1. Unit III Energy Physical Science Forms of Energy

2. Energy is the ability to do work Measured in Joules (J) just like work All matter has energy

3. General Forms of Energy 1. Kinetic Energy: KE = ½ m v 2 The energy of motion. Anything that is moving has kinetic energy. Do these people have KE?

4. 2.Potential Energy: PE = mgh Energy that is stored or is not being used yet Do these things have PE?

5. How to change KE Change the mass or velocity of an object If velocity is doubled, KE is quadrupled

6. Types of PE Gravitational PE: depends on how high off the ground an object is. * the greater the height and mass the object has the more Gravitational PE it has Elastic PE: the ability of an object to rebound to its original shape or size (we don’t have to calculate this one)

7. Types of Energy 1.Mechanical: Energy of everyday objects (anything with mass and volume)

8. 2. Chemical Energy: energy that is stored in chemical bonds

9. 3.Electromagnetic Energy: energy that is related to charge and magnetic poles

10. 4.Thermal Energy: energy that is based on the internal motion of particles in an object (Heat and temperature)

11. 5. Nuclear Energy: energy that is contained in the nucleus. Released when strong and weak nuclear forces are overcome

12. Energy Conversion When energy is transferred between one type and another. Example: burning gasoline transfers chemical potential into thermal energy

13. Energy Conversion In a perfect situation, the total energy in a conversion is conserved. Total Energy is all of the PE and KE of a situation added together. KE 1 + PE 1 = KE 2 + PE 2

14. KE and Friction Friction slows an object down therefore it reduces the amount of kinetic energy Increases the amount of Thermal Energy

15. Practice Problem 1. A 0.15 kg ball is thrown into the air and rises to a height of 20.0 m. How much kinetic energy did the ball have initially?

16. 2. A 1.25 kg steel ball with a kinetic energy of 0.25 J rolls along a horizontal track. How high up an inclined track will the ball roll if friction can be ignored?

17. Renewable vs. Non Renewable Renewable: forms of energy that can reproduce fast enough with use Nonrenewable: energy that cannot reproduce itself