Motion: Inertia -- Physics Ch 3

Natural Motion

Motion that is either straight up or straight down; heavy objects fall and light objects rise.

Violent Motion

Motion imposed through an external force, such as being pushed or pulled.

Inertia

The property of a body to resist changes to its state of motion.

Friction

The force that acts between materials that touch as they move past each other.

Newton’s First Law of Motion

Every object continues in a state of rest, or of uniform speed in a straight line, unless acted on by a nonzero net force (unbalanced force).

Mass

The quantity of matter in an object; SI Base unit is Kg (Kilogram).

Weight

The force of gravity on an object; depends on an object's location.

W = mg

The formula relating weight (W) to mass (m) and gravity (g).

Constant Velocity

A state where an object moves at a steady speed in a straight line.

Gravity on the Moon

Approximately ⅙ of gravity on Earth, resulting in reduced weight but unchanged mass.

Example of Inertia

If a rock is thrown in space, it will keep moving in a straight line at a constant speed.

Copernicus

Proposed that the Sun is the center of the universe, challenging the geocentric view.