The number of cycles of a wave passing a point per unit time is the wave's __________.
Fill in the blank(s) with correct word
[Ques. 2] You put one ear on a steel railroad track while your friend a distance of 400 m away taps on the rail with a stone. You will hear the sound through the steel rail in _________ and through the air where the speed of sound is 344 m/s in _______.
a. 0.08 s b. 0.5 s
c. 1.2 s d. 2.4 s
[Ques. 3] In order for two waves to interfere completely destructively, they must
a. have the same amplitude.
b. be exactly out of phase.
c. one wave's peak must align with the other's valley.
d. be transverse waves.
e. all of the above
[Ques. 4] In a plane wave, the wavefronts are
a. circular.
b. flat.
c. parallel.
d. perpendicular to the direction of propagation.
[Ques. 5] An example of a longitudinal wave is
a. a sound wave in air.
b. a wave on a rope.
c. a water wave.
d. a sound wave in a metal bar.
e. none of the above.
[Ques. 6] An example of a transverse wave is a
a. sound wave in air.
b. wave on a rope.
c. water wave.
d. sound wave in a metal bar.
e. none of the above
[Ques. 7] Sound waves propagate in
a. one dimension. b. two dimensions.
c. three dimensions. d. four dimensions.
[Ques. 8] You are on a boat in a fog and know there are cliffs ahead of you somewhere, but you cannot see them. You use your fog horn to send out a blast of sound (assume the temperature of the air is 20 oC) and the time it takes for the sound to return to you is 20.0 s. How far away are the cliffs (in metric units)? Hint: Be careful and think about the physics of the problem. You may want to make a sketch of the situation to help you determine the answer.
a. 1798 m b. 3444 m
c. 3596 m d. 7192 m
[Ques. 9] You are on an island where a huge explosion at a distance of 500 miles away can be heard. How long (in seconds) does it take the sound to travel to your location? Assume the temperature of the air is 20 oC.
a. 1.4 s b. 5.6 s
c. 2340 s d. 8955 s
[Ques. 10] What frequency of sound traveling in air at 40 oC has a wavelength of 0.50 m?
a. 20 Hz b. 344.7 Hz
c. 502.9 Hz d. 711.2 Hz
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