Question

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

Answer 1

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