PS 5.2 - Wave Problems

 

1.     A sound wave produced by a clock chime is heard 515 m away 1.50 s later.

a.     What is the speed of the sound of the clockÕs chime in air? 343 m/s

b.     The sound wave has a frequency of 436 Hz. What is the period? 2.3 x 10-3 s

c.     What is the wavelength? 0.787 m

 

2.     A hiker shouts toward a vertical cliff 685 m away. The echo is heard 4.00 s later.

a.     What is the speed of sound of the hikerÕs voice in air? 171 m/s

b.     The wavelength of the sound is 0.750 m. What is the frequency? 228 cycles/s

c.     What is the period of the wave? 4.4 x 10-3 s

 

3.     What is the speed of a periodic wave disturbance that has a frequency of 2.50 Hz and a wavelength of 0.600 m? 1.5 m/s

 

4.     The speed of a transverse wave in a sting is 15.0 m/s. If a source produces a disturbance that has a frequency of 5.00 Hz. What is its wavelength? 3.0 m

 

5.     Five pulses are generated every 0.100 s in a tank of water. What is the speed of propagation of the wave if the wavelength of the surface wave is 1.20 cm? f= 50 pulses/s, v = 60. cm/s or 0.60 m/s (the latter is better!)

 

6.     A periodic longitudinal wave that has frequency of 20.0 Hz travels along a coil spring. If distance between successive compressions is 0.400 m, what is the speed of the wave? 8.0 m/s

 

Wave Behaviour Problems

 

 

 

 

  1. If waves maintain a constant speed, what will happen to their wavelength if the frequency of the waves is (a) doubled? Half (b) halved? Doubled

 

  1. What is the frequency of a sound wave if its speed is 340 m/s and its wavelength is 1.70 m? 200 Hz

 

  1. Waves of frequency 2.0 Hz are generated at the end of a long steel spring. What is their wavelength of the waves travel along the spring with a speed of 3.0 m/s? 1.5 m

 

  1. A student measures the speed of water waves in her tank to be 25 cm/s. If the wavelength is 2.5 cm, what is the frequency of the waves? 10 Hz

 

  1. The speed of light is 3.0 x 108 m/s. What is the frequency of light waves if their wavelength is 600 nm? (1 nm = 10-9 m) Consult a spectrum chart to see what colour of light this would be. 5.0 x 1014 Hz (green)

 

  1. Some microwaves have a frequency of 3.0 x 1010 Hz. How long is a microwave of the frequency? (Microwave radiation travels at the speed of light.) 0.010 m