Physics- Velocity

Question

1. While at a track meet, you notice a time delay between when you see the starter’s pistol fire and when you hear it. If that delay is 0.4 seconds, how far away are you? Draw a picture of the situation.

Answer 1

The light reaches you at the speed of light which for all practical purposes is instantaneous in the scenario. Sound travels at 343 m/s in dry air at 20C. If the took 0.4 s after seeing the flash, the distance is

343 m/s x 0.4 s = 137 m.

I can't draw a picture but maybe you can.