PHYSICS 112 FINAL EXAM REVIEW QUESTIONS
Wave - Answers - Particles that experience displacement through a medium
Mechanical Wave - Answers - Waves that propagate through a medium, i.e. NOT
ELECTROMAGNETIC WAVES
Anatomy of a Wave - Answers - a) Crest - maximums
b) Trough - minimums
c) Amplitude - rest to crest/trough
d) Wavelength - rest point to rest point
e) Frequency - # of waves
f) Period - time per cycle
What are the 4 types of mechanical waves? - Answers - 1. Periodic = periodic motion,
no restoring force
2. Sinusoidal = periodic motion, restoring force
3. Transverse = vibrates at right angle to direction of propagation; particle perpendicular
to motion
4. Longitudinal = vibrating in the direction of propagation
What 2 things can waves do? - Answers - Reflect and superimpose
Constructive Interference - Answers - When two or more waves combine to produce a
wave with a larger displacement (sum of amplitudes)
Destructive Interference - Answers - When two waves combine to make a wave with a
smaller amplitude OR cancels out
Standing Waves - Answers - Transfer no energy. They have the same amplitude and
are in phase. Happens when a wave & its reflection interfere (or just 2 waves)
Fundamental Frequencies - Answers - Depend on properties of resonant medium; if the
resonator is a string, cord, or wire, the standing wave pattern is a function of tension,
linear mass density, and length
Third Harmonic, n = 3 - Answers - 2nd overtone
Young's Double Slit Experiment - Answers - Light is projected onto a screen with 2
small slits. The light waves diffracting through the 2 slits interfere with one another and
produce a predictable pattern of alternating light and dark bands (maxima and minima)
on the detector screen.
Sound Intensity - Answers - Human ear = 20-20,000 Hz
,Ultrasonic is greater than
Infrasonic is less than
Decibel - Answers - Named after Alexander Graham Bell, 1/10 of a Bell, dimensionless
(no units)
Doppler Effect - Answers - A change in sound frequency caused by motion of the sound
source, motion of the listener, or both; closer = higher frequency
Law of Reflection - Answers - Bouncing back of light or sound waves in the same
medium, when it falls on a plane
What is the angle of incidence in reflection? - Answers - Equal to angle of reflection (so
theta i = theta r)
In reflection, the incident ray, reflected ray, and the _____________ all lie in the same
_____________. - Answers - normal; plane
Give an example of reflection - Answers - Mirrors
What are the two types of reflection? - Answers - Specular (regular) and diffuse
(irregular)
Specular Reflection - Answers - A reflection produced by a smooth surface in which
parallel light rays are reflected in parallel at the same angle as the incident angle
Diffuse Reflection - Answers - A reflection of light, which is incident, on a rough surface
and reflects light in diverse directions
Law of Refraction - Answers - Refraction is the change in direction of wave propagation
as it passes across the boundary separating two mediums and is caused by change in
speed
Give one example of refraction - Answers - Lenses
In refraction, the incident ray, refracted ray, and the ______________ all lie in the same
______________. - Answers - normal; plane
Snell's Law - Answers - n1sinθ1 = n2sinθ2
Relation between the incident and refraction angles and the refractive index of the
media
The angle of incidence in refraction is _________________ to the angle of refraction. -
Answers - NOT EQUAL
, Another way to define Snell's Law - Answers - Mathematical relationship for the precise
manner in which the direction of rays change during refraction
Optics terminology - Answers - So = optic distance
Si = image distance
C = center (radius of curvature)
OA/PA = optic axis/principal axis
Vertex = point where optical axis meets mirror
f = focal point
R = radius
If an object is on the same side as the incoming rays, then distance is
_________________. - Answers - Positive
If an object is on the same side as the outgoing rays, then distance is
_________________. - Answers - Positive
What are the 2 types of images? - Answers - Real and virtual
Real Image - Answers - Images seen in a mirror if light is passing through that image,
drawn as STRAIGHT lines
Virtual Image - Answers - Images that only appear if light is passing through, drawn as
DASHED lines
Magnification is based on a unit of _______. - Answers - one
What 2 natures can an image have? - Answers - Upright or inverted
Plane Mirror - Answers - Virtual, upright images
Distances in front = +
Distances in back = -
Magnification = 1
Objects = on optic axis
Law of Reflection = angle of incidence is equal to angle of reflection
Spherical Mirror - Answers - If m>0, image is upright
If m<0 image is inverted
Convex or Concave
Convex Mirror - Answers - Parallel lines diverge from focal point, outer surface is
reflecting
Concave Mirror - Answers - Converge at focal point after reflection, inner surface is
