Kinematics

Uniformly accelerated motion described by the kinematic equations relating displacement, velocity, acceleration, and time.

How to calculate average speed, distance, and time using the speed-distance-time triangle.

Distance is the total length of path travelled, regardless of direction — it is a scalar quantity. Displacement is the straight-line distance from start to finish, including direction — it is a vector quantity. Understanding the difference is essential in physics.

A distance–time graph shows how the distance of an object from a starting point changes over time. The gradient (slope) of the line gives the speed. A straight line means constant speed, a curved line means changing speed, and a horizontal line means the object is stationary.

Objects in free fall accelerate at g ≈ 9.8 m/s² downward. Projectile motion combines horizontal uniform motion with vertical free fall.

Uniform motion describes movement at constant velocity. Distance, speed, and time are related by d = vt.

Velocity is a vector quantity that describes both the speed and direction of motion. It differs from speed, which only has magnitude. Average velocity is calculated as displacement divided by time. Objects moving in opposite directions have opposite signs of velocity.