Consider a vibrating string that makes a sound wave that moves through the air. As the guitar string moves up and down, the air molecules that are a certain horizontal distance from the string will move
a. up and down.
b. toward and away from the guitar string.
c. back and forth along the direction of the length of the string.
d. in circles around the guitar string.
[Ques. 2] The Doppler shift for electromagnetic radiation from distant galaxies moving away from the observer is called a:
a. red shift.
b. blue shift.
c. black shift.
d. vacuum shift.
[Ques. 3] A series of ocean waves, 7.0 m between crests, move past at 4.0 waves/s. Find their speed.
a. 1.8 m/s
b. 7.0 m/s
c. 11.0 m/s
d. 28 m/s
e. 3.0 m/s
[Ques. 4] In the Doppler effect for electromagnetic waves, which of the following gives the greatest shift in frequency?
a. the source moving toward the non-moving observer at speed v
b. the observer moving toward the non-moving source at speed v
c. the source moving toward the approaching observer, both at speed v/2
d. All of the above give the same shift.
[Ques. 5] A sound wave coming from a tuba has a wavelength of 1.10 m and travels to your ears at a speed of 253 m/s. What is the frequency of the sound you hear?
a. 278 Hz
b. 1/278 Hz
c. 230 Hz
d. 1/230 Hz
e. 252 Hz
[Ques. 6] Star 1 is approaching the Earth with speed v. Star 2 is receding from the Earth with the same speed v. Measurements of the same spectral line from each of the stars show Doppler shifts in frequency. The light from which star will have the larger magnitude shift in frequency?
a. star 1
b. Both stars will have the same shift.
c. The value of the speed must be known before an answer can be found.
d. star 2
[Ques. 7] When a sine wave is used to represent a sound wave, the crest corresponds to
a. rarefaction.
b. condensation.
c. point where molecules vibrate at a right angle to the direction of wave travel.
d. region of low elasticity.
[Ques. 8] Which type of electromagnetic wave has the largest wavelength?
a. gamma rays
b. radio waves
c. x-rays
d. visible light
[Ques. 9] A spherical surface surrounds a point charge it its center. If the charge is doubled and if the radius of the surface is also doubled, what happens to the electric flux E out of the surface and the magnitude E of the electric field at the surface as a result of these doublings?
a. E and E do not change.
b. E increases and E remains the same.
c. E increases and E decreases.
d. E increases and E increases.
[Ques. 10] Find the frequency of x-rays of wavelength 1.75 1010 m. (c = 3 108 m/s)
a. 1.71E+12 Hz
b. 3.43E+19 Hz
c. 1.71E+18 Hz
d. 3.43E+9 Hz
e. 4.29E+14 Hz
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