Contact and Non-contact Forces

What is a vector quantity?

A quantity that has both magnitude and direction (e.g. force, velocity, displacement).

What is a scalar quantity?

A quantity that has magnitude only and no direction (e.g. speed, distance, mass).

How are vectors represented?

With arrows; the length shows the magnitude and the direction shows the direction of the quantity.

What is the difference between velocity and speed?

Velocity is a vector (has direction), speed is a scalar (no direction).

What is a force?

A push or a pull acting on an object due to interaction with something.

What are the two main types of forces?

Contact forces and non-contact forces.

What is a contact force?

A force that acts when objects are physically touching (e.g. friction, tension, air resistance).

What is a non-contact force?

A force that acts when objects are not touching (e.g. gravity, magnetic force).

What happens when two objects interact?

They exert equal and opposite forces on each other (Newton's Third Law).

Example of non-contact force interaction?

The Sun and Earth attract each other due to gravity.

Example of contact force interaction?

A chair pushes on the ground, and the ground pushes back on the chair with equal force.