An autonomous underwater vehicle (AUV) surveying a deep oceanic trench emits a brief, high-intensity acoustic pulse (ping) directed horizontally towards a vertical trench wall.
After a brief interval, the AUV's hydrophone registers a weak returned pulse. Explain why this second acoustic signal is detected and why its amplitude is significantly lower than that of the original pulse.
The time elapsed between emitting the acoustic pulse and receiving the reflected signal is 0.84 s0.84\text{ s}0.84 s. The speed of sound in seawater at this temperature and depth is 1500 m/s1500\text{ m/s}1500 m/s. Calculate the distance from the AUV to the trench wall.
The AUV then transmits two distinct continuous-wave calibration signals: Signal A and Signal B.
Explain how the wavelength of Signal A compares to the wavelength of Signal B.
Practise OCR GCSE Physics Wave behaviour with exam-style questions for Foundation and Higher tier. 100 questions, matched to the OCR GCSE Physics (J249) specification and written in Paper 1 and Paper 2 (Foundation Tier) or Paper 3 and Paper 4 (Higher Tier) style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.