A force of 10 N acts on a body at rest and of mass 2 kg. During this time, the body attains a veloci

Question

A force of 10 N acts on a body at rest and of mass 2 kg. During this time, the body attains a velocity of $40 \mathrm{~m} / \mathrm{s}$. The time for which the force acts on the body is

Professor PC Thomas Classes · Answer

Force $F = 10 \mathrm{~N}$, Mass $m = 2 \mathrm{~kg}$. Acceleration $a = \frac{F}{m} = \frac{10}{2} = 5 \mathrm{~m/s}^2$. Initial velocity $u = 0$, final velocity $v = 40 \mathrm{~m/s}$. Using $v = u + at \implies 40 = 0 + 5t \implies t = 8$ seconds.