A Man throws a ball towards a wall which is 74m away.After the ball hitting the wall he runs towards the wall and hears sound after0.2s.The temperature was 30c.what was the velocity of man?

1 Answer
Mar 4, 2018

Let the velocity of man be #v# m/s

Velocity of sound in still air at 0^@C or 273K is #V_273=331.5# m/s.

So velocity sound in still air at #30^@C# i.e. at 303K will be

#V_303=303/273*V_273=303/273*331.5= 367.9# m/s.

Now by the problem

#0.2*v+0.2*V_303=74#

#=>v+367.9=370#

#=>v=2.1#m/s