Question

A body of mass 50g is moving with the velocity of 10 ms^-1. It is brought to rest by a resistive force of 10 N Find.

1) the retardation and 

2) the distance that the body will travel after the resistive force is applied.

Answer 1

Mass of body = 50g = 0.050 kg

intial velocity,  u = 10 m/s

Final velocity, v = 0 m/s

Resistive force, F = 10 N

1) Force, F= ma

10N  = 0.050 x a

Acceleration, a = 10/00.5 = 2000 ms^-2

Retardation = - acceleration  = 200 ms^-2

2) From equation `v^2 - u^2 = 2as`

`0^2 - (10)^2 = 2 xx  (-200) xx s`

`-100 = -400 xx s`

S = 100/400 = 0.25 m = 25 cm