1. W: What do you want to know? L: What did you learn?
KWLQ
What is Energy?
K: What do you know?
W: What do you want to know?
L: What did you learn?
Q: What questions do you have?

2. Notes: Energy

3. Energy is the ability to work.
NOTES
Energy is the ability to work.
Work is done when a force exerted on an object moves that object some distance.
Work is a transfer of energy

4. Units are: Newtons x meters
Both work and energy are measured in joules.
Work & energy is force times distance
Units are: Newtons x meters or
Joules

5. Two Types of Energy Kinetic Energy Energy associated with motion
Ex. Dropping the bowling ball.
Potential Energy
Stored energy
Ex. Lifting a bowling ball to a height.

6. Kinetic Energy= 1/2mass X velocity squared
Kinetic Energy = ½m x v²

7. = J
KE = (½ 3600Kg) X (10m/s)²
Kinetic energy depends on the square velocity! So at twice the speed the truck has 4 x the energy
If the truck has a mass of 3,600Kg and a velocity of 10m/s, what’s it’s Kinetic energy?
A more massive truck has more kinetic energy.

8. Equation for Gravitational Potential energy
PEgrav = mass x gravity x height or
PEgrav = m x g x h

11. Another type of Potential Energy
Elastic PE
PE associated with objects that can be stretched or compressed.

12. Elastic Potential Energy

13. Gravitational Potential Energy
50Kg
10 meters high
PEgrav = mass x gravity x height
= 4900J
PEgrav = 50Kg x 9.8m/s/s x 10m

14. Now calculate Kinetic Energy
50Kg
Now calculate Kinetic Energy
What’s its velocity if it falls for one second?
Kinetic Energy = ½m x v²
= 2401 J
KE = (½ 50Kg) X (9.8m/s)²

15. Energy conversion – a change from one form of energy to another form.

16. Energy conversion cont…
Most forms of energy can be converted into other forms
Example: Mechanical energy (running water) can be converted into electrical energy (electricity)

17. For example burning coal at an electrical power plant converts chemical energy into heat. The heat makes steam which turns turbines mechanical energy to make electrical energy. The electrical energy is converted back into heat (oven), light (lights in the house), and mechanical energy (a car’s engine) when it is used.
Gas  engine
photosynthesis
Food  your body
Heat lamp or hair dryer
Oil  electricity via power plant

19. Conservation of Energy
Law of Conservation of Energy: when one form of energy is converted into another form of energy, no energy is destroyed in the process
Energy can not be created or destroyed

21. Different Forms of Energy
Mechanical = motion or position of an object
Thermal = total energy of the particles in an object (the more energy the more heat is given off)
Chemical = PE stored in chemical bonds (food)

22. Electrical = energy caused by moving electric charges

23. Electromagnetic energy = visible light, microwaves, x-rays, and uv light

24. Nuclear = fission and fusion

25. Power Power is the amount of work done in a given time.
Equation for power
Power = work/time or
Power= force x distance/time

26. Power cont…..
Units for Power
Joules/second or…
Watt (w)

29. Formation of fossil fuels
In the earth’s crust, under distinct pressure, temperature and geological processes, nonrenewable energy formed from once living organisms.

31. Common Types of Fossil Fuels
Coal
Oil (petroleum)
Natural Gas

32. Fossil Fuels make good fuels because the energy stored in them is abundant and easy to release when heated.
Methane            CH4             (gas)
Ethane              C2H6           (gas)
Propane            C3H8           (gas)
Butane              C4H10         (gas)
Pentane             C5H12         (liquid, found in gasoline)
Hexane             C6H14         (liquid, found in gasoline)
Heptane            C7H16         (liquid, found in gasoline)
Octane              C8H18         (liquid, found in gasoline)
Pentadecane       C15H32       (liquid, found in kerosene  and jet fuel)
Tetracosane       C24H50        (liquid, found in lubricating oil)

33. Some common uses of Crude Oil
Solvents
Fertilizers
Pesticides
Plastics
Diesel fuel
Jet fuel
liquified petroleum gas
plastics
Kerosene
Synthetic fibers
Synthetic rubber
Detergents

37. Source: Energy Information Administration