2. What is energy? Energy is the ability to do work
The unit of energy is the Joule, named after James Prescott Joule
This is also the unit of work, since energy and work are manifestations of the same thing
How much energy is one Joule?
Not much!
One Joule is the amount of energy it takes to lift a small apple to a height of one meter on the earth
Often we talk about kiloJoules, thousands of Joules

3. Energy can take many forms
Mechanical-Kinetic and Potential
Light
Electrical
Nuclear
Heat
Chemical

4. Chemical Energy
Type of potential energy

5. Electrical Energy

6. Electromagnetic Energy

7.            
Nuclear Energy

8. Radiant or Light Energy
Solar energy

9. Light Energy

10. Sound Energy

11. Thermal Energy

12. Potential + Kinetic = Mechanical
Mechanical Energy
Potential + Kinetic = Mechanical

13. This type of energy is called gravitational potential energy (abbreviated potential energy).

14. Chemical potential energy is in a fuel such as a match.

15. KINETIC ENERGY
Energy of Motion

16. Law of Conservation of Energy
Energy cannot be created nor destroyed but can converted into another form of energy.

17. Energy is conserved It may change forms but you cannot lose energy
A falling apple illustrates the relationship between potential and kinetic energy
You can convert it to a form that does not do work such as heat lost as friction
Kinetic energy increases as it falls
Potential energy decreases as it falls

18. Chemical Potential Energy  Electrical Energy  Light Energy

19. Food is a type of fuel.
Chemical potential energy  Kinetic energy

20. Sound energy  electrical energy  sound energy

21. Chemical potential energy  heat and kinetic energy

22. Electrical energy  heat and light energy

23. Electrical energy  light and sound energy

24. Chemical potential energy  light and heat energy

25. Electrical energy may power a light bulb and be converted to light energy.
The light energy also produces heat energy.

27. Einstein's equation shows this relationship.
E = Energy (Joules)
m = mass (kg)
c = speed of light (300,000 km/s or 3 x 108 m/s)

28. The two most common energy conversions are:
Potential energy changing into kinetic energy.
Kinetic energy changing into potential energy.

30.            
Thermal Energy

32. Heat Transfer

33. Conduction
Transfer of heat energy from one solid object to another when they are in direct contact.

34. Metals and other materials that readily (easily) transfer heat energy through themselves are called conductors.
Materials that transfer heat energy poorly are called insulators.

35. Convection
Process of heat transfer in fluids (liquids and gases) by means of rising and falling currents.
When a region of liquid or gas absorbs heat energy, its molecules move faster, and the distance between them increases.
The region of fluid expands as a result and becomes less dense than its surroundings.

39. Radiation Transfer of heat energy in the form of electromagnetic waves
The same kinds of energy waves transfer heat and light energy from the Sun as it radiates energy to Earth.

40. Electromagnetic waves travel through the emptiness of space.
They can also pass through many types of matter.

41. Infrared electromagnetic waves are sensed by nerves in the skin as heat.
All warm bodies radiate heat energy in the form of infrared electromagnetic waves.

42. When you sit near a fireplace, you can feel the effect of these waves warming you.

43. Toaster ovens heat and toast bread and other food products by radiation.

44. In which case would the object have more potential energy?
A bird in your hand, 1 m above the ground
The same bird on the limb of a tree, 5 m above the ground

45. In which case would the object have more potential energy?
A tennis ball, sitting on a shelf 2 m above the ground
A softball, sitting on a shelf 2 m above the ground

46. Which object has greater kinetic energy?,OR
A bowling ball, rolling at a speed of 2 m/s
A beach ball, rolling at a speed of 2 m/s

47. A golf ball, flying through the air at a speed of 15 m/s
Which object has greater kinetic energy?, OR
A golf ball, flying through the air at a speed of 10 m/s
A golf ball, flying through the air at a speed of 15 m/s