1. Energy
Seo
Physics

2. Objectives To find how energy conserves and converts to other forms
To apply understanding of storing and moving energy

3. Energy is always conserved Units? Joules (J) 2 main categories :
What is Energy? (E)
aka. Storage Mechanism
change in Work (ΔW)
Energy is always conserved
Units?
Joules (J)
2 main categories :
Kinetic and Potential

4. Kinetic Energy 5 different forms What is Kinetic Energy? (Ek or EKE)
Energy of motion
Equation?
KE = ½ x m x v2
m=mass; v=velocity
Units?
Joules (J)
5 different forms
mechanical, electrical, thermal, electromagnetic, and light

5. Practice
What is the Kinetic Energy of a 150 kg object that is moving with a speed of 15 m/s?

6. DIY
What is the Kinetic Energy of a 478 kg object that is moving with a speed of 15 m/s?

7. Potential Energy Units? 5 Forms of Potential Energy
What is Potential Energy? (EP or EGP)
Stored energy
Energy of position
Equation?
GPE = m x g x h
m= mass; g=gravity; h=height
Units?
Joules (J)
5 Forms of Potential Energy
Chemical, Elastic, Electric, Magnetic and Nuclear

8. Practice g=9.8 m/s2 GPE= mgh GPE= 10 kg x 9.8 m/s2 x 4 m 392 J
What is the Gravitational Potential Energy of a kg object at 4.00 m above the ground?
g=9.8 m/s2
GPE= mgh
GPE= 10 kg x 9.8 m/s2 x 4 m
392 J

9. Elastic Potential Energy
What is EPE? (EEL or EEP)
Energy stored in a stretched or compressed spring.
Equation?
k= Spring constant (units: N/m)
x= distance of stretch /compression in spring
Units?
Joules (J)

10. Practice
A 1 kg crate is suspended on a spring. How much elastic potential energy is stored in the spring if the pear stretches the spring m? k= 9.6 N/m

11. Chemical Potential Energy?
What is CPE? (ECh)
Energy stored during bonding between molecules
Released from chemical reactions
Ex. Burning, Fuels, Battery, and Heaters

12. Mechanical Energy What is a Mechanical Energy? (ME) Equation?
The total of Kinetic and Potential Energy
Equation?
ME = KE + PE
Describes how energy is stored and used

13. Energy Pie Charts 1. Determine Energy forms for the scenario
2. Draw a pie graph for number of pictures shown per frame
3. Show energy storages changing for different frames
EX.

14. Pie Chart Practice
A moving cart slows slightly as it rolls toward a spring, and then comes to a stop by compressing the spring.
Sketch energy pie charts representing energy storage for each stage

15. Conservation of Energy
What is Conservation of Energy?
Energy is conserved from one form to another
Will not losing original energy
Energy cannot be created or destroyed
Total amount of energy never changes
Equation Format
Ei1+ Ei2 = Ef1+ Ef2

16. The total initial energy must equal the total final energy.
LOL Bar Charts
Helps us analyze the energy transfer
The total initial energy must equal the total final energy.

17. LOL Bar Chart Practice
Suppose a cart is speeding on the highway, initially. Towards the end, it bounces off to a spring bumper and slows down