1. Energy: Forms and Changes
Chapter 16

2. Energy:
is the ability to do work
is measured in joules (J)

3. Objects can gain energy when work is done on them

4. There are five different forms of energy
Mechanical
Heat
Chemical
Electromagnetic
Nuclear

5. Mechanical
Energy of motion

6. Heat Internal motion of atoms
The greater the motion, the more heat the object contains

7. Heat Energy

8. Chemical Energy found in the bonds of atoms
Released when those bonds are broken

9. Chemical Energy

10. Moving electrical charge
Electromagnetic
Moving electrical charge

11. Electromagnetic Energy

12. Nucleus in atom break apart (fission)
Nuclear or
nuclei join (fusion)

13. Nuclear Energy

14. Energy can be classified as either kinetic or potential
kinetic is the energy of movement
potential is the energy of position or shape

15. Energy of position or shape
Energy is stored for later use

16. If potential energy depends upon height (gravity), then formula is: GPE = weight X height (weight = mass X gravity constant)
If a 10 N rock is sitting on a wall 10 meters high, what is its potential energy?

17. Kinetic Energy (KE) = mass X velocity2
Which affects KE the most – mass or velocity?

18. Kinetic or Potential Energy

19. Energy Conversions
Like matter, energy is neither created nor destroyed by ordinary means; however, it can be changed from one form to another.
All forms of energy can be converted to other forms.

20. Potential to Kinetic Conversions

21. At this position, is there kinetic and/or potential energy?

22. How many different ways can the sun’s energy be converted?
How many different conversions of energy occur when one uses a hairdryer at home.

23. Energy Conversion

24. Part of Einstein’s theory of relativity deals with the concept that mass and energy are directly related.
Einstein 1905

25. He stated that mass and energy can be converted into each other
He stated that mass and energy can be converted into each other. If matter is destroyed, it becomes energy and energy can become mass.
This is the theory of how the sun creates so much energy – some mass is destroyed causing much energy to be created.

26. E = mc2

27. How does energy relate to:
speed?
more energy, more speed
momentum?
energy is transferred
force?
energy needed to change motion
power?
rate of energy consumed
work?
energy is conserved (input vs output)