RP 8

Question 1

Describe how to use a ripple tank to measure the wavelength.

Answer 1

1. Set up ripple tank.
2. Place ruler on paper and freeze the image using a phone.
3. Measure the length of 10 waves together.
4. Find one wavelength by dividing the length of the waves by the number of wave lengths (aka 10).

Question 2

Describe how to use a ripple tank to measure the frequency.

Answer 2

1. Set up ripple tank.
2. Place timer next to paper.
3. Record and count number of waves passing a point in 10 second using timer and phone.
4. Calculate the number of waves passing a point in 1 second by dividing the number of wave that passed a point in 10 seconds by 10.

Question 3

Describe the two ways to use a ripple tank to measure the wave speed.

Answer 3

• Use the wave length and frequency found in previous practicals to calculate wave speed using: frequency × wave length.
• Select a wave and measure how long it takes for it to travel the length of the tank by doing: speed = distance / time

Question 4

Describe how to measure the wavelength and speed of waves in a solid.

Answer 4

1. Set up string with pulley and mass on wooden bridge and vibration generator with signal generator.
2. Turn on power and change frequency to get standing wave.
3. Mesure total length of standing wave from wooden bridge to vibration generator using ruler.
   - (a) Calculate speed of wave using: wave speed = frequency × wave length.
   - (b) Calculate wave length by diving total wavelength by number of half-waves, then multiplying by 2.