An operator sitting in his base camp sends a sound signal of frequency 400 Hz. The signal is reflected back from a car moving towards him. The frequency of the reflected sound is found to be 410 Hz. Find the speed of the car. Speed of sound in air = 324 m s^-1.
The signal received by the car is given by,

This signal is reflected back. So,

But in both cases the moving object is the car. So, v_s=vo=u

So,

Question

The signal received by the car is given by,

This signal is reflected back. So,

But in both cases the moving object is the car. So, v_s=vo=u

So,

Philoid · Accepted Answer

The signal received by the car is given by,

This signal is reflected back. So,

But in both cases the moving object is the car. So, v_s=vo=u

So,