Question

John fires again towards the hill and here is a echo after 5 seconds he then move 320 M towards the hill and fires his gun again this time he hears echo after 3 seconds calculate the velocity of the sound

Answer 1

let the distance if John and the hill initially be x
so, the net distance travelled by the sound will be 2x
afeas time is 5s here
so, velocity=2x/5 m/s
Again, after moving 320 m towards the hill the net distance travelled by sound will be 2x-2×320=2x-640 m
and here time taken is 3s
so, velocity=2x-640 /3 m /s

but as the speed of sound is same so equating both the velocity we get,
2x/5=(2x-640)/3
or,6x=10x-3200
or, 4x=3200
so, x=3200/4=800 m
so, velocity of sound=2×800/5=1600/5=320 m/s
Thanks.