Question

Two loudspeakers emit 600 Hz Hz notes. One speaker sits on the ground. The other speaker is in the back of a pickup truck. You hear 7.00 beats per second as the truck drives away from you. What is the truck'sspeed?

Answer 1

Answer:

The truck's speed is 4.04 m/s.

Explanation:

Given that,

Emit frequency = 600 Hz

Beat = 7.00 beat/sec

We need to calculate the truck's speed

Using formula of speed

$\text{frequency observed}=\text{frequency emitted}\times\dfrac{v}{v+v_{source}}$

Where, v = speed of sound

Put the value into the formula

$(600-7)=600\times(\dfrac{343}{343-v_{truck}})$

$v_{truck}=\dfrac{600\times343-593\times343}{593}$

$v_{truck}=4.04\ m/s$

Hence, The truck's speed is 4.04 m/s.