5.2.1 Elastic Collisions in One Dimension

Question 1

Elastic Collisions in One Dimension

Answer 1

• Elastic collisions are collisions in which kinetic energy is conserved, and inelastic collisions are collisions in which kinetic energy is not conserved.
• For elastic collisions in one dimension, solve the equations for conservation of momentum and conservation of energy to predict the final state of the system. Assuming , the solutions are an

Question 2

A 1,500 kg car traveling east at 10 m / s collides with a 1,000 kg truck traveling west at 20 m / s. The car and the truck stick together after the collision. Which of the following is their common velocity after the collision?

Answer 2

2 m / s; west

Question 3

Consider an isolated system consisting of two objects. In an elastic collision between the two objects, which of the following statements is incorrect?

Answer 3

The kinetic energy of each object remains unchanged during the collision.

Question 4

A 50 kg boy runs at a speed of 6.0 m / s and jumps into a cart, which was at rest on a frictionless surface. If the speed of the cart with the boy in it is 2.0 m / s, which of the following is the mass of the cart?

Answer 4

100 kg

Question 5

A 5.0 kg mass that is at rest receives an impulse of 10 N • s. Following this impulse, the _____________.

Answer 5

change in momentum of the mass is 10 kg m / s

Question 6

In a two-body collision, total momentum will be conserved if, and only if, ___________.

Answer 6

the net external force acting on the two-body system is zero

Question 7

A 4.0 kg ball moves to the right with a speed of 3.0 m / s. It suffers an elastic collision with another ball having a mass of 6.0 kg moving to the left at 2.0 m / s. Which of the following is the total kinetic energy after the collision?

Answer 7

30 J

Question 8

A collision is elastic if __________.

Answer 8

the total kinetic energy is conserved