Physics 101

Homework #7 ½

1) The vibrations of a longitudinal wave move in a direction

a) along the direction of wave travel b) perpendicular to the direction of wave travel

2) If the frequency of a certain wave is 0.1 hertz, its period is

a) 0.1 seconds b) 10 seconds c) 100 seconds d) none of these

3) A 60 vibration-per-second wave has a length of 5 meters. The speed of this wave is

a) 120 m/s b) 30 m/s c) 300 m/s d) 1/120 m/s

4) During a single period, the distance traveled by a wave is

a) one-half wavelength b) one wavelength c) two wavelengths

5) Double the frequency of a sound and you halve its

a) wavelength b) speed c) amplitude d) all of these

6) Sound travels faster in

a) air b) water c) steel d) vacuum

7) Sound waves can interfere with one another so that no sound results

a) true b) false

8) The loudness of a sound wave is most closely related to its

a) speed b) frequency c) wavelength d) amplitude

9) A decibel is a measure of a sound’s

a) frequency b) wavelength c) speed d) loudness

10) Compared to a sound of 30 decibels, a sound of 50 decibels is

a) twice as intense b) 10 times as intense

c) 100 times as intense d) 1000 times as intense