A carpenter on top of a roof of 20.0m high dropped a hammer of mass 1.5 kg and it fell directly to the ground. the kinetic energy of the hammer just before hitting the ground is?
[g = 10 ms-2]
- 600 J
- 150J
-
300 J
- 450 J
The correct answer is: C
Explanation
K e just before hitting the gound= P e at the maximum height (conservation of mechanical energy)
K e = P e = mgh = 1.5 x 10 x 20
= 300 J
There is an explanation video available .