Question

A force of 200 newton acts on a body of mass 40 kg for 4 second initially at rest calculate velocity and rate of change in momentum

Answer 1

Force = mass × Acceleration

200 N = 40 × Acceleration

Acceleration = 200/40

= 5 m/s²

Acceleration = Change in velocity / time

Change in velocity = Final velocity - initial velocity

= x - 0 = x (if we let final velocity to be x)

5 = x / 4

x = 5 × 4 = 20 m/s

Momentum = mass × Velocity

Initial momentum = 0 × 40 = 0kgms⁻¹

Final momentum = 20 × 40 = 800kgms⁻¹

Change in momentum = 800 - 0 = 800Kgms⁻¹

Rate of change of momentum = change in momentum /time

800 / 4 = 200 Kgms⁻²