A body of mass 500 g, initially at rest, is acted upon by a force which causes it to move a distance of 4 m in 2 sec. Calculate the force applied.
Solution: mass=m = 500 g = 0.5 kg
Initial velocity = u = 0
Distance travelled = s=4 m
Time duration =t= 2 sec
As there is a force, so the motion will be an accelerated motion.
Let the acceleration is a.
From eqn, s = ut + ½ . a. t^2 = ½ . a. t^2 [as u=0]
4 = ½ . a . 2^2
So force applied= m a = 0.5 . 2 N =1 N