Abaseball hits a car, breaking its window and triggering its alarm which sounds at a frequency of 1210 hz. what frequency (in hz) is heard by a boy on a bicycle riding away from the car at 8.25 m/s? take the speed of sound to be 343 m/s.

The frequency of sound heard by the boy is 1181 Hz.

Explanation:

Given that,

Frequency of sound from alarm  

Speed = -8.25 m/s

Negative sign show the boy riding away from the car

Speed of sound = 343

We need to calculate the heard frequency

Using formula of frequency

Where, = frequency of source

= speed of observer

= speed of source

= speed of sound

Put the value into the formula

here, source is at rest

Hence, The frequency of sound heard by the boy is 1181 Hz.

it is a negative acceleration