Question

A T-ball with a mass of 0.1 kg travels in the air at 40 m/s until it is stopped in the glove of a shortstop over a period of 0.1 s.

1. What magnitude of the impulse was imparted to the T-ball?
2. What is the average net force exerted by the ball on the glove?

Answer 1

Answer:

1. -4 Ns

2. 40 N

Explanation:

1.

Impulse : This can be defined as the product of force and time of a body. The S.I unit of impulse is Ns.

From Newton's second law of motion,

Impulse = change in momentum

I = Ft = m(v-u).

I = m(v-u).................. Equation 1

Where I = Impulse imparted to the T-ball.

Given: m = 0.1 kg, u = 40 m/s v = 0 m/s² ( stooped)

Substituting into equation 1

I = 0.1(0-40)

I = 0.1(-40)

I = - 4 Ns.

Note: The negative sign means that the impulse act against the T- ball.

2.

Force = impulse/time

F = I/t ................. Equation 2

Where F = Force, I = impulse imparted to the T- ball,  t = time.

Given: I = 4 Ns, t = 0.1 s.

Substituting into equation 2

F = 4/0.1

F = 40 N.

Hence the average net force exerted by the ball on the glove = 40 N