An ultrasonic non-destructive testing (NDT) probe is used to detect internal flaws in a thick titanium alloy block. The speed of the ultrasonic longitudinal waves in this alloy is 6100 m s-1.
An ultrasonic pulse is emitted from the probe on the surface of the block. The pulse travels vertically downwards, reflects off a horizontal crack at a depth of 18.3 cm, and returns to the probe.
What is the time interval between the emission of the pulse and the detection of the reflected echo?
15 μs15\text{ }\mu\text{s}15 μs
30 μs30\text{ }\mu\text{s}30 μs
60 μs60\text{ }\mu\text{s}60 μs
120 μs120\text{ }\mu\text{s}120 μs
11 exam-style questions on OCR GCSE Physics Wave interactions. Each one has a worked solution and a mark scheme showing where the marks go.