1. Energy
The Nature of Energy

2. Learning Targets KNOWLEDGE SKILL Reasoning
Know that there are different forms of energy
SKILL
Calculate the potential and kinetic energy of different objects using formulas
Reasoning
Compare and contrast potential and kinetic energy

3. Questions to Think About
What are the two basic kinds of energy? Examples?
What are some of the different forms of energy? Examples?

4. Unit of Energy = Newton-meter
What is Energy?
Work
Occurs when a force moves an object through a distance
Energy
The ability to do work or cause change
Energy is transferred when objects or organisms do work on other objects
Work = Energy Transfer
Energy is measured in JOULES (J)
Unit of Energy = Newton-meter
Also known as Joules (J)

5. Two General Kinds of Energy
Kinetic Energy
Transferred Energy
Potential Energy
Stored Energy

6. Kinetic Energy Kinetic Energy Kinetic Energy = “MOVING”
Energy in motion
Kinetic Energy = “MOVING”
Depends on MASS and VELOCITY
Energy increases as Mass increases
Energy increases as Velocity increases
Which ball you roll more forcefully?
What would you have to do to make the bowling ball move faster?

7. Calculating Kinetic Energy
The mathematical relationship between kinetic energy, mass, and velocity is written like this:
IF YOU:
Double the Mass = Double the Kinetic Energy
Double the Velocity = Quadruple the Kinetic Energy OR

8. Calculating Kinetic Energy
10-kg wagon moving at 5 m/s
10-kg wagon moving at 10 m/s
20-kg wagon moving at 5 m/s
15-kg wagon moving at 5 m/s
Questions
Which wagon has the greatest kinetic energy?
How do you increase a moving object’s kinetic energy?

9. How does each object have potential energy?
Energy that is stored and held in readiness to do work
Potential Energy = “STORED”
Elastic Potential Energy
Stretched or compressed objects
Gravitational Potential Energy
Depends on height
How does each object have potential energy?

10. Calculating Potential Energy
Gravitational Potential Energy formula when you know weight and height:
Increase WEIGHT = increase PE
Increase HEIGHT lifted = increase PE
Gravitational Potential Energy formula when you know height and mass instead of weight:
Gravitational Acceleration = 9.8 m/s/s

11. Calculating Potential Energy
Hiker climbs 40 meters up a hill and he weighs 680 Newtons
A boulder weighs 200 N is poised at the edge of a 100-meter cliff
A book has a mass of 15 kg and is ready to drop from a height of 5 meters
Questions:
How do you know what formula to use?
Which object has more potential energy?

12. Forms of Energy Energy is all around you in many different forms
Kinetic and Potential Energy have a variety of different forms
Some of the Major Forms of Energy include:
Mechanical Energy
Thermal Energy
Chemical Energy
Electrical Energy
Electromagnetic Energy
Nuclear Energy

13. Can occur either as KE or PE
Mechanical Energy
Can occur either as KE or PE
PLYMOUTH
Mechanical Energy
Associated with the motion or position of an object

14. Thermal Energy Thermal Energy
Total energy of the particles in an object
When thermal energy of an object increases, its particles move faster, making it feel warm to the touch
Can occur either as PE and KE

15. Chemical Energy Chemical Energy
Potential energy stored in chemical bonds that hold chemical compounds together
Stored in chocolate, wood, and wax
Stored in foods you eat and cells in your body

16. Electrical Energy Electrical Energy
Moving electric charges that produce electricity

17. Electromagnetic Energy
Travels in waves
Waves have electrical and magnetic properties

18. Nuclear Energy Nuclear Energy
Stored potential energy in the core, or nucleus, of an atom
Nuclear fission (split) produce electricity
Nuclear fusion (join) occurs in the sun and other stars

19. Answer Questions What are the two basic kinds of energy? Examples?
What are some of the different forms of energy? Examples?