Science Sponge

List and describe the six main types of simple machines.

List and describe the three types of levers. Be sure to explain where the load and the fulcrum would be in each lever.

WELCOME BACK!!!!!

Science Sponge

What is the formula for mechanical energy?

What is the kinetic energy of a 2,000 kg bus that is moving at 30 m/s?

What is the gravitational potential energy of a diver who weighs 600N standing on a platform that is 8m off the ground?

Science Sponge

List all forms of energy and briefly describe each.

What is an energy conversion?Give an example of one energy

conversion that you have encountered today.

Turn your sponge in

Science Sponge

Please sit with your group and be prepared to present your energy conversion along with your visual aid. Your visual aid should have the type of conversion written out on it.

Energy and Energy Resources

Physical Science

Energy and Work: Working Together

Energy is the ability to do work

There are two main types of energy

kinetic: the energy of motion

Kinetic energy depends on mass and speed.

kinetic energy= mv2

2

M:object’s mass V: object’s speed

Practice

What is the kinetic energy of a car that has a mass of 2,400 kg and is moving at 20 m/s?

What is the kinetic energy of a 4,000 kg elephant that is running at 2 m/s? at 4 m/s? How do the two kinetic energies compare with one another?

Energy and Work: Working Together

Potential energy is the energy an object has based on its position.

Gravitational potential energy is energy transferred to an object based on the object being lifted and put into a different position.

gravitational potential energy= weight x height

Gravitational potential energy is equal to the amount of work done on an object to lift it to a certain height.

Practice

What is the gravitational potential energy of a cat that weighs 40 N standing on a table that is 0.8 m above the ground?

What is the gravitational potential energy of a driver who weighs 500 N standing on a platform that is 10 m off the ground.?

Forms of Energy

MechanicalThermalChemical

ElectricalElectromagneticNuclearSound

Energy can be transferred, or

converted, from one form to

another!

Chemical Energy

Energy stored in chemical bonds of molecules. It depends on the position

and arrangement of the atoms in a compound.

FoodBattery

Nuclear Energy

Energy stored in the nucleus of an atom from fission or fusion

SunStarsNuclear

Power Plant

Mechanical Energy

Energy associated with the total motion of an object.

Mechanical Energy = PE + KE

chewingfrog dancingriding a bikemoving fan blades

Thermal EnergyTotal energy of the moving particles in a

material.Thermal energy is produced any time energy

changes form

All objects give off thermal energy

Ice cream melting gains thermal energy

Electrical Energy

Moving electrons that produce electricity.

Static ShockLighteningComputers/

TVs/RadiosLights

Electromagnetic Energy

Energy that travels in electromagnetic waves

Visible lightUV RaysMicrowaves

Sound Energy

Energy is created because of vibrating particles.

Travels in mechanical waves

Musical instruments

Vocal cords

Energy Conversions

An energy conversion is change from one form of energy to another.

Energy Conversion

Create a scenario where you may experience energy conversions.

One person in your group is responsible for creating a visual that represents your conversion.

You have fifteen minutes to complete this activity and be prepared to share with

the rest of the class.

Energy Conversions

Elastic Potential Energy

Have you ever been popped by a rubber band???

How is elastic potential energy stored and released?

What Did You Eat for Breakfast?

Chemical energy comes from the food you eat. Your body uses chemical energy to function.

What’s your favorite breakfast food?

Energy Conversions in Plants

Chemical energy in the food you eat comes from the Sun’s energy. Light energy is changed into chemical energy through photosynthesis.

It’s an endless process and energy is always going somewhere!!

Can you imagine your life without energy conversions?

Energy is Conserved Within a Closed System

A closed system is selfish, it only transfers energy amongst itself.

Volunteers???

In your own words, describe a closed system.

Energy is Conserved Within a Closed System

A closed system is a group of objects that transfer energy only to each other.

Law of Conservation of Energy

Energy cannot be created or destroyed. The total amount of energy in a closed system is always the same.

Think about all of the energy conversions involved in having a light on.

No Conversion Without Thermal Energy

Any time one form of energy is converted into another form, some of the original energy always gets converted into thermal energy.

Go back the light bulb…

Energy Resources

Do you remember renewable, and non-renewable resources from sixth grade?

These are a result of fossil fuels

There are three types: coal, petroleum (crude oil), gasoline