Question

A wave sent out from a source is reflected back to the source in 1.9x10^-3 seconds .if the velocity of the wave is 3.0x10^8 m/s, the distance of the reflecting surface from the source is ?

Answer 1

d=V*T = 3*10^8 * (1.9*10^-3/2) = 2.85*10^5 m.