4. Momentum

Two-dimensional Collisions — Quiz

Test your understanding of two-dimensional collisions with 5 practice questions.

Practice Questions

Question 1

Two equal-mass objects collide in two dimensions. Object 1 is initially moving at $5 \, \text{m/s}$ along the x-axis, and object 2 is at rest. After the collision, object 1 moves off at $3 \, \text{m/s}$ at $30^\circ$ above the x-axis. What is the speed of object 2 after the collision?

Question 2

A $4 \, \text{kg}$ object moving at $(6 \, \text{m/s}, 0)$ collides with a $2 \, \text{kg}$ object moving at $(0, 3 \, \text{m/s})$. If the collision is perfectly inelastic, what is the magnitude of the final velocity of the combined mass?

Question 3

Two disks collide on a frictionless surface. Disk A has mass $1 \, \text{kg}$ and is moving at $4 \, \text{m/s}$ along the x-axis. Disk B has mass $2 \, \text{kg}$ and is initially at rest. After the collision, disk A moves at $2 \, \text{m/s}$ at $90^\circ$ (along the y-axis). What is the x-component of disk B’s velocity after the collision?

Question 4

A $3 \, \text{kg}$ ball is moving at $(2 \, \text{m/s}, 4 \, \text{m/s})$. It collides elastically with a $1 \, \text{kg}$ ball at rest. After the collision, the $1 \, \text{kg}$ ball moves at angle $45^\circ$ above the x-axis. What is the speed of the $1 \, \text{kg}$ ball after the collision?

Question 5

A $1 \, \text{kg}$ object moves at $(3 \, \text{m/s}, 4 \, \text{m/s})$ and collides elastically with a $3 \, \text{kg}$ object moving at $(1 \, \text{m/s}, -2 \, \text{m/s})$. What is the total momentum in the y-direction after the collision?