change with depth? How does the buoyant force change with the mass of the object?

First, it is a characteristic of liquids (as compared to solids) that liquids can permanently resist a compressive force applied normal to their surface, but not parallel to their surface. Solids permanently resist both (up to the elastic limit of the solid). This gives us a rather general sense for the fact that liquids want to push objects up toward their surfaces. However, we think the best way to intuit buoyant force is to look at the pressure differential between the top and bottom of an object. The fluid pressure, pgh, will be larger at the object's bottom surface than it is at the top surface due to the larger value of the h term for the deeper surface. Let's examine a submerged cube with the same surface area both top and bottom. The formula P = F/A tells us that if pressure is greater at the bottom and area stays the same, there must be a greater force up on the bottom surface than there is down on the top surface. This makes it logical that any submerged object will experience a net upward force due to pressure differential. Buoyant force does not change with depth! This is because the change in depth between the top and bottom of the object does not depend on depth. Remind students that one of the best ways to predict how (or if) an entity is altered by a change to one specific variable is to look to see if the variable in question is in the formula for that entity. This can not only tell you if it does or does not have an impact on the value of the entity, but can tell you if that influence is linear, exponential, etc. In this case, depth (h) is not in the formula: F = pvg. Therefore, we can confidently conclude that depth does not change buoyant force. The conceptual approach we just described for understanding buoyant force would help us as well—whether the depth is shallow or very large, the pressure difference between pgh-top and pgh-bottom will remain the same. Similarly, we can say that the mass of the object does not affect buoyant force because it is not in the formula, nor accounted for by our understanding of what causes the buoyant force

What are the equations for voltage in electric field?

For gravity near earth V= gh --> For constant E field V=Ed For real gravity V = Gm/r --> For point charge E-field V= Kq/r

What are the force equations for electric field?

For gravity near earth: F = mg --> For constant E-field F= qE For real gravity F= Gm1m2/r^2 --> For point charge E-field F= Kq1q2/r^2 (Coulomb's law)

What are the electrical potential energy equations for electric field?

For gravity near earth: P=mgh (height h measured against g) --> for constant E-field: PE = qEd (d measure against E) For real gravity PE=-Gmm/r --> for point charge PE= -Kqq/r or Kqq/r

What are the strength equations for electric field?

For gravity near earth: g= F/m --> For constant E-field E= F/q or E= V/d For real gravity g= Gm/r^2 --> For point charge E field E= Kq/r^2

An important note about charge.

Forget about positrons and protons when it comes to circuits, electricity, currents, etc. When we are discussing electricity and circuits, positive charge is always a lack of electrons relative to being neutral where the proper number of electrons balances the stationary positive nuclei. Outside of radioactive decay or atomic bombs, protons and positrons tend to say in the nucleus and never move around.

Use Pascal's Law to explain the physics of a hydraulic lift.

In a hydraulic lift, we manipulate the fact that pressure must stay the same in a contained and incompressible fluid. At one end, we apply a force F1 to a small area (i.e, plunger) this create a pressure that will be transmit through the fluid.The pressure must have the same value at the other end of the hydraulic lift but with a much larger area. Looking at the equation P=F/A, we can see that in order to keep the pressure at the same value F2 must increase dramatically.

How does increasing or decreasing each of the following affect capacitance: plate area, plate thickness, distance between plates, strength of the dielectric and voltage.

Increasing plate area increases capacitance because there is more room available on the inside surface of the plate to store electrons. Electrons do not line up on the sides or back of the plate, so increasing plate thickness will have no effect on capacitance. Increasing the distance between the plates increases voltage for a given Q on the plates, which decreases capacitance according to C = Q/V. Increasing the strength of the dielectric increases capacitance because the dielectric impedes the buildup of the electric field between the plates and diverts some of the capacitor's finite energy storage capacity to realign dipoles inside the dielectric. Increased voltage, increases the charge stored but does not increase capacitance, which is the charge stored per voltage.

What is a common problem when it comes to manipulation of Ohm's law?

It CANNOT be said that if voltage increases and current remains constant resistance will increase! Resistance is a permanent quality of the resistor itself. Saying that increasing voltage will increase resistance is rather like saying that increasing force while acceleration is held constant will increase mass. Look again at the formula for resistance given earlier in this lesson. Notice that neither voltage nor current are in this equation. The only way to change the resistance is to either 1) physically remove one or more resistors from the circuit and replace them with other resistors that have different Ohms ratings, or 2) change the temperature of the resistor. If you were very careful you could say it this way: "If voltage increases, in order for current to remain constant I would need to increase the resistance." What will happen automatically if you increase voltage (without altering circuit components or temperature)? Current will simply increase.

