speed

tells us how fast something is going. distance divided by time

velocity

tells us how fast AND which way somthing is going.

acceleration

the rate at which velocity changes

m/s

unit of speed or velocity

meters, centimeters, inches, feet

unit of distance

force

a push or pull on a object

friction

the force that opposes the motion of an object

Air resistance

A type of fluid friction

Balanced force

When the net force = 0 newtons. An object is not moving or moving at a constant velocity at this time

unbalanced force

when the net force does not = 0.

sliding friction

a force that opposes the direction of motion of an object as it slides over a surface

rolling friction

friction that occurs when an object rolls over a surface

static friction

friction that acts on objects that are not moving

fluid friction

friction that occurs as an object moves through a fluid (includes water, air)

Inertia

The tendency of an object to resist change in its state of motion

Newton's First Law

Objects and rest tend to stay at rest. Objects in motion tend to stay in motion, unless acted on by an unbalanced force.

Newton's Second Law

The acceleration of an object depends on the mass of the object and the amount of force applied. F=m*a

Gravity

the downward pull on an object on Earth

Newton's Third Law

For every action there is an equal and opposite reaction.

Newtons (N)

Unit of force

Acceleration of gravity

9.8m/s2 on earth

meters per second squared (m/s2)

unit of acceleration

kilograms (kg)

unit of mass

Vector

a quantity that has magnitude and direction

normal force

the force that a surface exerts on an object that is pressing on it