Energy

S8P2: Students will be familiar with the forms and transformation of energy.

Questions to think about!

1. What’s the difference between a moving marble and one at rest?

2. How can a marble acquire energy- the ability to cause change?

What is energy?

• This is the ability to cause change.

• Types of energy: kinetic, potential, thermal, chemical, radiant, electrical, and nuclear.

• Everything has energy, but you do not notice it until a change has occurred.

What is kinetic energy?

• This is the energy an object has due to its motion.

• If an object is not moving, it does not have kinetic energy.

• A soccer ball has kinetic energy when it rolls on the ground.

How is kinetic energy applied to speed?

• If we kick the soccer ball harder it speeds up.

• When the fast soccer ball hits the net the net moves faster.

How is kinetic energy applied to mass?

• Lets say we roll a volley ball down the road to hit some bowling pins.

• At the same time we roll a bowling ball at the same speed, which one will knock down more pins?

• If you said the bowling ball you are correct.

• This is because the volley ball has less mass.

What is potential energy?

• This is the energy stored in an object because of its position.

• A cup sitting on a counter has potential energy.

• If the cup is pushed over it changes from potential to kinetic.

• The more mass the more potential energy.

What is thermal energy?

• This is energy that increases when the temperature increases.

• Lets say we are inside a house, during the summer, that is very cool, then we walk outside. What happens?

• As the temperature increases outside our thermal energy increases.

What is chemical energy?

• This is the energy stored in chemical bonds.

• Flames of a candle is the result of chemical energy stored in the wax.

• When the wax burns it is changed from chemical energy to thermal energy.

What is radiant energy?

• This is the energy carried by light.

• The coils on a stove burner produces radiant energy when heated.

• To heat the metal coils another type of energy is used, electrical energy.

What is electrical energy?

• This is the energy that is carried by an electric current.

• A cell phone uses electrical energy.

• Basically anything that has to do with electricity uses electrical energy.

What is nuclear energy?

• This is energy contained in atomic nuclei.

• To release nuclear energy, is a difficult process.

• One of the first major usage of the nuclear energy is the atomic bomb.

The Atomic Bomb

The atomic bomb was created by Albert Einstein and many others. At the

beginning of WWII Einstein sent a letter to President Roosevelt, which begin the

making of nuclear bombs in the United States. These bombs use a major amount

of nuclear energy.

What is The Law of Conservation of Energy?

• States that energy is never created or destroyed, just like the Law of Conservation of Matter (matter is never created or destroyed, just changes form.)

• The only change is the form in which the energy appears.

Example

When a biker goes up a tall hill, energy changes. When he gets to the summit, all of his original energy is still around. Some of the energy is in the form of potential energy, which he will use as he coasts down the hill. Some of the energy has changed to thermal energy by the friction of the bike. The chemical energy in the biker

has changed to thermal energy, this is when he is hot. No energy is missing from the biker.

“No matter what you are doing you have energy. It can be potential, kinetic,

thermal, chemical, and radiant.”

John Dalton

Credits

• CRCT Coach Book• 8th grade Science book• Google pages• http://electron9.phys.utk.edu/phys136d/modules/

m8/images/gen.gif• http://www.astrosciences.info/Ergodynamics_file

s/image001.gif• http://www.mhhe.com/physsci/chemistry/chang7/

esp/folder_structure/en/m1/s1/assets/images/enm1s1_1_1.jpg

• http://www.mathtrain.com/mathtrain/file.php/1/iconsfrontpage/basketball.gif

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