Force and Motion   Jan 15, 2008   2:00/1:00 MT/PT
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The rate at which an object changes velocity or an increase or decrease in the rate of speed of a moving body. An increase in speed is called a positive acceleration; a decrease in speed is called a negative acceleration.
action and reaction

In every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object. The direction of the force on the first object is opposite to the direction of the force on the second object. Forces always come in pairs - equal and opposite.

air resistance Also known as drag - it pushes against things that are moving.
attracts  To cause to draw near by physical force (like a magnet.)
distance  The amount of space between two things, points, lines, etc.
electromagnetic force Is the force associated with electric and magnetic fields. It is responsible for structure, chemical reactions, and the attraction and repulsion that goes with electrical charge and magnetism.
external force Forces acting between the body and environment.


A push or a pull. A force can move objects. Force- A force is a push or a pull upon an object which results from its interaction with another object. You are doing work when you use a force to cause motion. A force is a push or pull. You can observe a force when something flies, falls, or spins.
friction Force from two objects rubbing against each other.
Galileo Often called the father of modern day physics. (Galileo)
gravity A force that pulls objects towards earth's center.
inertia The tendency of motionless bodies to remain motionless and moving bodies to remain in motion.
joule A unit of energy equal to the work done when a force of one Newton acts through a distance of one meter.
magnet An object that pulls metal or steel towards it.
mass A measure of quantity of matter in an object.
momentum A measure of the motion of a body equal to the product of its mass and velocity.
motion The action or process of moving or of changing place or position; movement.
Newton English philosopher and mathematician: formulator of the law of gravitation.

Newton’s 1st law of motion

An object in motion will stay in motion unless acted upon by an outside force or things will keep on doing what they are doing until something stops them. This is also known as inertia.

Newton’s 2nd law of motion Force = Mass x acceleration, which translates to this: the
more mass an object has, the more you have to push it. The harder you push an object, the farther it will go.
Newton’s 3rd law of motion When you push on an object, it pushes back, and is often referred to as action and reaction.
Physics The science of studying the concept of matter and its motion, as well as space and time. Physics is the science that deals with concepts such as force, energy, and mass.
push Something that moves things away from you.
resistance Is a force that tends to oppose or retard motion.
speed Rapidity in moving, going, traveling, proceeding, or performing.

unbalanced force

How far something goes in a certain amount of time.
velocity Measure of the speed and direction of an object.
weight Equals the amount of gravitational pull on an object.

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