Question 12
Work, Energy and PowerA body of mass 4kg is acted on by a constant force of 12N for 3 seconds. The kinetic energy gained by the body at the end of the time is
- A.162J.
- B.144J.
- C.72J.
- D.81J.
Show the answer and explanation
Answer: A (162J.)
Explanation
a = 12/4 = 3 m s−2, v = 3 × 3 = 9 m s−1, KE = ½ × 4 × 92 = 162 J.