What is surface tension?

It is the intensity of intermolecular forces at the surface of a liquid. Another explanation: The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension. The molecules at the surface do not have other like molecules on all sides of them and consequently they cohere more strongly to those directly associated with them on the surface. This forms a surface "film" which makes it more difficult to move an object through the surface than to move it when it is completely submersed.

What is the Bernoulli's equation?

K = P + pgh + 1/2pv^2 Bernoulli's equation demonstrates the law of conservation of energy; the random vibrational energy of the fluid molecules is given by P (a.k.a "Pressure Energy"); the gravitational potential energy per unit volume of the fluid is given by pgh where h is the height, not depth; and the kinetic energy per volume of moving fluid molecules is given by 1/2pv^2. The sum of these three forms of energy in an ideal fluid is always equal to constant K. Energy is transferred from one from to another but the sum will never change.

What materials are classified as conductors and insulators?

Metals such as copper typify conductors, while most non-metallic solids are said to be good insulators, having extremely high resistance to the flow of charge through them.

In the apparent weight (AW) equation, is it possible for AW to be greater than actual weight (aW)?

No. Apparent weight is accounted for by the fact that the actual weight of the object is reduced by the magnitude of the buoyant force. It only applies to objects more dense than the fluid. If the object were less dense than the fluid it would float. When an object is floating, mg (actual weight) = buoyant force, so by definition the apparent weight must be zero. To see this more clearly, rearrange the equation to: Fbuoyant + Apparent Weight = Actual Weight.

What are the equations for electrical power?

P = IV = I^2 R = V^2 / R Much like capacitance, only memorize P = IV and solve for the other two equations.

What is the fluid pressure formula?

P = pgh (unit is Pascals)  Fluid pressure can be thought of as the average force of molecular collisions per unit area, or as the weight of the column of fluid above the point of measurement. Note that here h is depth not height.

What is the general pressure formula?

P= F/A

Describe the concept of pressure as energy density.

P=F/A= (F.d)/(A.d)=Work/Volume or Energy/Volume Using this equation we can derive the kinetic energy and potential per unit fluid which are : K/V = 1/2mv^2 / V = 1/2 . p . v^2 PE/V = mgh / V = pgh

What are the two types of electric field?

Point charge fields : equate to real gravity or gravity in space Constant Electric field: equate to assumed gravity or gravity near earth.

Note on Pascal's law.

Pressure is a constant for any vertical depth within the same fluid; even if a convoluted pipe leads to that depth; even if the surface of the fluid is not directly above the point of measurement; and whether the container is 5 mm or 5 miles wide. In other words, if a pipe exits horizontally from a tank, the fluid pressure inside that pipe is the same as the fluid pressure inside the tank at that same vertical distance from the surface of the fluid.

Talk about the Pascal's Law.

Pressure is transmitted in all directions, undiminished, through a contained, incompressible fluid. Put another way, if pressure increases at any point in a confined, incompressible fluid, it increases by that same amount at every other point within that fluid.

Give the equation for flow rate.

Q=AV Area in this equation is always total cross-section area. Therefore, if a large pipe splits into to smaller pipes you must add the cross-sections of both new pipes to get the new area. Biology Connection: This formula is often used to describe fluid flow in the cardiovascular system. The variable A is the cross-sectional area of the blood or lymph vessel and V is velocity. Q is a function of cardiac output. Cardiac output = stroke volume x heart rate.

What is the formula for resistivity in circuits? State the relationship between resistivity and temperature.

R = ρL/A , where ρ = resistivity, L = length, A = cross-sectional area.  Temperature Dependence: Starting around room temperature, an increase in temperature results in a linear increase in resistivity. Changing temperature is the only way you can change resistance in a circuit without replacing the resistor.

Define resistance in circuits.

Resistance can be conceptualized as the equivalent of drag in fluids or friction between solids. The equation below describes resistance in circuits, but the same parameters are roughly applicable to heat flow and fluid flow.

