Practicing Success
A body of mass 3 kg is under a constant force which causes a displacement s in metres in it, given by the relation s = (1/3) t2, where t is in s. Work done by the force in 2 s is : |
(17/3)J (3/8)J (8/3)J (3/17)J |
(8/3)J |
Work-Energy theorem : W = \(\Delta\) K E W = \(\frac{1}{2}mv_1^2 + \frac{1}{2}mv_2^2\) Given : s = \(\frac{1}{3} t^2\) ⇒ v = \(\frac{ds}{dt} = \frac{2}{3}t\) \(v_1 = v(t = 0) = 0 \text{ ; } v_2 = v(t = 2) = \frac{4}{3} m/s\) ∴ W = \(\frac{8}{3}\) J |