Physics+Chapter+2

=Motion, Forces, and Energy Chapter 2 Vocabulary Flashcards:= []

**A Force is a push or pull.**
==**A force may give energy to an object setting the object in motion, stopping it, or changing its direction.**==

**Unbalanced forces cause a change in motion**
NEWTON'S THREE LAWS OF MOTION

media type="youtube" key="UVdqxYyFRKY" height="315" width="420" Another Newton Law video:
 * ==The First Law (or the Law of Inertia ): An object at rest will remain at rest and an object in motion will remain in motion at constant velocity unless acted upon by an unbalanced force.==
 * ==The Second Law (or F=ma ): describes the relationship between force, mass, and acceleration. (A way to remember is F oxborough = Ma ssachusetts)==
 * ==The Third Law (or the A ction-Reaction law) states that forces always occur in pairs. For every action there is an equal and opposite reaction.==

**Friction is a force that opposes motion.**
==**The four kinds of friction are static, fluid, rolling, and sliding.**==

**Examples;**
An example of friction in action (Mythbusters - phone book)
 * ==**Sliding - ice skating**==
 * ==**Rolling - bowling**==
 * ==**Fluid - sky diving**==
 * ==**Static - any time you start an object in motion**==

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=**WHAT IS INERTIA?**=

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 * An example of inertia....**

**Gravity is a force of attraction that exists between all objects in the universe.**
==**Gravity depends on the masses of the two objects and the distance between the two objects.**==
 * ==**The larger the mass the greater the gravitional pull**==
 * ==**The further apart the objects are the less the gravitional pull**==

**Acceleration due to gravity on Earth is 9.8 m/s/s**
media type="youtube" key="Uy3nATe85Kg" height="315" width="420" =What is the difference between weight and mass?=
 * ==Weight is the measure of the pull of gravity on an object.==
 * ==Mass is the measure of the amount of matter in an object.==
 * ==Weight depends on gravity therefore it changes depending on where the object is in the universe.==
 * ==Mass is constant. It NEVER changes. It remains the same no matter where the object is in the universe.==
 * ==Weight is measured with a spring scale in Newtons.==
 * ==Mass is measured on a triple beam balance in grams (or kilograms).==

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