[PHY102] Impulse and Momentum

Impulse

• Product of average force and the time interval during which the force acts

• A vector quantity

  • Has the same direction as the average force

Average Force

• Impulse is a vector quantity

• Has the same direction as the ____ _____

Formula of Impulse

 Newton x Seconds (N X S)

SI Unit of Impulse

Linear Momentum

• Quantity of motion of an object.

• Product of the object’s mass times its velocity.

• A vector quantity

  • Has the same direction as the velocity

Velocity

• Linear Momentum is a vector quantity.

• Has the same direction as the ____

Formula of Linear Momentum

Impulse-Momentum Theorem

• When a net force acts on an object, the impulse of this force is equal to the change in the momentum of the object.

Formula of Impulse-Momentum Theorem

Expanded Formula of Impulse-Momentum Theorem

Small

• The average momentum for a longer elapsed time has a smaller/bigger impact force.

Inverse Relationship

• Relationship between average momentum and elapsed time.

Velocity

• The variable that needed to be changed to change the momentum.

Progress

What is the meaning of the p in the momentum formula which states:

• p = mv

Principle of Linear Momentum

• Total linear momentum of an isolated system is constant or conserved.

Isolated System

• One for which the sum of the average external forces acting on the system is 0

Isolated System

Occurs when two objects wanted to be at the same place and time.

Collisions in One Dimension

• When two objects collide (assume in an isolated system), total linear momentum is conserved.

Formula for Principle of Linear Momentum

1. Elastic

2. Inelastic

2 types of Collisions in one dimension

Elastic Collision

• Total KE of the system after collision is equal to the total kinetic energy before the collision

• KE is conserved

Conserved

• In Elastic Collision, KE is _____?

Inelastic Collision

• KE is not conserved

• Objects stick together after colliding

Completely/Perfectly Inelastic Collision

• Also known as Inelastic Collision

• The energy is transformed into a new form of energy.

Internal Forces

• Forces that objects within the system exert on each other.

External Forces

• Forces exerted on objects by agents external to the system.