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a push or a pull

Net Force

the force after the counteracting force

Unbalanced force

whenever there is a net force acting on an object

Balanced Force

equal forces acting on one object in opposite directions


object is in motion if its distance from another object is changing


the tendency of an object to resist a change in motion or stay still


a measure of the amount of matter in an object

Newton (the unit)

The unit that measures the strength of a force (1 km in mass at 1 mile per second)


the force that two surfaces exert on each other when they rub against each other

Sliding Friction

when two solid surfaces slide over each other

rolling friction

when an object rolls over a surface

fluid friction

when a solid object moves through a fluid


a force that pulls object towards each other


the force an object exerts on something toward the earth


is a characteristic of a moving object that is related to the Mass and the Velocity of the objects

terminal velocity

final speed

Law of conservation of momentum

in the absence of outside forces, the total momentum of the object that hit each other does not change

centripetal force

any force that causes an object to go in a circle

theory of plate tectonics

earth's land masses have changed position over time because they are part of plates that are moving slowly

Frame of reference point

A place or object used for comparison to determine if an object is in motion

Acceleration and deacceleration

increasing speed or decreasing speed or changing direction


any object that orbits another object in space


speed and direction




the speed and direction of an object's motion


SF-SI/time or force/mass



Control Group

what you compare

Experimental Group

what you base the experiment on

Independent variable

what you change in an experiment

Dependent Variable

What you measure (measurements)

Newton's 1st Law of Motion

Objects at rest will remain at rest unless acted upon by an outside force.Objects in motion will remain in motion at the same velocity unless acted upon by an outside force.

Newton's 2nd Law of Motion


Newton's 3rd Law of Motion

To every action there is an opposite and equal reaction.

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