1. HON PHYSICS DAY 35
Energy again!

2. REMIND ME
Why did the roller coaster have fallback sometimes but other times did not?
How did the coaster able to make it to the top usually?

3. Work/Energy Review…a set of ideas
Remind Me:
Kinetic Energy
Idea: Equation:
Grav. Potential Energy

4. The change of an energy type is called:
In an isolated system, how should the total amount of energy compare before and after some time?

5. Kinetic Energy
(1/2)m(v2)
Gravitational Potential
m(g)h
System Energy
At starting height
Striking the floor

7. Lets Try Some
In this coaster

8. Kinetic Energy
(1/2)m(v2)
Gravitational Potential
m(g)h
System Energy
At A
At B
At C

9. THE SAME! No loss of system energy!
Lets Try Some
If this is an isolated system, how does the system energy at A compare to C?
THE SAME! No loss of system energy!

10. A has MORE GPE because it is higher!
Lets Try Some
If this is an isolated system, how does the Potential energy due to gravity at A compare to C?
A has MORE GPE because it is higher!

11. Lets Try Some
Now lets come up with a sentence to describe what is happening to the system energy between:
A and B also B and C

12. Would a heavier cart have more/less/same speed at C?
Lets Try Some
Would a heavier cart have more/less/same speed at C?

13. ACTIVITY

14. WORK!
Work is not just a change in energy, but also a FORCE times a DISTANCE.
We use tables to get it, usually.