1. Energy and Work
January 2015
Arsenie

2. _____groups of Energy ___________Energy (PE) ___________Energy (KE)
It _____shown through ___________
Energy is stored and ready to do work
Elastic PE – a spring, a rubberband, a bow
Chemical PE – batteries, gasoline
Nuclear PE – the sun, bombs
_______PE – any object elevated
___________Energy (KE)
Object is in motion
ENERGY of MOTION

3. What is “_________” Energy?
Mechanical energy refers to objects in motion or that have the potential to move.
It is the…
Mechanical Energy is the property of an object that enables it to do ‘__________’.

4. Work is the _____of a ______
Work is the product of the _______(F) on an object and the ________(d) that object moved (in the same direction as the force).
Work is done to either:
change…
against….

5. SI Metric Units of Energy
Energy is measured in ________(J). This includes Work, Potential Energy, or Kinetic Energy.
1 Joule = 1 ______x 1 _______
1 Newton x 1 meter is also called a “____-____”.

6. think! Answer: Example problem You lift a 100-N boulder 2m.
Q. How much work is done on the boulder?
Answer:

7. _____________Energy:
Gravity exerts a force on this boulder. In order to move it, work must be done (against the existing force of gravity). Which example requires more work?
The boulder is lifted with 100 N of force.
The boulder is pushed up the 4-m incline with 50 N of force.
The boulder is lifted with 100 N of force up each 0.5-m stair.
Trick question! Answer:

8. Potential Energy But, it’s also ______and ______to Work!!!!!!
Because we would have to do work against gravity to lift something to get it elevated to store PE
Therefore, PE ______________to Work!
So, what is the gravitational potential energy of the boulder in the lifted position?
Answer:
Why?

9. and
So,
Then,
and
So,
Therefore,
W is equal and opposite to PE

10. Kinetic Energy
But it’s ALSO _______to the work required to bring something to its final motion or to rest because it is a conversion of potential energy.
…and potential energy is also equal to work and measured in Joules, and work is equal to force multiplied by distance. Therefore:

11. The Law of __________of ______
We have discovered a natural law of the universe that all energy is conserved.
Energy is not ____________or _____________.
All the energy that was here in the beginning is still here, and will be here until the end.
Energy simply converts from one form to another. For example, PE converts to KE.

12. Can you categorize each of these as Potential or Kinetic?
Forms of Energy
__________
Radiant (electromagnetic)
___________
Magnetic
___________
Sound
Luminous
Mass (E=mc2)
Dark (theoretical)
_____________
Can you categorize each of these as Potential or Kinetic?

13. Forms of Energy Thermal (KE) Chemical (PE) Electric (KE)
Radiant (KE) (electromagnetic)
Nuclear (PE)
Magnetic (KE)
Nutritional/food (PE)
Elastic (KE)
Sound (KE)
Mechanical (PE)
Luminous (KE)
Mass (E=mc2) (KE)
Gravitational (KE)
Dark (theoretical)