A force of 6 N acts on a body at rest and of mass 1 kg. During this time, the body attains a velocity of 30 m/*. The time for which the force acts on the body is
(a) 7 seconds
(b) 5 seconds
(c) 10 seconds
(d) 8 seconds
Correct option (b) 5 seconds
Explanation:
Force (F) = 6 N; Initial velocity (u) = 0; Mass (m) = 1 kg and final velocity (v) = 30 m/*.
Therefore acceleration (a) = F/m = 6/1 = 6m/s2
final velocity (v) = 30 = u + at = 0 + 6 x t
or t = 5 seconds.
