A constant retarding force of 50 N is applied to a body of mass 10 kg moving initially with a speed of 10 ms-1. The body comes to rest after

Here, F = -50 N (-ve sign for retardation)        M = 10 kg, u = 10 ms-1,   v = 0As      F = ma          a = Fm = -50 N10 kg = -5 ms-2Using v = u + at           t = v-ua = 0-10 ms-1-5 ms-2 = 2 s