Explain on the molecular level why increased temperature increases resistance

Resistance on the molecular level is a function of the ability of the electron to travel in a free path between atoms. Electrons flow through conductors by striking an atom and thereby ejecting one of the other electrons from that same atom. This process of absorbing and ejecting electrons is the slowest part of the process (i.e., the rate-limiting step). Therefore, the more time the electrons spend in free space between atoms the less "impeded" they will be and the faster they will flow through the conduit. Increased temperature causes increased movement of the atoms in the conduit, increasing the average number of collisions an electron will have with atoms and therefore increasing resistance.

Describe resistors in details.

SYMBOL: zig-zag line. There is always a voltage drop across any resistor when current flows through it. Internal resistance: Batteries experience internal resistance due to the resistivity of their internal components. This results in a voltage drop per the rule stated above and therefore decreases (slightly) the actual terminal voltage of the battery.

What is specific gravity?

Specific gravity is a ratio describe how dense something is compared to water. SG= D of substance/ D of H2O. For objects floating in liquids, the fraction of the object submerged= the ratio of the density of the object to the density of the liquid. If the liquid in which it is submerge is water, the fraction submerged is equal to the specific gravity.

Describe batteries in details.

Symbol: Two vertical lines of unequal length. The longer line represents the positive terminal and the shorter line represents the negative terminal. Think of Batteries as: Electron pumps that push electrons onto the negative terminal of the battery. This creates a separation of charge and therefore a potential difference between terminals that will drive electron flow around the circuit to the positive terminal.

Describe switches in details.

Symbol: a diagonal break in the line between circuit components. Closed = electrons flow; Open = no electron flow.

What should you think of magnetism as?

THINK OF MAGNETISM AS: Magnetism = Analogous to electricity, with these changes: 1) Replace positive charges with north poles 2) Replace negative charges with south poles 3) Magnetic field lines go from north to south instead of from positive to negative

Explain the terms "root mean square current" and "root mean square voltage" as they apply to household AC current.

The "root mean square" (RMS) method of calculating both voltage and current are necessary for,alternating current applications because the current and voltage over time are sinusoidal. This creates a problem because the average of a sine wave centered at the origin is zero. If you randomly sampled the voltage in your household wiring it could literally have a voltage of 120V one instant and a voltage of -120V the next instant. That would average to zero, even though the alternating current does deliver a continuously useful source of power (It can dissipate energy during both cycles). Power companies therefore use the RMS method to calculate the average power delivered to your home (otherwise, according to P = V2/R if V averages to zero you don't owe the power company anything!). RMS is just a mathematical calculation and it can be applied to voltage, current, to sine waves, or even to other waveforms such as square waves. To find RMS, you take readings at various time intervals, square all of those readings, take the average of those squares (i.e., the mean of the squares) and then take the square root of that average. You should understand this mathematical process for the MCAT as well as the general idea behind why it is necessary. It would also be helpful to know that the rms voltage (or current) is equal to the equivalent DC voltage (or current) that would deliver the same amount of power.

How would you calculate the apparent weight of a submerged object?

The apparent weight of a submerged object is the actual weight minus the buoyant force: Apparent weight= Actual Weight - F buoyant

Use Q = AV to explain how velocity varies as blood flows throughout the human circulatory system.

The cross-sectional area of individual vessels decreases as you go from the aorta to the capillaries. However, it is the TOTAL cross-sectional area that we would apply to Q =AV. Total cross-sectional area increases as you go from aorta to capillaries. Because area is greatest at the capillaries, the velocity of blood is lowest at the capillaries. The reverse is true on the return trip: cross-sectional area decreases as we go from capillaries back to the vena cava. Therefore, velocity increases.

What is a dielectric?

The dielectric is the substance between the two plates. All capacitors have a dielectric, even if it is just air. Other dielectrics are often inserted between the plates, such as gels or composites. Once inserted, some energy stored in the capacitor is used to align the polar molecules in the dielectric (i.e., dipoles) with the field between the plates. Increasing the strength of the dielectric increases the capacitance allowing more charge and energy to be stored. Increasing dielectric strength, increases capacitance. The dielectric must always be an insulator.

Using the apparent weight formula, what information can you obtain by manipulating actual weight and apparent weight?

The difference between the actual weight and the apparent weight tells you: 1) the buoyant force and 2) the weight of the volume of fluid.

