2.7.1 Understanding Impulse

An object of mass $50 \mathrm{~kg}$ accelerates from a velocity of $2.0 \mathrm{~m} / \mathrm{s}$ to a velocity of $10 \mathrm{~m} / \mathrm{s}$ in the same direction.
What is the impulse provided to cause this acceleration?

A tennis ball of mass $0.060 \mathrm{~kg}$ travels horizontally at a speed of $25 \mathrm{~m} / \mathrm{s}$. The ball hits a tennis racket and rebounds horizontally at a speed of $40 \mathrm{~m} / \mathrm{s}$.
The ball is in contact with the racket for $50 \mathrm{~ms}$. What force does the racket exert on the ball?

An object has a mass of $60 \mathrm{~kg}$. It decelerates from $50 \mathrm{~m} / \mathrm{s}$ to $20 \mathrm{~m} / \mathrm{s}$ when a resultant force of $300 \mathrm{~N}$ acts on it. For how long does the force act?

A resultant force of $4.0 \mathrm{~N}$ acts on an object of mass $0.50 \mathrm{~kg}$ for $3.0$ seconds. What is the change in velocity caused by this force?

A moving ball with a momentum of $25 \mathrm{~kg} \mathrm{~m} / \mathrm{s}$ collides head-on with a wall.

It rebounds from the wall with the same speed but in the opposite direction. The time of collision is $50 \mathrm{~ms}$.
What is the average force exerted on the wall by the ball during the collision?

A ball of mass $0.50 \mathrm{~kg}$ falls and hits the floor at $10 \mathrm{~m} / \mathrm{s}$. It rebounds at speed $8.0 \mathrm{~m} / \mathrm{s}$, as shown.
The collision between the ball and the floor lasts for $0.50 \mathrm{~s}$. What is the average force acting on the ball during the collision?

A ball is at rest on the ground. A boy kicks the ball. The boy’s boot is in contact with the ball for $0.040 \mathrm{~s}$.
The average force on the ball is $200 \mathrm{~N}$. The ball leaves the boy’s boot with a speed of $20 \mathrm{~m} / \mathrm{s}$.
Which row gives the impulse of the boot on the ball and the average acceleration of the ball?

$$\begin{array}{|c|c|c|} \hline & \frac{\text { impulse on ball }}{\mathrm{Ns}} & \frac{\text { average acceleration of ball }}{\mathrm{m} / \mathrm{s}^2} \\ \hline \text { A } & 8 & 0.8 \\ \text { B } & 8 & 500 \\ \text { C } & 5000 & 0.8 \\ \text { D } & 5000 & 500 \\ \hline \end{array}$$

The momentum of a body is changed by a force acting on it for a period of time. Which action increases the change in momentum?

An object of mass $1.2 \mathrm{~kg}$ is moving with a velocity of $2.0 \mathrm{~m} / \mathrm{s}$ when it is acted on by a force of $4.0 \mathrm{~N}$. The velocity of the object increases to $5.0 \mathrm{~m} / \mathrm{s}$. For what period of time does the force act on the object?