Forces and Motion

Acceleration

A change in velocity with respect to time. Acceleration. Acceleration is how quickly an object's speed or direction changes.

Balanced force

Forces that are equal but in opposite directions. Balanced force. In science, a balanced force means that an object stays still or continues to move at the same speed in the same direction because the forces acting on it cancel each other out.

Force

The push or pull exerted on an object. Force is what causes objects to move or change direction.

Friction

The force that opposes motion between two surfaces that are touching. Friction is what slows down objects when they slide or roll over each other.

Gravity

The attractive force between all objects that have mass. Gravity is the invisible pull that makes things fall to the ground and keeps planets in orbit.

Inertia

The tendency of objects to resist any change in motion. Inertia. Inertia is the reason why an object at rest stays at rest, and an object in motion stays in motion unless acted upon by an external force.

Speed

The distance an object travels per unit of time. Speed. Speed is how fast something is moving from one place to another.

Unbalanced force

Forces acting on an object to cause a change in motion. Unbalanced force. An unbalanced force occurs when different forces on an object are not equal, causing the object to move.

Velocity

Speed and direction of a moving object. Velocity. Velocity is how fast something is moving and in which direction.

Work

The use of force to move an object over a distance, its unit is the Joule J. Work is when a force makes something move.