Applied Potential and Kinetic Energy

1. Applied Potential and Kinetic Energy Mr. Smet’s Scientific Studies

2. Do Now • Place your homework on the table in front of you. • Answer the following: • What is the law of conservation of energy? • Explain how a roller coaster works using the Law of Conservation of Energy.

3. Agenda • Do Now • Introduction • Homework Review • Calculations • Calculation W.S. • W.S. part 2 • Exit Slip • Closing

4. Objectives: 5.6.1 SWBAT define the Law of Conservation of Energy. 5.4.1 SWBAT explain how potential and kinetic energies are related using the conservation of energy.

5. Agenda • Do Now • Introduction • Homework Review • Calculations • Calculation W.S. • W.S. part 2 • Exit Slip • Closing

6. Question 1 • At which point does a train on this roller coaster: • Have the most gravitational potential energy? Explain your choice. • have the most kinetic energy? Explain your choice. • Have both kinetic and gravitational potential energy? Explain your choice.

7. a. The train has the most potential energy at Point B because it is the highest point on the track. • b. The train has the most kinetic energy at Point Gbecause it has converted the most energy (PE from Point B) into kinetic from the first hill. • c. The train has both kinetic energy and potential energy at points D, E and F because it has both height (PE) and speed (KE) at those points.

8. Question 2 Kinetic energy is related to the speed of an object. In which place, Point E or Point F, is the train moving faster? Explain in terms of kinetic energy.

9. Question 2 Answer The train is moving faster at point E because it has more kinetic energy there. When the train climbs the hill to point F, it has less kinetic energy and less speed.

10. Question 3 As the train travels on the track, the energy of the train changes back and forth from gravitational potential to kinetic. What other energy transformations occur as the train travels the track? Explain.

11. Question 3 Answer Some of the kinetic energy is turned into thermal energy and sound due to the friction between the train and the tracks. Friction between the air and the train also transforms some kinetic energy into wind and thermal energy.

12. Question 4 Why can’t a roller coaster go up a hill that is higher than the hill it just came down?

13. Question 4 Answer Because in order to climb a bigger hill, energy must be added to the train. The role-play pointed out that a roller coaster is at its maximum energy at the first hill. After that, no energy is put into the system and some energy is lost by heating and sound as the roller coaster travels. So there is less energy available to transform from kinetic to potential for each subsequent hill.

14. Agenda • Do Now • Introduction • Homework Review • Calculations • Calculation W.S. • W.S. part 2 • Exit Slip • Closing

15. Concept • Last week, we learned about the Conservation of Energy.

16. Concept • Last week, we learned about the Conservation of Energy. Energy cannot be lost or destroyed.

17. Total Energy • Total energy is the amount of energy an object has.

18. Total Energy • Total energy (TE) is the amount of energy an object has. • Total Energy = Potential Energy + Kinetic Energy TE = PE + KE

19. Example:

20. CFU A. PE = 7J KE = 6J B. PE = 12 J KE = 8 J B. PE = 32 J KE = 49 J

21. Determining PE or KE • If you know both Total Energy and Potential Energy/Kinetic Energy, you can find the other. • KE = TE – PE • PE = TE - KE

22. CFU A. PE = 17J KE = 6 J TE = ? B. PE = 15 J KE = ? B. PE = ? KE = 20 J

23. CFU A. PE = 6J KE = 12 J TE = ? B. PE = 11 J KE = ? B. PE = ? KE = 15 J

24. Agenda • Do Now • Introduction • Homework Review • Calculations • Calculation W.S. • W.S. part 2 • Exit Slip • Closing