Question

A force acts for 0.1 s on a body of mass 2.0 kg initially at rest. The force is then withdrawn and the body moves with a velocity of 2 m s^-1. Find the magnitude of the force. 

Answer 1

Mass, m = 2.0 kg i.e. 2 kg

Initial velocity, u = 0

Final velocity, v = 2 m/s

Time, t = 0.1 s

Acceleration = `"Change in velocity"/"time"`

∴ a = `("v" - "u")/"t"`

∴ a = `(2 - 0)/0.1`

∴ a = 20 ms^-2.

Force = Mass × Acceleration

⇒ F = 2 × 20

∴ F = 40 N.