Chapter 3: Motion, Acceleration, and Forces

Vector

: A quantity that is specified by both a size and a direction.

Acceleration

: the change in velocity divided by the time for the change to occur.

Force

: a push or pull that one object exerts on another.

Terminal Velocity

The is the highest velocity the falling object will reach.

Air Resistance

: opposes the motion of objects that move through the air.

Friction

: the force that opposes the sliding motion of two surfaces that are in contact.

Displacement

: the distance and direction of an objects final position from its initial position.

Reference Frame

a group of objects that are not moving relative to each other

Displacement

the distance and direction of an objects final position from its initial position

Speed

the distance an object travels per unit of time

Instantaneous Speed

the speed at a single instant of time

Average Speed

the total distance traveled divided by the total travel time

Velocity

the speed of the object and its direction of motion

Acceleration

the change in velocity divided by the time for the change to occur

Net Force

When two or more forces act on an object at the same time

Balanced Forces

Forces on an object that are equal in size and opposite in direction

Unbalanced Forces

When forces combine to produce a net force that is not zero, the forces acting on the object

Static Friction

the frictional force that prevents two surfaces in contact from sliding past each other

Sliding Friction

the frictional force that prevents two surfaces in contact from sliding past each other

Rolling Friction

When an object rolls over a surface, a frictional force due to rolling friction slows the object down