Unit+Five

=Unit Five: What Is Energy?= (Lars) The forms of energy- Electrical energy is the energy of movig electrons Thermal energy is the total energy of the particles that moake up an object Chemical energy is the energy of a compound that changes as it's atoms are rearranged to form new compounds Light energy is produced by the vibrations of electrically charged particles Nuclear energy is th4e energy associated with changes in the nucleus of an atom Sound energy is caused by an objects vibration(Lars)
 * Electrical**-
 * Thermal**-
 * Chemical**-
 * Light**-
 * Nuclear**-
 * Sound**-


 * Potential Energy**

Examples- a stretched rubber band, a bow and arrow
 * Stored energy
 * Depends on weight and height
 * Keeps the same shape-Keeps the energy
 * Work has to be done to change the shape
 * Kinetic Energy**


 * The more mass and speed object has, the more kinetic energy is in use
 * The harder you work, the more energy you will use
 * Energy is the ability to do work
 * Work is a transfer of energy
 * Everything has energy
 * What is the relation between work and energy?**
 * Energy is the ability to do work

=Chapter 5, Section 3: Friction=

(Lars)**Friction**: A force that opposes motion between two surfaces that are touching

Friction is caused when microscopic hills and valleys slide into place with eachother and friction is created. No matter how smooth an object is, it will always have hills and valleys. Rougher surfaces have more hills and valleys than a smouth surface The amount of surface that an object touches does not change the amount of friction
 * What Causes Friction?**


 * Types of Fricton**
 * **Sliding**- Needs a lot of force-examples- applying car or bike brakes,
 * **Rolling**- Much easier than sliding- the friction is decreased jurastically- examples- cars, bikes, planes, practically anything that rolls
 * **Fluid**- Traveling through fluid
 * **Static**- Were a small force is applied but not enough to move the force(Lars)

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 * __Friction Friend or Foe?__**
 * Friction is both it is what makes cars go and what makes your socks get holes and what wears down on topsoil. without friction we would not be able to stand or walk. Here is a video on friction.

=Chapter 5, Section 4: Gravity=

(Lars)Gravity: a force of attraction between abjects Gravity affects all matter because all matter has mass (Lars)

Experiment 1/16/08
(Lars)Mass does not affect the rate of fall Air resistance creates friction and slows object down The greater the surface area the greater the friction Falls straight- ex. Hammer Gravity is always pulling objects toward you(lars) Gravitational force increases between objects depending on the mass of the objects. Gravitational force decreaces as distance increases hence why you dont float to the moon or the sun. Wieght is a measure of the gravitational force put on an object which is why it is unreliable and is not used by scientists Wieght can also be expressed in Newtons on earth 100 grams a medium sized apple wieghs roughly 1 Newton. Wieght and mass are different mass is measured using balance wieght is balanced by a spring scale.(Gino).