MFE - Friction and Gravity

Friction

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

Static friction

The friction acting on objects not moving

Sliding friction

Occurs when to solid forces slide over each other

Rolling friction

Occurs when an object rolls across a surface

Fluid friction

Occurs when a solid object moves through a fluid

Factors Affecting Gravity

The factors that affect gravity are mass and wieght

Free Fall

Occurs when the only force on an object is gravity

Air Resistance

When an object is falling through the air, it experiences this kind of fluid friction.

Projectile

An object that is thrown. (Not dropped)

Universal Gravitation

Newton realized that gravity acts everywhere in the universe! (Not just on Earth)

Gravity

A force that pulls objects toward each other. (NOT down)

Mass

The amount of matter in an object

Weight

The measure of the force of gravity on an object. (Remember - No gravity, no weight!)

Terminal Velocity

The greatest velocity an object can reach while in a free fall.