Physics · Oct / Nov 2018 · Paper 12 · Question 27

Ultrasound is used to map the ocean floor. During one survey, the depth of water is 1200 m. An ultrasound pulse is sent from the surface and when it returns to the ship, another pulse is sent immediately. In any period of 8.0 s, five pulses are sent down from the surface. What is the speed of the ultrasound in water?

1. A150 m / s
2. B300 m / s
3. C750 m / s
4. D1500 m / s

As printed in the paper