Physics · Oct / Nov 2018 · Paper 11 · Question 36

The diagram shows the trace on an oscilloscope screen. The first peak occurs when a pulse of sound is emitted. The second, smaller peak is the echo received from a wall. The trace moves across the screen in a time of 24 ms. How long does it take for the sound to travel to the wall?

1. A4.5 ms
2. B9.0 ms
3. C12 ms
4. D32 ms

As printed in the paper