Question

A vehicle traveling away from an observer has a malfunctioning horn that sounds continuously.
If the vehicle travels with a constant positive acceleration away from the observer, which of the following represents the magnitude of the change in frequency experienced by the observer over time?

A. Δf is constant over time
B. Δf increases linearly over time
C. Δf increases exponentially over time
D. Δf decreases linearly over time

Answer 1

Answer:

30) B; To analyze this question, recall the equation for Doppler, Δf/f = v/c. This demonstrates that the change in frequency is directly proportional to the relative velocity. If the acceleration is constant, the velocity is changing at a constant rate, so anything directly proportional to that must be changing at a constant rate. Because no squares or roots are involved, it must be linear, not exponential, making B the best answer.

Explanation: