Question

a force of 20N acting on a body of mass 10kg is found to double its velocity in 8s. Find its initial velocity.

Answer 1

Let the initial velocity be u.

Then the final velocity, v = 2u

F = 20 and m = 10 kg

F = ma

a = F / m = 20 / 10 = 2 m/s²

t = 8 sec

Using the equation,

v = u + at

2u = u +2x8

u = 16 m/s.