1 / 47

How much energy is one Joule? Not much!

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. http://dspt.club.fr/PortraitJoule.jpg. How much energy is one Joule?

cooper
Download Presentation

How much energy is one Joule? Not much!

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 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 http://dspt.club.fr/PortraitJoule.jpg • 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

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

  3. Chemical Energy • Type of potential energy

  4. Electrical Energy

  5. Electromagnetic Energy

  6. Nuclear Energy

  7. Radiant or Light Energy • Solar energy

  8. Light Energy

  9. Sound Energy

  10. Thermal Energy

  11. Mechanical Energy Potential + Kinetic = Mechanical

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

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

  14. KINETIC ENERGY Energy of Motion

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

  16. 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

  17. Chemical Potential Energy  Electrical Energy  Light Energy

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

  19. Sound energy  electrical energy  sound energy

  20. Chemical potential energy  heat and kinetic energy

  21. Electrical energy  heat and light energy

  22. Electrical energy  light and sound energy

  23. Chemical potential energy  light and heat energy

  24. Electrical energy may power a light bulb and be converted to lightenergy. • The light energy also produces heatenergy.

  25. 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)

  26. The two most common energy conversions are: • Potentialenergy changing into kinetic energy. • Kinetic energy changing into potentialenergy.

  27. Thermal Energy

  28. Heat Transfer

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

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

  31. 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.

  32. 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.

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

  34. 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.

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

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

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

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

  39. 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

  40. 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

More Related