Kaplan physics Ch 7-8-9

For the magnification, what do positive and negative values signal for?

+ = image is upright - = image is negative

For the distance between the image and the mirror, what do positive and negative values signal for?

+ = in front of the mirror (real) - = image is behind the mirror (virtual)

For a distance of the focal point from the mirror, what do positive and negative values signal for?

+ = mirror is concave (converging) - = mirror is convex (diverging)

For a radius of curvature, what do positive and negative values signal for?

+ = mirror is concave (converging) - = mirror is convex (diverging)

For the distance between the object and the mirror, what do positive and negative values signal for?

+ = object is in front of the mirror - = object is behind the mirror (not on the MCAT)

what is the range of frequency a human being can hear?

20 to 20,000 Hz

What is the speed of light?

3.00 x 10^8 m/s

What is the Doppler effect?

A change in sound frequency caused by motion of the sound source, motion of the listener, or both.

_____________ are transverse waves because the oscillating electric and magnetic field vectors are perpendicular to the direction of propagation.

Electromagnetic waves

equation for calculating decibels

I = intensity of the sound wave Io = threshold of hearing (other bases can be used) B = decibels the threshold of hearing is 1 x 10^-12 W/m^-2

The average rate of energy transfer per area across the surface is perpendicular to the wave is known as -------. What is the equation that determines this?

Intensity

When the image (i) has a negative value, what does this mean?

It is a virtual image and thus located behind the mirror

What is forced oscillation?

Oscillations that occur when a system is made to oscillate by a periodic external force

what are ultrasonic waves?

Sound frequencies over 20,000 Hz cannot be heard by people

________________ is a blurring of the periphery of an image as a result of inadequate reflection of parallel beams at the edge of a mirror, or inadequate reflection of parallel beams.

Spherical aberration

What is the critical angle?

The angle of incidence when the angle of refraction is 90 degrees

What is wavelength?

The distance from one maximum crest to another

What is the focal length?

The distance from the center of the lens to the principal focus

What is the center of curvature?

The point in the center of the sphere from which the mirror was sliced.

What is a longitudinal wave?

The wave energy moves parallel to the direction of the vibration

What are diffraction gratings?

They are multiple slits arranged in patterns. they can create colorful patterns

what is lens power?

This is the distance of a lens and it principle focus or focal point over one usually measured in diopters: P = 1/f f = focal length

what is the radius of curvature?

This the point from the center of curvature from the vertex of the mirror

_______________ is a phenomenon in which all the light incident on a boundary is reflected back into the original material.

Total internal reflection this results from any angle of incidence greater than the critical angle.

What is destructive interference?

When the combined amplitude of two waves is smaller than the original waves can be partially destructive as well

When is an image considered "real"?

When the light that produces the image actually converges at the position of the image.

What is dispersion?

When various wavelengths of light separate from each other this is predominant in spherical lenses.

What is the principle if superposition?

When waves interact with each other, the displacement of the resultant wave at any point is the sum of the displacements of the resultant wave at any point is the sum of the displacement of the two interacting waves.

What is constructive interference?

Where two waves arrive in step reinforcing one another (increasing the amplitude) waves can be partially constructive as well

what are plane mirrors?

a mirror that has a flat surface

An object is placed 6 cm in from of a concave mirror that has a 10 cm radius of curvature. Determine the image distance, the magnification, and whether the image is real or virtual, inverted or upright.

a positive value for I signifies that the image is in front of the mirror. For a single lens or mirror with o > 0, a real image will always be inverted. negative sign confirms that the image is inverted the absolute value of the image is greater than 0, meaning it is enlarged.

Sound waves will naturally diminish through friction, air resistance, and viscous drag, this process is called _________.

attenuation (damping)

------ will cause the amplitude of a wave to decrease

attenuation (damping) from friction in a hypothetical frictionless environment, wave energy will increase indefinitely.

