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]
A
600 J
B
150J
C
300 J
D
450 J
Verified Correct Answer: C.
Physical Principles & Numerical Solution
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
Source: Myschool Past Questions Archive (Record #14353)