Definition: Net force is the vector sum of all individual forces acting on an object.

Example: For a 2000 N object with a coefficient of sliding friction of 0.20, the friction force would be 400 N.

Highlight: When two forces act in opposite directions, the net force is the difference between them.

Vocabulary: Coefficient of friction - A measure of the roughness between two interacting surfaces.

Quote: "The force of friction always opposes whatever motion is causing the friction."

Definition: Force is a push or pull acting on an object that can change its motion or shape.

Vocabulary: Newton (N) - The SI unit of force, equal to 1 kg⋅m/s²

Example: When a person pushes a scooter, they apply a force that controls its speed and direction.

Highlight: Newton's 1st Law states that an object at rest stays at rest, and an object in motion stays in motion unless acted upon by an unbalanced force.

Quote: "Every time the motion of an object changes, it's because a force has been applied to it."