1. Work and Energy

2. What is WORK? Work is equal to the amount of force it takes for an object to move a distance. Formula: Work = Force X Distance W = F x D Work is measured in Joules (Newton x meters)

3. Work Example 1: Work = F X D W= 20 X 0 W= 0 J No work is done Example 2: Work = F X D W= 20 X 3 W= 60 J Work is done

4. Work Example 3: Work = F X D W= 6 X 2 W= 12 J Example 4: Work = F X D W= 3 X 4 W= 12 J

5. Energy Review Energy is the ability to do work The more energy an object has, the more work it can do Has two basic forms – Kinetic – Potential

6. Potential Energy (PE) Potential Energy - stored energy; can be released later to do work 2 types: – Elastic- stretching or compressing – Gravitational- depends on height, higher = more gravitational PE Based on an objects position and size The higher the object, the more PE The larger the mass, the more PE

7. Kinetic Energy (KE) Kinetic Energy - energy of motion Amount of KE depends on mass and velocity of the object KE increases as mass and velocity increases The faster you’re moving (more velocity), the more kinetic energy you have!

8. Roller Coaster Where is the highest gravitational PE? Where is the highest KE?

9. At which point(s) would the potential energy be equal? At which point would kinetic energy be the greatest? Pendulum

10. Bouncing Ball Where is PE the greatest? Where is KE the greatest?

11. Energy Transformation The change of energy from one form to another. Must follow the Law of Conservation of Energy: energy cannot be created or destroyed, only transformed (changed.) MR. SCENT

12. Mechanical Energy Energy of motion

13. Radiant Energy Energy of electromagnetic waves Examples: Sunlight Radio waves X-rays

14. Sound Energy Vibration of molecules in surrounding medium (usually air.)

15. Chemical Energy Comes from bonds between atoms in molecules Examples: – Gasoline burning in a car – Food we eat – Batteries

16. Electrical Energy Comes from the flow of electrons.

17. Nuclear Energy Comes from reactions between atomic nuclei. Produces HUGE amounts of energy.

18. Thermal Energy HEAT ENERGY Amount of thermal energy based on how fast particles of matter are moving.

19. Explain the energy transformation that takes place in a flashlight. chemical electrical radiant Write in journal.