1. E NERGY

2. The ability to do work. Many forms Unit of measure: joule (J) Amount of force of one newton over one meter. 1J =

3. K INETIC E NERGY The energy of an object in motion Kinetic energy of an object depends on its mass and speed. Kinetic Energy = ½ mv 2 If you double the mass of an object, you double the KE If you double the speed of an object, you quadruple the KE

4. Y OU SERVE A VOLLEYBALL WITH A MASS OF 2.1 KG. T HE BALL LEAVES YOUR HAND WITH A SPEED OF 30 M / S. W HAT IS THE KINETIC ENERGY OF THE VOLLEYBALL ? KE = ½mv 2 KE = ½ * 2.1kg * (30m/s) 2 KE = ½ * 2.1kg * 900m 2 /s 2 KE = ½ * 1890kg*m 2 /s 2 KE = 945J KE = 900J

5. N OW, TRY ONE FOR YOURSELF !

6. A 50- KILOGRAM BOY AND HIS 100- KILOGRAM FATHER WENT JOGGING. B OTH RAN AT A RATE OF 5 M / SEC. W HO HAD MORE KINETIC ENERGY ? KE = ½mv 2 KE(boy) = ½ * 50kg * (5m/s) 2 KE(boy) = ½ * 50kg * 25m 2 /s 2 KE(boy) = ½ * 1250kg*m 2 /s 2 KE(boy) = 625J = 600J KE(father) = ½ * 100kg * (5m/s) 2 KE(father) = ½ * 100kg * 25m 2 /s 2 KE(father) = ½ * 2500kg*m 2 /s 2 KE(father) = 1250J = 1000J

7. P OTENTIAL E NERGY Stored energy that is a result of position or shape.

8. G RAVITATIONAL P OTENTIAL E NERGY The potential energy that is the result of an object’s height. The higher an object, the greater the PE PE = mgh m = mass h = height g = acceleration due to gravity 9.8m/s 2

9. W HAT IS THE POTENTIAL ENERGY OF A 15.0 KG CINDER BLOCK SITTING ON A PLATFORM 10.0 M HIGH ? PE = mgh PE = 15.0kg * 9.80m/s 2 * 10.0m PE = 1470 kg * m 2 /s 2 PE = 1470 J

10. G UESS WHAT ’ S NEXT ? That’s right….try one on your own!

11. WHAT IS THE POTENTIAL ENERGY OF A 80.0 KG DIVER STANDING ON A PLATFORM 10.0 M ABOVE A POOL ? PE = mgh PE = 80.0kg * 9.80m/s 2 * 10.0m PE = 7840kg * m 2 /s 2 PE = 7840J

12. E LASTIC P OTENTIAL E NERGY The potential energy of an object that is stretched or compressed.

13. O THER FORMS OF ENERGY

14. M ECHANICAL E NERGY The energy associated with the motion and position of everyday objects The sum of an object’s potential and kinetic energy.

15. T HERMAL E NERGY The total kinetic and potential energy contained in the atoms of an object. The faster the atoms in an object move, the greater its thermal energy.

16. C HEMICAL E NERGY The energy stored in the chemical bonds of a substance. Hydrocarbons Exothermic reactions

17. E LECTRICAL E NERGY The energy associated with electrical charges. Work performed by the transfer of electrons from one atom to another.

18. E LECTROMAGNETIC E NERGY Energy that travels in waves. Visible light X-rays

19. N UCLEAR E NERGY Energy stored in the nucleus of an atom Large amounts of potential energy Fission The energy released when the nucleus of an atom is split apart. Fusion The energy released when two small nuclei fuse together to make one large nucleus.

20. E NERGY C ONVERSION Energy can be converted from one form to another Digestion of food Chemical energy → mechanical energy Nuclear power plant Nuclear energy → Electrical energy Light bulb Electrical energy → Electromechanical energy

21. W ITH YOUR PARTNER, BRAINSTORM AS MANY WAYS IN WHICH ENERGY IS CONVERTED FROM ONE FORM TO ANOTHER AS YOU CAN THINK OF.

22. L AW OF CONSERVATION OF E NERGY Energy cannot be created or destroyed.

23. E NERGY AND M ASS Albert Einstein E = mc 2 Where c=speed of light, 3.0x10 8 m/s If 1 gram of matter were converted entirely to energy: E = 1x10 -3 kg x 3.0x10 8 x 3.0x10 8 = 9x10 13 J