A rock is thrown downward into a well that is 7.6 m deep. if the splash is heard 1.0 seconds later, what was the initial speed of the rock?

Respuesta :

Use s=ut+ 1/2 a t^2
T =1.0sec
S=7.6m
g = 9.81 m/s^2. (or 10 at GCSE)