I. Motion - An object is in motion when the distance between it and another object or point is changing.

A. Motion can only be judged by using a reference point or frame of reference.

1. Think about closing your eyes while riding in a car on a smooth highway -

it doesn’t feel like you are moving, but if you look out the window you can

tell.

2. We are in constant motion as the earth spins and revolves around the sun

- we move at around 800 miles per hour as Earth spins and 66,000 miles

per hour as Earth revolves around the Sun. But we don’t feel either of

these motions. Why?

B. A reference point is a location or object that you can use to determine if an object is moving.

1. If the distance between an object and a reference point is changing then

the object is in motion. Most reference points are stationary - NOT

moving.

C. Motion can be described in terms of its speed and its direction.

II. Speed - The amount of distance an object travels in 1 unit of time.

A. If you have measured the distance an object has travelled and how long it took it

to travel that distance you can calculate speed.

1. Formula for speed is speed = distance / time

2. Speed can NOT be measured - it has to be calculated.

3. The unit for speed is always a distance per time - miles per hour,

centimeters per minute, meters per second, etc..

B. Constant speed is when an object travels at the same speed over an extended

period of time.

C. Variable speed is when an object speeds up or slows down - changes speed.

D. Average speed is when you take the total distance travelled and divide it by the

total time - it ignores the changes in speed during a trip and just gets an average

for entire trip.

III. Velocity - An object’s speed and direction.

A. Velocity changes when the speed or direction or both change. Often describes

with compass directions example - going South at 60 miles per hour.

I. What is Energy?

A. Energy is defined as the ability to do work or cause a change.

1. Work is defined as moving a mass a certain distance - more mass

or more distance equals more work!

B. We use energy during every moment - energy is what allows us to move and our

heart to beat. Energy propels cars and runs our computers.

C. Two main categories of energy - Kinetic and Potential

D. Kinetic Energy

1. Kinetic energy is the energy of a moving object - the amount of kinetic

energy an object has depends on the speed of the object and the mass of

the object.

E. Potential Energy

1. Potential energy is energy an object has due to its position or its

condition.

2. Some object have energy because they are stretched out or

compressed like rubber bands or springs. Some objects have energy because of where

they are - a car at the top of a steep hill.

II. Forms of Energy - 8 forms of energy that we will learn - some are just potential or kinetic

but many are a combination of both categories.

A. Gravitational Potential Energy

1. Potential energy an object has because of the force of gravity acting

upon it.

2. A bowling ball on the roof of a building has a lot of potential energy

because gravity is pulling it down - if I drop it onto a teeter-totter I could

make something fly up.

3. The amount of energy depends on the strength of gravity and the height

of the object from the source of gravity.

B. Elastic Potential Energy

1. Potential energy an object has because it is either stretched or

compressed.

2. Common examples are rubber bands and springs.

C. Mechanical Energy

1. The energy in a moving object - a combination of potential and kinetic

energy.

2. As a person swings on a swing set their energy is constantly changing

back and forth between potential and kinetic. Except for when they are at the top or

bottom they have both types of energy.

D. Thermal Energy

1. The kinetic energy that the moving particles have in a substance.

2. The higher the temperature the faster the particles move and the higher

the thermal energy.

3. Temperature is how we measure the thermal energy.

4. Adding or subtracting thermal energy can cause a substance to

change state or phase.

E. Chemical Energy

1. The potential energy an object has due to the bonds that hold its

particles together.

2. This is the energy in food and gasoline.

F. Electrical Energy

1. The kinetic energy of moving electrons that create electricity.

2. Electrical energy moves through wires to power our computers.

3. Naturally occurs in lightening.

G. Electromagnetic Energy

1. The energy in light waves, infrared and ultraviolet radiation.

2. Sunlight is electromagnetic energy and is the primary source of all

energy on Earth.

H. Nuclear Energy

1. The potential energy due to the bonds holding the parts of an atom

together.

2. This is the energy used in a nuclear reactor or nuclear bomb.

a. In a reactor the release of the energy is controlled while in a

nuclear bomb the release is uncontrolled and almost instant.

I. Sound Energy

1. The kinetic energy that a sound wave produces in the stuff through

which it travels.

2. No sound in space because there is nothing for the sound to travel

through.

3. Sounds are different underwater because the sound waves travel

differently in water than through air.