When the medium has a lower index of refraction when light enters it, which way does it bend?

away from the normal

Equation for the speed of sound:

bulk modulus is a measure of the medium's resistance to compression

equation for speed of light

c = speed of light f = frequency delta = wavelength

an object that do not allow oscillation and that correspond to nodes are called -----.

closed boundaries the closed end of a pipe and the secured end of a string are examples of this.

a pipe that is closed at one end is called a _____.

closed pipe

If we were to look from the inside of a sphere to its surface, we would see a ___________.

concave surface

Concave mirrors are called _____________ since the converge light rays to a single point.

converging mirrors

If we were to look from outside the sphere, we would see a ________

convex surface

Convex mirrors are called __________ because they diverge light rays.

diverging mirrors

Equation for Doppler Effect:

f' = perceived frequency f = emitted frequency v = speed of sound in medium vD = speed of the detector vS = speed of the source for signs, the top one is used when the detector is moving toward the other object the bottom sign is used when the object is moving away from the detector.

What is hyperopia?

farsightedness: can see far objects, not close ones needs a lens that causes convergence of light.

equation for beat frequency

fbeat = |f1 - f2|

what property of light follows the same pattern as energy?

frequency

The lowest frequency (or longest wavelength) of a standing wave that can be supported in a given length of a string is known as the -------.

fundamental frequency or first harmonic

trace the level of energy of electromagnetic radiation from highest to lowest energy.

gamma ray > X-ray > UV > vis light > infared > microwaves > radiowaves

What is chromatic aberration?

is a dispersive effect within a spherical lens It depends on the thickness and curvature of a lens.

What is sound?

it is a longitudinal wave transmitted by the oscillation of particles in a deformable medium

When the image (i) has a positive value, what does this mean?

it is a real image

What is a doppler ultrasound?

it is used to determine the flow of blood within the body by detecting the frequency shift that is associated with movement toward or away from the receiver.

_____ refract light while mirrors reflect it.

lenses

equation for magnification:

magnification is a dimensionless value that is the ratio of the image distance to the object distance.

What are antinodes?

midway between the node and is the fluctuation at maximum amplitude.

What is myopia?

nearsightedness: can see close objects, not far ones. needs a lens that causes divergence of light.

The ________ is a line drawn perpendicular to the boundary of a medium. All angles in optics are _________ from the ___________, not the surface of the medium.

normal, measured, normal

What is the period?

number of seconds per cycle: T = 1/f T: period

------- allow maximal oscillation and correspond to antinodes.

open boundaries the open end of a pipe and the free end of a flag

a pipe that is open on both ends is called a _____.

open pipe

what is pitch?

our subjective impression about the frequency of sound

What are nodes?

points of a wave that remain at rest

What is timbre?

quality of sound

________ is the rebounding of light waves at the boundary of a medium.

reflection

________ is the bending of light as it passes from one medium to another and changes speed.

refraction

If the frequency is equal to a natural (resonant) frequency of the system, then the system is said to be ----- ?

resonating the amplitude of the oscillation is at a maximum

equation for the standing wave and the length L of an open pipe.

same as the string, the real difference is for the closed pipe....

What is harmonic frequency?

the number of half-wavelengths supported by the string.

What is frequency?

the number of waves that pass a given point per second

What is a focal point?

the point at which the light rays meet

what are infrasonic waves?

the range of sounds below what humans can hear sound frequencies below 20 Hz

When the medium has a higher index of refraction when light enters it, which way does it bend?

toward the normal

true or false: the incident angle is always measured with respect to the normal

true

What are sinusoidal waves?

two type: transverse or longitudinal individual particles oscillate back and forth with a displacement that follows a sinusoidal pattern.

What is a transverse wave?

waves in which the particles vibrate in an up and down motion

What is the photoelectric effect?

when light of a sufficiently high frequency (typically blue or ultraviolet light) is incident on a metal in a vacuum, the metal atoms emit electrons.

What is rectilinear propagation?

when light travels through a homogeneous medium, it travels in a straight line

When is an image considered "virtual"?

when the light only appears to be coming from the position of the image.

equation for Snell's law

θ 1 and 2= angle to the medium with respect to the normal