Unit 7 Test Review

Force

A push or pull exerted on an object.

Motion

The action or process of moving or being moved.

Mass

The quantity of matter which a body contains.

Weight

The force exerted on a body by gravity.

Gravity

The force that attracts a body toward the center of the earth or another mass.

Speed

The rate at which an object covers distance.

Friction

The force opposing motion between two surfaces in contact.

Acceleration

The rate of change of velocity per time unit.

Inertia

The resistance to any change in an object's velocity.

Balanced Forces

Forces equal in size but opposite in direction, resulting in no change in motion.

Contact Forces

Forces that occur when two objects are in physical contact.

Non-contact Forces

Forces that occur without physical contact, such as gravitational and magnetic forces.

Newton's Third Law

For every action, there is an equal and opposite reaction.

Law of Universal Gravitation

States that every object attracts every other object.

Force (Units)

Measured in Newtons in the International System of Units.

Gravitational Force

Increases with mass and decreases with increased distance.

Unbalanced Forces

Forces that can change an object's speed or direction of motion.

Acceleration (definition)

The change in velocity per unit time.

Balanced Forces (effect)

Causes an object to remain at rest or move at constant speed.

Mass vs. Weight

Weight changes with location while mass remains constant.

Friction (cause)

Primarily caused by the roughness of surfaces.

Distance vs. Time Graph

Used to measure and represent the speed of an object.

Example of a Contact Force

Frictional force.

Effect of Doubling Distance

Gravitational force reduces to one-fourth.

Inertia

The tendency of an object to resist changes in its motion.

Speed (quantity)

Is a scalar quantity, not a vector.

Acceleration (changes in motion)

Can be caused by changes in speed or direction.

False Statements

It's false that weight is the same on Earth and the Moon.

Law vs. Theory

Theories explain phenomena, while laws describe observed behaviors.

True Statements

Gravity acts at a distance.

Newtons Second Law

Describes the relation between force, mass, and acceleration: F = m * a.

Friction Direction

Always acts in the direction opposite to the motion.