1. Forces in Motion
Part II

2. First Law of energy (thermodynamics)
All energy is either kinetic or potential.
Copyright © 2010 Ryan P. Murphy

3. First Law of Energy (thermodynamics)
All energy is either kinetic or potential.
Copyright © 2010 Ryan P. Murphy

4. First Law of Energy (thermodynamics)
All energy is either kinetic or potential.
Copyright © 2010 Ryan P. Murphy

5. Potential Energy: (PE) The energy stored by an object as a result of its position.
Copyright © 2010 Ryan P. Murphy

8. Potential Enegy (PE) Kinetic Energy (KE)

9. Potential Enegy (PE) Kinetic Energy (KE)

10. Potential Enegy (PE) Kinetic Energy (KE)

12. Kinetic Energy is the energy of motion.
Potential Energy is the energy of position. Objects that are elevated have a high potential energy.
Kinetic Energy is the energy of motion.
Copyright © 2010 Ryan P. Murphy

14. Potential Energy
Potential

16. Kinetic Energy

17. Potential Energy
Kinetic Energy

18. Potential Energy
Potential Energy
Kinetic Energy

19. Potential Energy
Kinetic Energy
Potential Energy
Kinetic Energy

22. Copyright © 2010 Ryan P. Murphy

23. Kinetic
Copyright © 2010 Ryan P. Murphy

24. Kinetic
Potential
Copyright © 2010 Ryan P. Murphy

25. Kinetic
Potential
Potential
Copyright © 2010 Ryan P. Murphy

26. Kinetic
Potential
Kinetic
Potential
Copyright © 2010 Ryan P. Murphy

27. Activity! PE – KE Skateboarder Simulator Search Phet Skate Board Demo.
Download program (Free) -
Copyright © 2010 Ryan P. Murphy

28. g = gravitational acceleration of the earth (9.8 m/sec2)
PE = mgh
PE = Energy (in Joules)
m = mass (in kilograms)
g = gravitational acceleration of the earth (9.8 m/sec2)
h = height above Earth's surface (in meters)
Copyright © 2010 Ryan P. Murphy

29. Find the PE in Joules? PE=mgh
Calculate the potential energy for a 2 kg basketball dropping from a height of 3.5 meters with a velocity of 9.8 m / sec2.
Find the PE in Joules? PE=mgh
Copyright © 2010 Ryan P. Murphy

30. PE = mgh m = 2 kg g = 9.8 m/sec2 h = 3.5 m
PE = (2 kg ) (9.8 m/sec) (3.5 m)
PE = 68.6 Joules
Copyright © 2010 Ryan P. Murphy

31. Calculate the potential energy of a shot put dropping from a height of 6 meters weighing 5.44 kg with a velocity of 9.8 m/sec.
Find the PE in Joules?
Copyright © 2010 Ryan P. Murphy

32. PE = mgh m = 5.44 kg g = 9.8 s2 h = 6 m PE = (5.44) (9.8) (6) PE =
Copyright © 2010 Ryan P. Murphy

33. Calculate the potential energy for a 2500 kg satellite orbiting at an altitude of 1, 500, 000 meters above the surface of the earth if it is traveling with a velocity of 9.8 m/sec. Find PE in Joules?
Assume we are using the earth gravity constant.

34. PE = mgh m = 2500 kg g = 9.8 m/sec2 h = 1500000m
Copyright © 2010 Ryan P. Murphy

35. PE = mgh m = 2500 kg g = 9.8 m/sec2 h = 1500000m
PE = (2500 kg) (9.8 m/sec2) ( m)
Copyright © 2010 Ryan P. Murphy

36. PE = mgh m = 2500 kg g = 9.8 m/sec2 h = 1500000m
PE = (2500 kg) (9.8 m/sec2) ( m)
PE = ?
Copyright © 2010 Ryan P. Murphy

37. Can you put it into scientific notation?
Or PE = 36,750,000,000 Joules
Can you put it into scientific notation?
Copyright © 2010 Ryan P. Murphy

38. Can you put it into scientific notation?
Or PE = 3.6,750,000,000 Joules
Can you put it into scientific notation? 10
Copyright © 2010 Ryan P. Murphy

39. PE = 3.675 x 1010 Joules Or PE = 3.6,750,000,000 Joules
Can you put it into scientific notation? 10
PE = x 1010 Joules
Copyright © 2010 Ryan P. Murphy

40. The energy that matter has because of its motion and mass.
Kinetic energy
The energy that matter has because of its motion and mass.
Where m = mass of object (kg).
v = speed of object.
KE = Energy in Joules.
Copyright © 2010 Ryan P. Murphy

41. Kinetic Energy
Copyright © 2010 Ryan P. Murphy

42. Kinetic Energy
Copyright © 2010 Ryan P. Murphy

43. Kinetic energy is also the flow of electrons or charged particles called electrical energy.
Copyright © 2010 Ryan P. Murphy

44. Amount of KE depends on both the objects mass and its velocity (speed).
Copyright © 2010 Ryan P. Murphy

45. Don’t forget your order of operations. PEMDAS
For KE, you must do exponents (E) before multiplying (M).
Copyright © 2010 Ryan P. Murphy

46. What is the kinetic energy of a
What is the kinetic energy of a .142 kilogram baseball traveling at 45 meters per second?
m = .142 kg
v = 45 m/s
Copyright © 2010 Ryan P. Murphy

47. KE = 0.5 times .142 kg times (45)2 Joules
KE = .071 kg times 2,025 Joules
KE = Joules
Copyright © 2010 Ryan P. Murphy

48. When you lift an object, chemical energy (a form of potential energy) stored in the chemicals obtained from your digested food is converted into the mechanical energy (kinetic). Which is then used to move your body. Heat is released.
Copyright © 2010 Ryan P. Murphy