Answer:
The speed of the ambulance is 4.30 m/s
Explanation:
Given:
Frequency of the ambulance, f = 1790 Hz
Frequency at the cyclist, f' = 1780 Hz
Speed of the cyclist, v₀ = 2.36 m/s
let the velocity of the ambulance be 'vₓ'
Now,
the Doppler effect is given as:

where, v is the speed of sound
since the ambulance is moving towards the cyclist. thus, the sign will be positive
thus,

on substituting the values, we get

or
vₓ = 4.30 m/s
Hence, <u>the speed of the ambulance is 4.30 m/s</u>