Experiments with waves

Question 1

How do you measure the speed of sound using an oscilloscope

Answer 1

1. Set up the oscilloscope so the detcted waves at each microphone are shown as seperate waves
2. Start with both microphones next to the speaker, then slowly move on away until the two waves are aligned on the display, but have moved exactly one wave length apart
3. Measure the distnace between the microphones to find one wavelength (upside down y)
4. Use wave speed = frequency × wavelength
   v = f λ

Question 2

How do you measure the speed of water ripples using a lamp

Answer 2

1. Dim the lights and turn on the lamp
2. Measure the distance between shadow lines that are 10 wavelengths apart, then divide this distance by 10 to find the average wavelength
3. Alternatively you couldtake a phoyoof the shadows and ruler
4. Use wave speed = frequency × wavelength
   v = f λ