Question

A force of 4N acts on a body of mass 2 kg for 4 seconds. Assuming the body to be initially at rest find its velocity when the froce stops acting

Answer 1

Force = F = 4 N
Mass = m = 2 kg
Time = t = 4 sec
Initial velocity = u = 0
Let final velocity be v

A constant force acts on the body. So, the body has uniform accelerating.

Acceleration a = F/m = 4/2 = 2 m/s^2


Now, v = u + at
So, v = 0 + (2)(4)
So, v = 8 m/s


Thus, final velocity of the body is 8 m/s

Answer 2

F = 4N

M = 2kg

T = 4 sec

U = 0

Let the final velocity be v.

A = F/M = 4/2 = 2m/s square

V = U+AT

V = 0+(2*4)

V = 0+8 = 8m/s