7.Motion and momentum

Question 1

Conservation of Momentum

Answer 1

The total momentum of a system before an event must be equal to the total momentum of the system after the event, assuming no external forces act.

Question 2

Elastic Collisions

Answer 2

A collision in which the total kinetic energy of the system before the collision is equal to the total kinetic energy of the system after the collision.

Question 3

Impulse

Answer 3

The change of momentum of an object when a force acts on it. It is equal to the product of the force acting on the object and the length of time over which it acts.

Question 4

Inelastic Collisions

Answer 4

A collision in which the total kinetic energy of the system before the collision is not equal to the kinetic energy of the system after the collision.

Question 5

Linear Momentum

Answer 5

The product of an object’s mass and linear velocity.

Question 6

Newton’s First Law

Answer 6

An object will remain in its current state of motion, unless acted on by a resultant force. An object requires a resultant force to be able to accelerate.

Question 7

Newton’s Second Law

Answer 7

The sum of the forces acting on an object is equal to the rate of change of momentum of the object.

Question 8

Newton’s Third Law

Answer 8

Every action has an equal and opposite reaction. If an object exerts a force on another object, then the other object must exert a force back, that is opposite in direction and equal in magnitude.