Experiments With Waves

Question 1

Describe the setup and process for using two microphones and an oscilloscope to find the wavespeed of sound waves.
(Practical)

Answer 1

1)set up the oscillisope so the detected waves at each microphone are shown as seperate waves
2)start with both microphones next to the speaker (which is attached to a signal generator) and then slowly move one away untill the two waves are allignes but one wave length apart
3)meaure the distance between the mcrophones for one wavelength and then use the formula wave speed=frequency x wavelength,the frequency is whatever the signal generator is set too

Question 2

Describe the process for measuring the wavespeed of water waves using shadow lines on a screen below the tank (practical)

Answer 2

1)Use signal generator attached to a ripple tank dipper for a specific frequency
2)Dim lab lights, use lamp to cast wave crests as shadows on screen.
3)Measure the distance between shadow lines that are 10 wavelengths apart , divide by 10 for average wavelength.
4)Calculate wave speed using v = f × wavelength.

Question 3

Describe the steps involved in using the wave equation for waves on string (practical):

Answer 3

1)Connect vibration transducer and signal generator, attach to string on pulley with masses.
2)Activate signal generator and vibration transducer for string vibration.
3)Adjust signal generator frequency for clear wave appearance on string.
4)Measure lengths of 4 or 5 half-wavelengths, find mean half-wavelength.
5)Double mean half-wavelength for full wavelength.
5)Wave speed= wave length x frequency where f is the signal generator frequency