Question

A man standing 40m away from a wall fired a gun . calculate the time after which an echo is heard take the speed of sound as 320mspeed-1
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Answer 1

Answer:

Explanation:  t = 2D/ v       [this is the formula for echo]

                     then t = 2 x 40/320

                                 t = 0.25 s

          hope u get it mate.............................

Answer 2

Answer:

0.25 seconds

Explanation:

Given:

• Distance of the person from the wall who fired the gun = 40 metres
• Speed of the sound = 320 m/s

To find:

• Time after which the echo is heard

Distance will be 2d as the echo has to travel to the wall and again return back to the person

Time = $\frac{Distance}{Speed}$

Distance = 2×40

Distance = 80 metres

Speed of sound = 320 m/s

Time=$\frac{80}{320}$

Time=$\frac{1}{4} \ seconds$

The time after which the echo will be heard is equal to 0.25 seconds