Physics (AS & A Level) · May / June 2023 · Paper 11 · Question 22

A car travels at a constant speed along a straight line PQ. A loudspeaker attached to the car emits sound of constant frequency f. A stationary observer is at point O. What does the observer hear as the car moves from P towards Q?

1. Aa frequency less than f that decreases as the car moves from P towards Q
2. Ba frequency less than f that increases as the car moves from P towards Q
3. Ca frequency more than f that decreases as the car moves from P towards Q
4. Da frequency more than f that increases as the car moves from P towards Q

As printed in the paper