WORD SEARCH

1. WORD SEARCH How many forms of energy can you find? Can you think of an example for each type of energy?

2. Different types of energy There are many different types of energy: • thermal • light • sound • elastic • gravitational • kinetic • electrical • chemical • nuclear elastic gravitational kinetic chemical

3. Gravitational Potential Energyand Kinetic Energy By the end of the lesson you should be able to: Explain what kinetic energy depends on Calculate the kinetic energy of moving objects Explain what gravitational potential depends on Calculate the gravitational potential energy of objects

4. When you lift an object up, energy is transferred from your muscles in to gravitational potential energy of the object. Gravitational potential energy (GPE) is energy stored in an object because of its position in the earths gravitational field.

5. Which books have GPE? • Which book has the most GPE? • Which book has the least GPE?

6. What would happen to the GPE of book C, if you moved it to the higher shelf? • Where did this energy come from? • What would happen to the GPE of book B, if you moved it to the lower shelf?

7. What do you think GPE would depend on? The amount of gravitational potential energy an object on Earth has depends on its: • Mass • Height above the ground

8. Gravitational potential energy is the energy stored in an object because of its height above ground. Gravitational potential energy = _____x gravitational field strength x _____ or Ep= m x g x h Ep: the change in gravitational potential energy (unit:___) m: the ____ (unit:______) g: is the gravitational field strength (unit:_____) h:is the change in ______ (unit:______)

9. Gravitational potential energy is the energy stored in an object because of its height above ground. Gravitational potential energy = Mass x gravitational field strength x Height or Ep= m x g x h Ep: the change in gravitational potential energy (unit: J) m:the mass (unit: kg) g: is the gravitational field strength (unit: N/kg or m/s2) h:is the change in height (unit: m)

10. change in GPE = mass x change in height x gravitational field strength (10 N/kg) Calculate change in GPE, when a 1000kg aeroplane, takes off up to a height of 500m.

11. Example Woof! (help!) A dog of mass 12 kg falls from an aeroplane at a height of 3.4 km. How much gravitational energy does the dog have as it leaves the aeroplane? (The dog has a parachute and is not harmed during this physics experiment)

12. Example On earth g = 10 m/s2 Mass of dog = 12 kg Height = 3.4 km = 3400 m

13. Example On earth g = 10 m/s2 Mass of dog = 12 kg GPE of dog = mgh = 12 x 10 x 3400 = 408 000 J Height = 3.4 km = 3400 m

14. Example GPE of dog = mgh = 12 x 10 x 3400 = 408 000 J Just before the dog hits the ground, what has this GPE turned into?

15. Kinetic energy

16. Which one has the most kinetic energy? A jaguar A tortoise? or This jaguar or This jaguar The kinetic energy depends on… 1. 2.

17. Kinetic Energy Kinetic energy is the energy an object has due to its motion. It depends on two things: • Mass of the object • Speed of the object Kinetic energy (KE) =1 x mass x speed2 2 Units KE: _____ Mass: _____ Speed: ____

18. A car with a mass of 500 kg is moving at a speed of 12 m/s. How much kinetic energy does it have?

19. A car with a mass of 500 kg is moving at a speed of 12 m/s. How much kinetic energy does it have? KE= ½ x m x speed2 KE=½ x 500 x (122)= 36,000 j

20. Where is this useful? • Many theme park rides use the transfer of gravitational potential energy to kinetic energy and kinetic energy to gravitational potential energy. https://www.youtube.com/watch?v=Ehx1P4adv6I

22. Texas locomotives accident (1896)

24. http://sciencewaldegrave.weebly.com/

25. https://www.youtube.com/watch?v=8H41zbqrwVo