Question
WJEC Unit 1 — Foundation
A fishing boat uses sonar to detect the seabed. An ultrasonic pulse is sent downward and the echo returns 0.12 seconds later. The speed of sound in seawater is 1 500 m/s.
(a) Explain why sound cannot travel in a vacuum, but electromagnetic waves can. (2 marks) (b) Calculate the depth of the seabed below the boat. (3 marks) (c) State one other use of ultrasound in medicine or industry. (1 mark)
6 marks · take your time before peeking.
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Generated by TopMyGrade AI · cross-check official sources before relying on the mark-scheme phrasing.