A constant retarding force of 50 N is applied to a body of mass 20 kg moving inintially with a speed of `15ms^(-1)` . How long does the body take to stop ?

Explanation

Here , F = - 50 N , m = 20 kg
u = `15ms^(-1) `, v = 0 , t = ?
From `F=ma,a =(F)/(m)=(-50)/(20)=-2.5ms^(-2)`
From `v=u+at,0=15-2.5t`
`t=(15)/(2.5)=6s`