Question 12
Work, Energy and PowerAn object of mass 20kg is released from a height of 10m above the ground level. The kinetic energy of the object just before it hits the ground is [g=10ms−2]
- A.4 000 J.
- B.2 000 J.
- C.500 J.
- D.200 J.
Show the answer and explanation
Answer: B (2 000 J.)
Explanation
All its potential energy becomes kinetic energy: KE = mgh = 20 × 10 × 10 = 2000 J.