1. Potential and Kinetic Energy

2. Work = force x distance (W=Fd)
When work occurs 2 things happen:
The application of a force
The movement of something by that force
The unit of measurement is a combination
of force (N) with distance (m) to give a
newton-meter (N-m) or the Joule (J).
Rhymes with cool.

3. Both illustrations above show someone doing twice as much
2 loads lifted one story
1 load lifted two stories
Both illustrations above show someone doing twice as much
work. The first has twice the force required to lift 2 loads. The
second has twice the distance to lift one load. The illustration
below shows a weight lifter holding up a barbell, doing no work.
You do work on something when you force
it to move against the influence of an
opposing force – often friction.
No Work =
No Distance

4. How FAST the work is done is called Power.
Power = work done / time
Twice the power means an engine can do twice
the work in the same amount of time or the same amount of work in half the time.
The unit for is the joule per second, also known
as the watt.
In the U.S. we usually rate engines in units of horsepower & electricity in units of kilowatts. In
The metric system, autos are rated in kilowatts.

5. The three main
engines of the space
shuttle can develop
33,000 MW (mega-
watts) of power when
fuel is burned at the
enormous rate of
3,400 kg/s. This is like
emptying an average-
size swimming pool in
20 seconds!

6. The “something” that enables an object to do
work is Energy.
The two most common forms of fall under
the category of mechanical energy.
Mechanical Energy = the energy due to the position of something, or the movement of
something.

7. How is all energy divided?
Mechanical Energy
Potential
Energy
Kinetic
Energy
Gravitation
Potential
Energy
Elastic
Chemical

8. What is Potential Energy?
Energy that is stored and waiting to be used later

9. What is Gravitational Potential Energy?
Potential energy due to an object’s position
P.E. = mass x
height x gravity
Don’t look down, Rover!
Good boy!

10. What is Elastic Potential Energy?
Potential energy due compression or expansion of an elastic object.
Notice the ball compressing
and expanding

11. What is Chemical Potential Energy?
Potential energy stored within the chemical bonds of an object

12. What is Kinetic Energy? Energy an object has due to its motion
K.E. = .5(mass x speed2)