1. ENERGY & POWER

2. Energy = the ability to do work.
Work and Energy:are related, we give energy to an object by doing work on the object.
Measuring Energy: Because work is the transfer of energy, we can measure energy by measuring the work done.

3. For example if a boat does 5,000 Newton’s of work, the engine of the boat put out 5,000 N-m’s of energy.
One Newton meter is = to a Joule (J)
So to find out how much energy is needed to do something we use the formula for work.

4. Kinetic Energy: is the energy of motion.
If you stop a moving object you can feel it’s Kinetic Energy.
Kinetic Energy depends on two things.
Mass & Speed of the object.
More Kinetic Energy
100km/hr
100km/hr

5. Calculating Kinetic Energy:
KE=1/2mv2 answer is in Joules.
mass
velocity
Example: A girl has a mass of 40 kg skates around a rink at 12m/s. What is her Kinetic energy?

6. A boy has a mass of 120 kg runs at a speed of 4 m/s. What is his KE?
A man has a mass of 100 kg walks at a speed of 2 m/s. What is his KE?

7. 3. A baseball with a mass of 0. 08 kg is thrown at a speed of 20 m/s
3. A baseball with a mass of 0.08 kg is thrown at a speed of 20 m/s. What is the KE of the baseball?
4. A soccer ball with a mass of 2 kg is kicked at a speed of 5 m/s. What is the KE of the soccer ball?

8. Potential Energy: Is energy due to an objects position.
Calculating Potential Energy: Is work done or Force X Distance = Joules
Example: If a boy carries a 70 n bowling ball up a flight of 20 m high stairs. What is the balling ball PE?
Answer: 70 n X 20 m = 1400 J

9. Law of Conservation of Energy: States that energy cannot be created or destroyed. It can change from one form to another. But the total amount of energy remains the same. {EXCEPT SOME IS LOST DUE TO FRICTION}

10. Friction Wastes Energy:
The lower the friction the less energy wasted.
The less energy wasted the faster you go.
The less energy wasted the more PE converted to KE. PE
PE & KE
PE if
Stopped

11. Forms of Energy Mechanical: energy an object has from its motion.
Internal: energy from all the particles of an object.
Electrical: electricity

12. Chemical: energy from an objects position and its form of PE.
Radiant: energy in the form of a wave the sun
Nuclear: energy released from splitting or combining atoms.

13. Power: is the rate at which work is done.
Power = work/time it’s the rate at which energy is used.
Example: If a person used 1200 J’s of energy in 10 minutes how much power does that person have?
Answer: 1200 J / 10 minutes = 120 J/m
Some times we convert minutes to seconds for example 10 minutes = 600 seconds.10 X 60.
1 Joule per second is equal to a watt (W)
Power is measured in watts.

14. 1- Chemical Energy: Energy from an objects position. (Potential Energy)
2- Electrical Energy: Energy that flows through a wire (Kinetic Energy)
3- Energy: The ability to do work.
4- Internal Energy: Energy to the particles that make it up.
5- Joule: Metric Unit for energy.

15. 6- Kinetic Energy: Energy because the object is moving.
7- Law of Conservation of Energy: Energy cannot be created or destroyed. Energy changes from on form to another.
8- Mechanical Energy: Energy an object has from its motion.
9- Nuclear Energy: Form of Potential energy the splitting of atoms

16. 10- Potential Energy: Energy due to an objects position
10- Potential Energy: Energy due to an objects position. We give objects energy by doing work on them.
11- Power: The rate at which work is done.
12- Radiant Energy: Energy from the sun in the form of a wave.
13- Watt: Metric unit for power.

17. 14-If the rock's potential energy is100 J, the hill is _________ high.
15-At point C, the rock's potential
energy will be __________ . B
16-The rock's kinetic energy at point
A is __________. C
17-At point B, some of the rock's potential
energy will be changed to.
________________________________
18-The rock's potential energy at point
A is __________ than it's kinetic energy.