Question

a time keeper in a 100m run is advised to start the stop watch by seeing the smoke from the starts's gun and not hearing the sound of the fire . why​

Answer 1

Answer:

Explanation:

Sound seems to travel very fast, when we talk to each other it seems as if we hear the sound as soon as the lips of the other person move.

In fact it does take the sound some time to travel and you can tell this if you watch a cricket match or see a pile driver banging in a pile. You will notice that you see the bat hit the ball or the pile driver hit the pile before you hear the sound.

This means that:

Sound travels much more slowly than light.

This is why people timing sprints will always look for the puff of smoke from the starting pistol and not wait until they hear the bang before they start their stopwatches.