A force of 200N acting on a body of mass 20kg initially at rest causes it to move a distance of 320m along a straight line for t secs. Find the value of t.
-
A.
4s -
B.
6s -
C.
8s -
D.
10s
Correct Answer: Option C
Explanation
F = ma
(200 = 20a implies a = 10m/s^{2})
(s = ut + frac{1}{2}at^{2})
(320 = (0 times t) + frac{1}{2} 10t^{2})
(320 = 5t^{2} implies t^{2} = 64)
(t = 8secs)