AS Kinematics Part 1

What these notes cover

These notes cover the first half of Kinematics for Cambridge International AS Level Physics (9702): distance and displacement, speed and velocity, acceleration, and how to read displacement–time and velocity–time graphs. They also derive and apply the equations of uniformly accelerated motion, including free fall near the Earth’s surface. Projectile motion is covered in Kinematics Part 2.

Key formulas and definitions

• Displacement is distance in a specified direction (a vector); distance is a scalar.
• Acceleration is the rate of change of velocity: a = Δv / Δt
• Gradient of a displacement–time graph = velocity; gradient of a velocity–time graph = acceleration.
• Area under a velocity–time graph = displacement.
• v = u + at
• s = ut + ½at²
• v² = u² + 2as
• s = ½(u + v)t (the four equations apply to constant acceleration only)
• Acceleration of free fall near the Earth’s surface: g = 9.81 m s⁻²