77 terms

# PHY 101 exam 4

exam 4
###### PLAY
A common source of wave motion is a
vibrating object
(sound waves are produce by vibrations of sound)
In a longitudinal wave the compressions and rarefactions travel in
same direction
Traverse wave (perpendicular)
Radio waves travel at the speed of light, 300,000 km/s. The wavelength of a radio wave received at
100 megahertz is
wave speed= frequency*wavelength
3.0m
An object that completes 100 vibrations in 5 seconds has a period of
vibrations/ second
none of the above
A Doppler effect occurs when a source of sound moves
..either towards you or away from you.
The source of a sonic boom
must itself an emitter of sound
The pendulum with the greatest frequency is the pendulum with the
shortest lenght
A floating leaf oscillates up and down two complete cycles in one second as a water wave passes
by. The wave's wavelength is 10 meters. What is the wave's speed?
hrtz* meters
As a train of water waves goes by, a piece of cork floating on the water bobs up and down one
complete cycle each second. The waves are 2 meters long. What is the speed of the wave?
hrtz*meters
If at a concert you run toward the orchestra, the frequency of the sound you hear will be
increased
A sound source of high frequency emits a high
pitch
Sound waves cannot travel in
a vacum
A wave having a frequency of 1000 hertz vibrates at
1000 cycles per second
The explanation for refraction must involve a change in
speed
The phenomenon of beats results from sound
interference
A 340-hertz sound wave travels at 340 m/s in air with a wavelength of
speed/hertz=wavelenght
1m
Inhaling helium increases the pitch of your voice. One reason for this is that sound travels
faster in helium than air
A piano tuner knows that a key on the piano is tuned to the frequency of his tuning fork when he
strikes them at the same time and the number of beats he hears each second is
f1-f2=0
if it is tune you do not hear anything
An ampere is a unit of electrical
current
Which statement is correct?
charge flows in a closed circuit
The current through a 10-ohm resistor connected to a 120-V power supply is
12 A
When a 10-V battery is connected to a resistor, the current in the resistor is 2 A. What is the
resistor's value?
ohms
The source of electrons lighting an incandescent ac light bulb is
atoms in the light bulb filament
When two lamps are connected in parallel to a battery, the electrical resistance that the battery
senses is
less than the resistance of either lamp
When two lamps are connected in series to a battery, the electrical resistance that the battery senses
i
more than the resistance of either lamp
When two 1-ohm resistors are connected in series, their combined resistance is
2 ohms and when in paralle., 1/2 ohm
If 0.8 A of current flow through a light bulb connected to a 120 V outlet, the power consumed is
Current * voltage
Electromagnetic waves consist of
oscillating electric and magnetic fields
Compared to ultraviolet waves, the wavelength of infrared waves is
longer
Compared to radio waves, the velocity of visible light waves in a vacuum is
the same
Compared to its average speed in air, the average speed of a beam of light in glass is
less
Materials generally become warmer when light is
absorbed by them
A lunar eclipse occurs when the
moon passes into earth's shadow
The sensation of color is seen when light falls on the eye's
cones
Which of the following cannot travel in a vacuum?
a sound wave
A pair of sunglasses and a pair of clear reading glasses are left in the sunlight. The hotter glasses
would be the
sunglasses
The incident light ray, the reflected light ray, and the normal between them
lie in the same plane
Object and image for a plane mirror lie
distance seen in the mirror is the same distance from the the mirror
To see his full height, a boy that is 1 meter tall needs a mirror that is at least
its always 1/2 the size
A diver shines light up to the surface of a smooth pond at a 10-degree angle to the normal. Some
light passes into the air above, and the part that reflects back into the water makes an angle to the
normal of
10 degrees
angle of incidence equal angle of refraction
Standing at the shore of a still lake, the reflected view of scenery on the far side of the lake is the
view you would see if you were upside down with your eye in the line of sight
directly beneath you, as far below water level as you are above
The inversion of your image in a plane mirror is actually an inversion of
front back
(plane mirror)
Atmospheric refraction makes the daylight hours a bit
longer
Light refracts when traveling from air into glass because light
travels slower in glass then in air (refraction)
When you view a distant rainbow, each single water drop contributes to the bow
a single color
dispersions of light by a single drop
The type of lens that spreads parallel light is a
diverging lens
When seen from an airplane, a rainbow sometimes forms a complete circle. When this happens, the
in the center of the rainbow
If you wish to spear a fish with a regular spear, you should compensate for refraction between the
air and water and throw your spear
below the sighted fish
If you wish to send a beam of laser light to a space station that is just above the atmosphere near the
horizon, you should aim your laser
along your line of sight
A mirage occurs for road surfaces that are
warm
If the speed of light in a medium is 2 × 108 m/s, the medium's index of refraction is
speed of light in a vacum / velocity in the material gives you N
electro magnetic spectrom lowest frequency
red
electro magnetic spectrom highest frequency
violet
trend among wavelength and frequency
high wavelength low frequency and vise versa
list from longest to shortest wavelenghts
radio, microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays
list from highest to lowest in average speed of light
vacuum, water, glass, diamond
they free electrons when light is shinning on in them
metals
lunar eclipse
moon is in earth shawdow
solar eclipse
moon shadow falls in earth (umbra)
umbra (sharp)
partial shawdow
penumbra (Fuzzy)
convex mirror
smaller image
concave mirror
larger image
law of reflection has to do with?
light and sound
diffuse reflection
occurs in rough surfaces
refracted light that bends toward and bends away
sped up , and slowed down
atmospheric refraction
is the cause of mirages
what does roy g biv stand for
bend more bend less
red, orange, yellow, green, blue, violet
converging lens
produce and upside down image
infrasonic
below 20 hertz
ultrasonic
above 20,000 hertz
where does sound travel faster in liquids or in air?
liquids
reflection sound is
echo
(hard surfaces cause greater echo)
sound bends upward and downward when ?
upward morning (warm air)
downward evening (cool air)
interference is a property of
light and sound
what is the difference between light and sound in wave properties
light is electromagnetic and sound is mechanical
trend in pendulum
longer the length of the pendulum longer the period
NOT DEPENDENT ON MASS