A truck is moving in still air towards a massive vertical cliff at a steady speed of…
PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Waves Sound and Physical Optics · Waves Sound and Physical Optics
Problem
A truck is moving in still air towards a massive vertical cliff at a steady speed of 15ms−1 while sounding its horn continuously. When the front of the truck is 255m from the cliff, the driver suddenly switches the horn off and simultaneously starts a stopwatch. Take the speed of sound in air as 330ms−1.
(i) After how much time will the driver hear the last echo of the horn that was emitted just before it was switched off?
(ii) How far from the cliff will the truck be at the instant this echo is heard?