A constant force acting on a body of mass `3 kg` changes its speed from `2ms^(-1)` to `3.5 ms^(-1)` in 25 s. The direction of motion of the body remains unchanged. Calculate magnitude and direction of the force.

Explanation

m = 3.0 kg , u = 2.0 `ms^(-1)` v = 3.5 `ms^(-1)` , t = 25 g
As F = ma
or F = m(v-u/t) [`since` a = v-u / t]
implies F = 3.0(3.5 - 2.0) / 25 = 0.18 N .
The force is along the direciton of motion .