Front

What is a balanced force?

Back

A balanced force is when two forces acting on an object are equal in size but opposite in direction, causing the object to stay still or move at a constant speed.

Front

What is an unbalanced force?

Back

An unbalanced force is when two forces acting on an object are not equal, causing the object to start moving, stop moving, or change direction.

Front

Give an example of balanced forces.

Back

A book resting on a table is an example of balanced forces. The weight of the book pulls it down, while the table pushes it up with equal force.

Front

Give an example of unbalanced forces.

Back

A soccer ball being kicked is an example of unbalanced forces. The force of the kick is stronger than the force of gravity, causing the ball to move.

Front

What happens when balanced forces act on an object?

Back

When balanced forces act on an object, it does not change its motion. It either stays still or continues to move at the same speed in the same direction.

Front

What happens when unbalanced forces act on an object?

Back

When unbalanced forces act on an object, it changes its motion. It can start moving, stop moving, or change direction.

Front

What is friction?

Back

Friction is a force that opposes motion between two surfaces that are in contact. It can be a balanced or unbalanced force.

Front

How does friction affect balanced and unbalanced forces?

Back

Friction can make unbalanced forces stronger or weaker. For example, it can slow down a sliding object, making the forces unbalanced.

Front

What is inertia?

Back

Inertia is the tendency of an object to resist changes in its motion. An object at rest stays at rest, and an object in motion stays in motion unless acted upon by an unbalanced force.

Front

How does inertia relate to balanced forces?

Back

Inertia helps explain why balanced forces keep an object at rest or moving at a constant speed. The object will not change its state of motion without an unbalanced force.