A constant force acting on a body of mass 3.0 kg changes its speed from `2.0 m s^-1`to `3.5 m s^-1` in 25 s. The direction of the motion of the body remains unchanged. What is the magnitude and direction of the force ?

Explanation

We are given: `u= 2 ms^(-1), v= 3.5 m s^(-1)`
t = 25 s.
We are to calculate: Magnitude and direction of force
We know that, `v=u+at implies 3.5=2+25 xx a`. So `a=0.06 m s^(-2)`.
Mass of body, m = 3 kg. So, force acting on the body `F= ma = 3 xx 0.06 = 0.18 N`. Since applied force increases the speed of body, therefore it acts along the direction of motion.