15 terms

Force

- a push or pull

Net force

- the combination of forces acting on an object

* opposite forces or direction- subtract

* same direction- add

* opposite forces or direction- subtract

* same direction- add

Balanced force

- opposite forces acting on an object that cancel each other out

* Net force is always 0

*object does not move

*does not change velocity

* Net force is always 0

*object does not move

*does not change velocity

Unbalanced force

- unequal forces that act on an object

* net force is never 0

* changes velocity of object

* net force is never 0

* changes velocity of object

Motion

- any change in position of an object

Speed

- the distance an object travels in a unit of time

* formula: distance /time = speed

* formula: distance /time = speed

Velocity

- speed in a particular direction

Acceleration

- any change in velocity

* speed up

* slow down

* change direction

* start

* stop

* speed up

* slow down

* change direction

* start

* stop

Friction

- the force that resists the motion of two touching objects

* resists motion

* resists motion

Newton's 1st law of motion

- An object at rest will remain at rest and an object in motion will continue moving in a straight line at a constant speed until an outside force acts against it.

Momentum

- a measure of how hard it is to stop an object's motion

* depends on mass and velocity

* more mass= more momentum

* more velocity = more momentum

* depends on mass and velocity

* more mass= more momentum

* more velocity = more momentum

Newton's 2nd law of motion

- An object's acceleration depends on the size and direction of the force acting on it and the mass of the object.

What affects acceleration?

1. size of the force

2. direction of the force

3. mass of the object

What affects acceleration?

1. size of the force

2. direction of the force

3. mass of the object

Newton's 3rd law of motion

- For every action there is an equal and opposite reaction

* forces always act in pairs

* equal and opposite pairs

* forces always act in pairs

* equal and opposite pairs

Inertia

- the tendency of an object to resist a change in its motion

Law of conservation of momentum

- momentum can not be transferred to another object

(unless an outside force acts on it, friction or gravity)

(unless an outside force acts on it, friction or gravity)