Question

A soccer ball (mass = 0.43 kg) is moving at a speed of 20 m/s when it is kicked with a force of 300 N resulting in it going in the opposite direction with the same speed as before. What is the magnitude of the impulse delivered to the ball?

Answer 1

8.6 kgm/s or 8.6 Ns

Step-by-step explanation:

Given:

Mass, m = 0.43 kg

Speed, v = 20 m/s

Force, F = 300 N

From Newton's second law of motion, the force applied to a body is directly proportional to the rate of change of its linear momentum in the direction of the applied force..

`F = m (dv)/(dt)`

`F = m (v_(2) - v_(1))/(t_(2) - t_(1))`

F(t₂ - t₁) = m(v₂ - v₁)

FΔt = mΔv

Impulse = change in momentum

We can calculate the momentum of the soccer ball and equate it to impulse.

momentum of the soccer ball = mass × velocity

= 0.43 kg × 20 m/s

= 8.6 kgm/s

Since impulse equals change in momentum of a body, then,

The magnitude of the impulse delivered to the ball = 8.6 kgm/s or 8.6 Ns