A source that emits radio waves produces a pulse aimed at a reflector. After bouncing back from the reflector, the pulse is detected again at the source position. Fig. 2.1 shows the outgoing pulse and the reflected pulse on a cathode-ray oscilloscope (c.r.o.). The time-base setting is $0.20\,\mu\text{s cm}^{-1}$.
(a)[4]
From Fig. 2.1, calculate the distance from the source to the reflector.
(b)[3]
Determine the time-base setting needed to give the same pulse separation on the c.r.o. when sound waves replace radio waves. The speed of sound is $300\,\text{m s}^{-1}$.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Use $d = vt$.” …