Forces & Motion

Mechanics describes how objects move and what makes them speed up, slow down or change direction. (IGCSE uses $g = 10$ N kg⁻¹.)

Speed, velocity and acceleration

$$\text{speed} = \frac{\text{distance}}{\text{time}} \qquad a = \frac{v - u}{t}$$ Speed is a scalar; velocity is speed with direction.