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?