What are the primary differences between AC and DC current? which type is utilized by household electric wiring, automobile electronics, and your cell phone, respectively? Which one can be represented by a sine wave?

The letters AC in "AC Current" stands for "alternating current," and the letters DC in "DC Current" stand for "direct current." Direct current is about what it sounds like, the direct flow of current through a circuit from positive to negative (or in terms of electron flow from negative to positive). DC current is the kind of power used in automobiles because it comes directly from the battery. In fact, if something uses a battery you would be perfectly safe on the MCAT to assume that it must be an example of DC current. This would therefore include all automobile electronics, anything you plug into the cigarette lighter (unless it is an inverter of course), your cell phone (battery), etc. Household wiring utilizes AC current. Alternating current is also about what it sounds like—both the polarity of the voltage and the direction of the current periodically reverse. A graph of current versus time for an AC current creates a sine wave.

Describe electric charge value and unit.

The unit of electric charge is the Coulomb (abbreviated C). Ordinary matter is made up of atoms which have positively charged nuclei and negatively charged electrons surrounding them. Charge is quantized as a multiple of the electron or proton charge: -e= -1.6 x 10^-19 or e= 1.6 x 10^-19

Talk about the concept of conservation of charge.

The universe always has zero net charge. Charge is created by separation. If you separate one electron from a neutral atom you have created one independent unit of negative charge (the electron), but you have simultaneously created one independent unit of positive charge (the cation).

What assumption can you make for a circuit wires resistance?

The wires between any two elements in a circuit are assumed to be perfect conductors (i.e., resistance here = zero; all resistance occurs at the resistors)

What is a conductor? What is a resistor?

These are all relative terms. A conductor is a material that allows the flow of electrons through it relatively unimpeded. A resistor is a material that tends to impede the flow of electrons. This being said, even the best conductors do exhibit some small degree of resistance to the flow of electrons (superconductors being the possible exception), and all resistors do conduct electrons to some small degree.

What are equipotential lines?

These lines are drawn perpendicular to field lines and represent areas of equal voltage (i.e, electric potential)

What are the application of Bernoulli's equation?

This principle is commonly applied to the flow of an ideal fluid through a horizontal pipe, in which, if fluid velocity increases then pressure decreases. This can occur where the fluid encounters a section of pipe with a smaller cross-sectional area. In order to maintain flow rate, the velocity must increase in the narrower section of pipe. In order to maintain constant K in the equation, an increase in the kinetic energy (through an increase in velocity) must be accompanied by a decrease in one or both of the other terms. In this case it is the P term. If the increase in velocity were also associated with a decrease in height, both the P term and pgh term would decrease and both would contribute to an increase in the 1/2pv^2 term. Another common application of this principle is to the velocity of water exiting a spigot. The potential energy of the water in the tank near the top (pgh term) is converted to the kinetic energy of the flowing water at the spigot (1/2pv^2)

What are different types of fluid flow?

Types of Fluid Flow: o Ideal, Non-Viscous Flow: This is how ideal, non-viscous fluids flow. There is assumed to be no friction (drag) between the fluid and the walls of the pipe, or between fluid molecules themselves. Fluid near the wall of the pipe flows with the same velocity as fluid at the center of the pipe. This is assumed on the MCAT if they do not specify otherwise. o Poiseuille Flow: This is how real, viscous fluids flow in pipes. Real fluids exhibit laminar flow (defined below) and have a leading edge that is parabolic in shape. o Laminar Flow: Fluid flows in pipes in concentric sheets, each with different velocities. The fastest flow is at the exact center of the pipe and the slowest is at the interface with the wall of the pipe. o Turbulence: At low velocities real fluids exhibit laminar flow. As velocity increases, and especially for non-viscous fluids, flow becomes turbulent—meaning that although the net flow is still in one direction, there are random eddies, changes in direction, changes in velocity, and so forth.

What is Ohm's law?

V = IR

Describe the two additional to describe voltage.

Voltage = potential energy / charge or mass V= PE/q Voltage = whatever entity you can multiply by mass or charge to get PE (gh x m = mgh = PE of gravitational and Ed * q = PE of electrical = V*q)

Comparing electric field equations to gravity.

g (strength of gravitational field) = E (strength of electric field) G (constant) = K (constant) h (distance) = r or d (both variables are used for distance in electric field equations) m (mass) = q (charge) F = F gh (gravitational potential) = V (voltage, electrical potential)