Law of of Energy. Energy is NEVER created or destroyed! Energy can only be STORED or TRANFERRED.

Transcription

1 Energy!

2 What is ENERGY? Energy is the ability to do work. Everything that happens in the world uses energy! Most of we can t see energy, but it is everywhere around us!

3 Law of of Energy Energy is NEVER created or destroyed! Energy can only be STORED or TRANFERRED.

4 This car uses a lot of energy Batteries store energy! Even this sleeping puppy is using stored energy. We get our energy from FOOD!

5 Remember: ALL maoer is made up of The NEVER stop moving.

6 How is all energy divided? All Energy Energy Energy

7 Energy is The energy stored in an object. simply means the energy has the ability to do something useful later on.

8 Gravitational Potential Energy Potential energy due to an object s position. You can increase GPE by increasing height above ground. Two objects at the same height, the one with the greater mass will have more GPE. GPE also depends on mass P.E. = mass x height x gravity

9 Elastic Potential Energy Potential energy due to compression or expansion of an elastic object. Notice the ball compressing and expanding

10 Chemical Potential Energy Potential energy stored within the chemical bonds of an object. When bonds are broken, energy is released. All fuels (including gas and food) are considered chemical energy.

11 Examples of Potential Energy: A stretched rubber band.. Water at the top of a waterfall.. Yo Yo held in your hand.. A drawn Bow and Arrow

12 Remember The higher an object, the more energy. The more mass an object has, the more energy it has.

13 Which object has more energy? B A

14 ANSWER A This brick has more mass than the feather; therefore more potential energy!

15 Changing an objects height can change its energy. If I want to drop an apple from the top of one of these three things, where will be the most poten@al energy? A B C

16 ANSWER A The higher the object, the more poten@al energy!

17 Potential Energy Converted to Kinetic Energy When stored energy begins to move, the object now transfers from potential energy into kinetic energy.

18 Energy Is The energy of a moving object. "Kine@c" means movement! When stored energy is being used up, it is making things move or happen.

19 Examples of Kinetic Energy:

20 The faster the object moves, the more energy is produced. The greater the mass and speed of an object, the more energy there will be. When an object has the LEAST energy, it has the MOST energy.

21 When these objects move at the same speed, which will have more energy?

22 ANSWER The semi- truck has more mass; therefore, more kinetic energy!

23 A water boole is knocked off a desk. When does the boole have the MOST kine@c energy? A. At the top of the fall. B. In the middle of the fall. C. At the booom of the fall.

24 C. At the booom of the fall. It has the most energy when its movement and speed are greatest, which is at the booom of the fall right before it hits the ground. When an object has the LEAST energy is when it has the MOST energy.

25 Roller Coasters When does the train on this roller coaster have the MOST energy? AT THE VERY TOP! The HIGHER the train is liyed by the motor, the MORE energy is produced. At the top of the hill the train has a huge amount of poten@al energy, but it has very liole kine@c energy.

26 As the train accelerates down the hill the energy is converted into energy. There is very little potential energy at the bottom of the hill, but there is a great amount of kinetic energy.

27 When does the train on this roller coaster have the MOST energy? (When is it moving the fastest?) At the booom of the tallest hill!

28 Energy Transfer Energy TRANSFER is the passing of energy from one object to another object. Example: A cup of hot tea has thermal energy. Some of this thermal energy is transferred to the particles in cold milk, in which you put to make the coffee cooler.

29 Energy Conversion A change from one form of energy to another. Single Conversion Occur when one form of energy needs to be transformed into another to get work done. Mul@ple Conversions Occur when a series of energy transforma@ons are needed to do work. As velocity increases, kine@c energy increases, and poten@al energy decreases. As velocity decreases, kine@c energy decreases, and poten@al energy increases.