reflecting
Wave - Answers - Particles that experience displacement through a medium
Mechanical Wave - Answers - Waves that propagate through a medium, i.e. NOT
ELECTROMAGNETIC WAVES
Anatomy of a Wave - Answers - a) Crest - maximums
b) Trough - minimums
c) Amplitude - rest to crest/trough
d) Wavelength - rest point to rest point
e) Frequency - # of waves
f) Period - time per cycle
What are the 4 types of mechanical waves? - Answers - 1. Periodic = periodic motion,
no restoring force
2. Sinusoidal = periodic motion, restoring force
3. Transverse = vibrates at right angle to direction of propagation; particle perpendicular
to motion
4. Longitudinal = vibrating in the direction of propagation
What 2 things can waves do? - Answers - Reflect and superimpose
Constructive Interference - Answers - When two or more waves combine to produce a
wave with a larger displacement (sum of amplitudes)
Destructive Interference - Answers - When two waves combine to make a wave with a
smaller amplitude OR cancels out
Standing Waves - Answers - Transfer no energy. They have the same amplitude and
are in phase. Happens when a wave & its reflection interfere (or just 2 waves)
Fundamental Frequencies - Answers - Depend on properties of resonant medium; if the
resonator is a string, cord, or wire, the standing wave pattern is a function of tension,
linear mass density, and length
Third Harmonic, n = 3 - Answers - 2nd overtone
Young's Double Slit Experiment - Answers - Light is projected onto a screen with 2
small slits. The light waves diffracting through the 2 slits interfere with one another and
produce a predictable pattern of alternating light and dark bands (maxima and minima)
on the detector screen.
Sound Intensity - Answers - Human ear = 20-20,000 Hz
,Ultrasonic is greater than
Infrasonic is less than
Decibel - Answers - Named after Alexander Graham Bell, 1/10 of a Bell, dimensionless
(no units)
Doppler Effect - Answers - A change in sound frequency caused by motion of the sound
source, motion of the listener, or both; closer = higher frequency
Law of Reflection - Answers - Bouncing back of light or sound waves in the same
medium, when it falls on a plane
What is the angle of incidence in reflection? - Answers - Equal to angle of reflection (so
theta i = theta r)
In reflection, the incident ray, reflected ray, and the _____________ all lie in the same
_____________. - Answers - normal; plane
Give an example of reflection - Answers - Mirrors
What are the two types of reflection? - Answers - Specular (regular) and diffuse
(irregular)
Specular Reflection - Answers - A reflection produced by a smooth surface in which
parallel light rays are reflected in parallel at the same angle as the incident angle
Diffuse Reflection - Answers - A reflection of light, which is incident, on a rough surface
and reflects light in diverse directions
Law of Refraction - Answers - Refraction is the change in direction of wave propagation
as it passes across the boundary separating two mediums and is caused by change in
speed
Give one example of refraction - Answers - Lenses
In refraction, the incident ray, refracted ray, and the ______________ all lie in the same
______________. - Answers - normal; plane
Snell's Law - Answers - n1sinθ1 = n2sinθ2
Relation between the incident and refraction angles and the refractive index of the
media
The angle of incidence in refraction is _________________ to the angle of refraction. -
Answers - NOT EQUAL
, Another way to define Snell's Law - Answers - Mathematical relationship for the precise
manner in which the direction of rays change during refraction
Optics terminology - Answers - So = optic distance
Si = image distance
C = center (radius of curvature)
OA/PA = optic axis/principal axis
Vertex = point where optical axis meets mirror
f = focal point
R = radius
If an object is on the same side as the incoming rays, then distance is
_________________. - Answers - Positive
If an object is on the same side as the outgoing rays, then distance is
_________________. - Answers - Positive
What are the 2 types of images? - Answers - Real and virtual
Real Image - Answers - Images seen in a mirror if light is passing through that image,
drawn as STRAIGHT lines
Virtual Image - Answers - Images that only appear if light is passing through, drawn as
DASHED lines
Magnification is based on a unit of _______. - Answers - one
What 2 natures can an image have? - Answers - Upright or inverted
Plane Mirror - Answers - Virtual, upright images
Distances in front = +
Distances in back = -
Magnification = 1
Objects = on optic axis
Law of Reflection = angle of incidence is equal to angle of reflection
Spherical Mirror - Answers - If m>0, image is upright
If m<0 image is inverted
Convex or Concave
Convex Mirror - Answers - Parallel lines diverge from focal point, outer surface is
reflecting
Concave Mirror - Answers - Converge at focal point after reflection, inner surface is
reflecting
