Question:
A body of mass 2 kg travels according to the law x(t) = p(t) + qt2 + rt3 where p = 3 m/s, q = 4 m/s2, and r = 5 m/s3. The force acting on the body at t=2 seconds is
(a) 136 N
(b) 134 N
(c) 158 N
(d) 68 N
Solution:
The correct answer is a) 136 N