A stone is thrown from the edge of a cliff into the ocean below. It is thrown somewhat upward, but mostly outward. The stone has a mass of 2.0kg and is thrown with a speed of 10m/s from an initial height of 5.0m above the ocean.

A. What is the kinetic energy of the stone when it is thrown?
B. What is the Potential energy of the stone relative to the ocean when it is first thrown?
C. What is the kinetic energy of the stone just as it hits the water?
D. What is the speed with which the stone hits the water?

1 answer

(a)KE=mv²/2
(b) PE=mgh
(c) KE1=KE+PE
(d) mv₁²/2= mv²/2+mgh
v₁= sqrt(v² +2gh)