A car is moving with a speed of 72 $kmh^{- 1}$towards a hill. Car blows horn at a distance of 1800 m from the hill. If echo is heard after 10s, the speed of sound $\left( in\ ms^{- 1} \right)$is

Question

Dr. Abubacker · Accepted Answer

(c) The speed of the car is 72$kmh^{- 1}$
$= 72 	imes \frac{5}{18} = 20{ms}^{- 1}$
The distance travelled by sound in reaching the hill and coming back to the moving driver
=1800+(1800-200)=3400m
So, the speed of sound=
$\frac{3400}{10} = 340ms^{- 1}$

Q. A car is moving with a speed of 72 $kmh^{- 1}$towards a hill. Car blows horn at a distance of 1800 m from the hill. If echo is heard after 10s, the speed of sound $\left( in\ ms^{- 1} \right)$is

Explanation

Reviewed by Dr. Abubacker

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