Ch. 14, 25 Exam Review 1) A tsunami, an ocean wave generated by ...

Ch. 14, 25 Exam Review
1) A tsunami, an ocean wave generated by an earthquake, propagates along the open
ocean at 690 km/hr and has a wavelength of 650 km. What is the frequency of the waves
in such a tsunami?
2.9 x 10 -4 Hz
2) A 11.0-m rope is pulled taut with a tension of 120 N. It takes 0.545 s for a wave to
propagate along the rope. What is the mass of the rope?
3.24 kg
3) A fisherman fishing from a pier observes that the float on his line bobs up and down,
taking 4.4 s to move from its highest to its lowest point. He also estimates that the
distance between adjacent wave crests is 58 m. What is the speed of the waves going past
the pier?
6.6 m/s
4) A 5.00-m length of rope has a mass of 800 g. It is pulled taught with a force of 100 N.
What is the speed of waves on the rope?
25 m/s
5) A car horn emits a frequency of 400 Hz. A car traveling at 25.0 m/s sounds the horn
as it approaches a stationary pedestrian. What frequency does the pedestrian hear?
431 Hz

6) The speed of sound through the ground is about 6.0 km/s while the speed of sound in
air is 343 m/s. A very powerful explosion occurs some distance away and you feel the
ground vibrate 45 seconds before you hear the sound of the explosion. How far away is
the explosion?
16 km
7) A factory siren indicating the end of a shift has a frequency of 80 Hz. What frequency
is perceived by the occupant of a car traveling towards the factory at 25 m/s?
86 Hz
8) How does a sound of 60 decibels compare to a sound of 30 decibels?
1000 times as intense, each 10 dB increase is a tenfold increase in intensity
9) If the intensity level of one trombone is 50 dB, what is the intensity level of 56
trombones?
67 DB
10) You drop a stone down a well that is 8.50 m deep. How long is it before you hear the
splash?
1.34 s