Collisions, explosions and impulse test questions

1

A fairground uses bumper cars of mass \(80kg\). Donnie has a mass of \(70kg\) and is driving his car at \(+ 0.9m{s^{ - 1}}\) to the right directly at Anna. Anna has a mass of \(50kg\) but her car is moving to the left with a velocity of \(1.2m{s^{ - 1}}\). After the inevitable head-on collision, Anna's car comes to a stop.

Two bumper cars driving towards each other in an imminent collision.

What is the total momentum before the collision?

2

A fairground uses bumper cars of mass \(80kg\). Donnie has a mass of \(70kg\) and is driving his car at \(+ 0.9m{s^{ - 1}}\) to the right directly at Anna. Anna has a mass of \(50kg\) but her car is moving to the left with a velocity of \(1.2m{s^{ - 1}}\). After the inevitable head-on collision, Anna's car comes to a stop.

Two bumper cars driving towards each other in an imminent collision.

What is Donnie's velocity after the collision?

3

A fairground uses bumper cars of mass \(80kg\). Donnie has a mass of \(70kg\) and is driving his car at \(+ 0.9m{s^{ - 1}}\) to the right directly at Anna. Anna has a mass of \(50kg\) but her car is moving to the left with a velocity of \(1.2m{s^{ - 1}}\). After the inevitable head-on collision, Anna's car comes to a stop.

Two bumper cars driving towards each other in an imminent collision.

Calculate the total kinetic energy before the collision.

4

A fairground uses bumper cars of mass \(80kg\). Donnie has a mass of \(70kg\) and is driving his car at \(+ 0.9m{s^{ - 1}}\) to the right directly at Anna. Anna has a mass of \(50kg\) but her car is moving to the left with a velocity of \(1.2m{s^{ - 1}}\). After the inevitable head-on collision, Anna's car comes to a stop.

Two bumper cars driving towards each other in an imminent collision.

The collision is inelastic. How does the kinetic energy after the collision compare to the kinetic energy before the collision?

5

A sports scientist is measuring the forces on a tennis racquet using the time of contact between the ball and the racquet. The tennis ball has a mass of \(57g\) and hits the stationary racquet with a velocity of \(- 19m{s^{ - 1}}\) (right to left), it rebounds at \(17m{s^{ - 1}}\). The time of contact was measured as \(0.040s\).

A tennis ball weighing 57g travels towards the tennis racquet at a velocity of -19 metres per second. The ball rebounds at a velocity of +17 metres per second.

What is the change in momentum of the tennis ball?

6

A sports scientist is measuring the forces on a tennis racquet using the time of contact between the ball and the racquet. The tennis ball has a mass of \(57g\) and hits the stationary racquet with a velocity of \(- 19m{s^{ - 1}}\) (right to left), it rebounds at \(17m{s^{ - 1}}\). The time of contact was measured as \(0.040s\).

A tennis ball weighing 57g travels towards the tennis racquet at a velocity of -19 metres per second. The ball rebounds at a velocity of +17 metres per second.

Calculate the impulse of the racquet on the ball.

7

A sports scientist is measuring the forces on a tennis racquet using the time of contact between the ball and the racquet. The tennis ball has a mass of \(57g\) and hits the stationary racquet with a velocity of \(- 19m{s^{ - 1}}\) (right to left), it rebounds at \(17m{s^{ - 1}}\). The time of contact was measured as \(0.040s\).

A tennis ball weighing 57g travels towards the tennis racquet at a velocity of -19 metres per second. The ball rebounds at a velocity of +17 metres per second.

What is the average force on the ball from the racquet?

8

A sports scientist is measuring the forces on a tennis racquet using the time of contact between the ball and the racquet.

The tennis ball has a mass of \(57g\) and hits the stationary racquet with a velocity of \(- 19m{s^{ - 1}}\) (right to left), it rebounds at \(17m{s^{ - 1}}\).

Graph of peak force exerted by racquet on ball. Y-axis = Force (N) X-axis = Contact time (ms). Peak force at 0.02 ms. Zero force at 0.04 ms.

The time of contact was measured as \(0.040s\).

The scientist knows that the force varies with contact time as shown in the graph.

What is the peak force exerted by the racquet on the ball?