Physics · Oct / Nov 2020 · Paper 12 · Question 27

A scientific research boat uses pulses of ultrasound to detect fish underneath it. A pulse of ultrasound is bounced from a group of fish 6000 m directly below the boat. The next pulse is sent out 2.0 s after the echo from the previous pulse has been received. The speed of ultrasound in water is 1500 m / s. What is the interval between the two pulses?

1. A4.0 s
2. B6.0 s
3. C8.0 s
4. D10 s

As printed in the paper