1. Energy, Motion, and Forces
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Energy, Motion, and Forces

2. Kinetic and Potential Energy
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Kinetic and Potential Energy

3. What is energy? Energy – the ability to cause change
Work is accomplished when a force causes an object to move in the direction of the force
Work = force x distance
Measured in joules (J)
Named after James Prescott Joule
English Scientist who work to improve electric motors. Study heat and it relationship to work. Paved the way for the theory of the conservation of energy

4. What are two types of energy?
Takes many different forms and has many different effects
Ex: Your body uses energy provided by the food you eat and converts it to other forms
The two types of energy are called kinetic energy and potential energy

5. What is Kinetic Energy? Kinetic Energy is the energy of motion
The amount of KE that an object has depends on two things: mass and speed(KE = ½ m*s*s)
Speed has a greater impact = (KE=mv2/2)
Ex: a car and a bike are both moving at the same speed  the car has more mass so it has more KE
Ex: A cheetah has more KE when it is running than it does when it is walking or sitting under a tree

6. What is Potential Energy?
Potential Energy is the stored energy that an object has due to its position
One type of PE is called gravitational PE  depends on the mass and height of object (GPE = m*9.8*h OR GPE = w * h)
Ex: A skydiver has more GPE on the plane than she does after she jumps out and gets closer to the ground
Ex: A heavy book has more GPE than a lighter book when they are sitting on the same shelf

7. How are kinetic energy and potential energy different?
KE is the energy of motion, but PE is stored energy that can be converted into motion
Many objects can have both KE and PE
Ex: an object can be both moving and above ground
If you are walking (KE), you still may trip and fall (PE)

8. What is mechanical energy?
Mechanical energy is the KE plus the PE due to position (ME = KE+PE)
Ex: A skate boarder on a half-pipe has both KE and PE. At the very bottom of the half-pipe, his KE is greatest and his PE is lowest. At the top of the half-pipe, his PE is greatest and his KE is lowest.
Ex: Roller Coaster sheet

9. What is the Law of Conservation of Energy?
The Law of Conservation of Energy states that energy can neither be created nor destroyed  It can only be transformed!
Ex: When I pick up a book, I am using my KE to increase the book’s GPE

10. Forms of Energy Gravitational Electricity Nuclear Motion Mechanical
Chemical
Electricity
Motion
Radiant (light)
Sound
Thermal