contestada

A ball is thrown directly downward with an initial speed of 8.00 m/s, from a height of 30.0m. After what time interval does it strike the ground?

Respuesta :

The acceleration is -9.8m/s^2. The initial velocity is -8m/s. The initial position is 30m. This describes a position function of
-(9.8/2)t^2-8t+30=0
Solve the quadratic equation for t to get t=1.789s