a flash of gun is seen by a man 3 seconds before the sound is heard .calculate the distance of the gun frim the man.(speed of sound in air is 332 m/s) 

Asked by rajivjoshigoldtech | 10th Mar, 2017, 08:34: PM

Expert Answer:

A flash of gun is mainly seen because of the reflection of the light followed by the light reception of the human eyes.
This indicates that the event actually seen was travelling with the speed of light which is 3 cross times 10 to the power of 8 .
time of seeing the flash = t
time at which the sound is heard = t+3
we know that
 speed equals distance over time
distance equals speed space cross times space time
distance travelled by light of the flash = distance travelled by the sound wave ... (a hypothetical assumption for this numerical)
3 cross times 10 to the power of 8cross times space straight t=332 cross times left parenthesis straight t plus 3 right parenthesis
3 cross times 10 to the power of 8straight t minus 332 straight t=996
The above substraction in the LHS is quiet negligible, therefore it remains unchanged.
3 cross times 10 to the power of 8 straight t=996
straight t equals fraction numerator 996 over denominator 3 cross times 10 to the power of 8 end fraction
Distance of the gun from the observer = speed of light cross times space straight t
Therefore the distance of the gun from the observer is 996 m.

Answered by Abhijeet Mishra | 11th Mar, 2017, 08:39: PM