A car moving at 20m/s with its horn blowing (f = 1200Hz) is chasing another car going at 15m/s. What is the apparent frequency of the horn as heard by the driver being chased?

TheLivingLegend01

3 years ago

The apparent frequency of the horn heard by the driver being chased can be calculated using the Doppler effect formula:

f' = f (v + u) / (v + v_r)

where
f = frequency of the horn (source frequency)
v = speed of sound (assumed to be 343 m/s at standard conditions)
u = speed of the source (car with the horn)
v_r = speed of the receiver (car being chased)
f' = apparent frequency of the horn heard by the receiver
Substituting the given values:

f = 1200 Hz
v = 343 m/s
u = 20 m/s
v_r = 15 m/s

f' = 1200 x (343 + 20) / (343 + 15) = 1316.76 Hz

Therefore, the apparent frequency of the horn heard by the driver being chased is approximately 1.32 kHz, which is closest to option A (1.22 kHz). So, the answer is A. 1.22 kHz.

BlessingLB

1 year ago

physics is always confusing which particular topic is this on

Ndakotsu123

1 year ago

This answer is confusing.

Toclay

5 years ago

Where do u got ur 340 please

Victor1564

2 years ago

Since the velocity of the source is higher than the observer, it means that the source is moving closer to the observer and at the same time the frequency of heard by the observer is increasing.

The numerator has to be 340+15