Momentum

In sports when player has a lot of momentum, what we mean, that it will be hard to stop them.

In Physics momentum refers to the quantity of motion that an object has.

A sports team that is on the move has the momentum. If an object is in motion (on the move) then it has momentum.

What is Momentum?

Momentum can simply be defined as mass in motion

Since every object has mass, if it is in motion it has momentum

How do we measure momentum?

p=mv

What is Momentum

In the above equation p stands for momentum, m stands for mass, and v stands for velocity.

The amount of momentum something has is dependant upon two variables; mass and velocity

Mass = how much stuff is moving Velocity = how fast the stuff is moving

p=mv The Momentum Equation

Remember, in this equation both mass and velocity are directly proportional to momentum!

Directly proportional means if mass or velocity increase our momentum will increase by the same factor.

The units of measure we use for momentum are simple; we use kg(m)/s

p=mv The Momentum Equation

It is important to understand and remember that momentum is a vector quantity.

Vector quantities as you should recall have both magnitude and direction.

We get our magnitude from the equation p=mv

We get our direction from the direction the object is moving

Momentum is a Vector Quantity

The Quarterback is traveling north towards the end zone at 2m/s and has a mass of 100kg. What is his momentum?

Use your colored pencils and the equation p=mv to solve!

Lets try it!

The Quarterback is traveling north towards the end zone at 2m/s and has a mass of 100kg. What is his momentum?

Mass of the quarter back = 100kg Velocity of the quarter back = 2m/s Momentum=mass(velocity) ?=100kg(2m/s) 200kg(m)/s northward

Answer!

If something has a large mass it is going to have a lot of momentum.

If something has a lot of velocity it will also have a lot of momentum because both velocity and mass are directly proportional to an objects momentum.

Review of Momentum

What is an objects momentum if that object is at rest?

In this photo the car is at rest; which means it is not moving and has a velocity of 0m/s

Momentum MUST be 0kg(m)/s as well.

Objects at rest

1. Determine the momentum of a ...

◦ a. 60-kg halfback moving eastward at 9 m/s.

◦ b. 1000-kg car moving northward at 20 m/s.

◦ c. 40-kg freshman moving southward at 2 m/s.

Try on your own!