Forces and Motion

A force is a push or a pull. Forces make things move, stop, speed up, slow down, or change direction.

Types of Forces

Gravity

Gravity is a pulling force. It pulls everything towards the centre of the Earth. Gravity gives objects weight. On the Moon, gravity is weaker.

Friction

Friction is a force that slows things down when two surfaces rub together. Rough surfaces = more friction. Smooth surfaces = less friction.

Air Resistance

Air resistance is friction between an object and the air. Streamlined shapes reduce air resistance. Parachutes increase air resistance to slow you down.

Balanced and Unbalanced Forces

• Balanced forces = object stays still or moves at the same speed
• Unbalanced forces = object speeds up, slows down, or changes direction

Newton's Three Laws

1. An object stays still or moves at the same speed unless a force acts on it
2. The bigger the force, the bigger the acceleration
3. Every action has an equal and opposite reaction

Measuring Forces

We measure force in Newtons (N), named after Sir Isaac Newton.

Activity: Toy Car Investigation

Push a toy car across different surfaces (wood, carpet, grass) and measure how far it goes.