Energy!

What is energy?

• Energy is the ability to cause change• When an object has energy, it can make things

happen or do work

Kinetic Energy

• Kinetic energy is the energy an object has due to its motion or movement

• If an object isn’t moving, it doesn’t have any kinetic energy

• For example, when you go bowling, the bowling ball has lots of kinetic energy as it rolls down the lane

Kinetic Energy and Speed

• The faster something moves, the more kinetic energy it has

• For example, if a professional baseball pitcher throws a baseball, it will have a lot more kinetic energy than if Ms. Alison throws it.

• Ms. Alison is not very good at baseball

Kinetic Energy and Mass

• The more mass an object has, the more kinetic energy it has

• For example, a rolling bowling ball will have a greater kinetic energy than a volleyball rolled at the same exact speed. That’s because the bowling ball has more mass than the volleyball. Lower mass

• Higher mass

Potential Energy• Potential energy is the stored energy an object

has because of its position• For example, a roller coaster has a lot of

potential energy when it reaches the top of the ride. That’s because of the position it’s in (high up, far away from ground level)

• The higher up an object is, the more potential energy it has.

• Also, the more mass an object has, the more potential energy it has.

• For example, a huge truck at the top of a hill will have more potential energy than a bicycle on top of the hill. That’s because the truck has more mass than the bicycle.

• Let’s see if you’ve understood the past couple of lessons!

• A soccer ball rolling across the field is an example of…

Kinetic energy

• A book sitting on top of a bookshelf is an example of…

Potential energy

• Which would have more kinetic energy?

A) A football thrown at 5 miles per hourB) A football thrown at 25 miles per hour

Answer: B

Pick the item that would have more kinetic and potential energy:

A) A dictionary falling out of a third floor window

B) An empty crayon box falling out of a third floor window

Answer: A

When would our science text book have more potential energy?

A) When it is on top of a table that is three feet high

B) When it is on top of a bookshelf that is 8 feet high

Answer: B

Bonus question:

• When will the potential energy of the football below change into kinetic energy?

Answer: Once the football is thrown and starts moving.