Question

A soccer ball of mass 450 grams is initially moving horizontally east at 16 m/s. You kick it so that it moves horizontally north at 17 m/s. The collision lasts 0.05 s. Find the magnitude and direction of the average force you apply to the ball.

Answer 1

The force applied is 9 N

Explanation:

The force acting in the object is equal to the rate of change of momentum.

The initial momentum of ball is  = mass x velocity = 0.45 x 16 = 7.2 kg- ms⁻¹

The final momentum is = 0.45 x 17 = 7.65 kg - ms⁻¹

The change in momentum = 7.65 - 7.2 = 0.45 kg - ms⁻¹

Thus the force = $\frac{0.45}{0.05}$ = 9 N