Question

A student kicks a ball of 1 kg with a velocity of 13ms. The contact is 0.2 sec. Find the force

Answer 1

65 N

Step-by-step explanation:

Given that :

Mass of ball = 1kg

Velocity = 13m/s

Time = 2 seconds

Using the relation :

Force = (mass * change in velocity) / time

The change in momentum of the ball :

Momentum = mass * change in velocity

Velocity change = (13 - 0) ; Given that initial velocity = 0 (at rest)

Momentum = 1kg * 13m/s

Momentum = 13 kgm/s

Therefore, the force, F equals;

F = change in momentum / time

F = 13kgm/s ÷ 0.2 s

Hence, Force, F = 65N

Answer 2

65 N

Step-by-step explanation:

Assuming that the ball was at rest hence initial momentum = 0

Final momentum = mv = 1Kg × 13 ms-1 = 13 kgms-1

But

Ft= mv according to Newton's law

F= mv/t

F= 13kgms-1/0.2s

F= 65 N