Acceleration
The rate of change of velocity with time, calculated as a = Δv/Δt (where v is velocity and t is time). A vector quantity (has direction), measured in m/s². Zero acceleration means constant velocity (including zero velocity, i.e., stationary). Newton's second law: F = ma relates force and acceleration.
Formula
a = Δv / Δt
Real World
A skydiver in free fall near Earth's surface accelerates at 9.81 m/s² downward until air resistance balances gravity, after which acceleration becomes zero and terminal velocity is reached.
Exam Focus
On a velocity–time graph, calculate acceleration from the gradient; don't confuse the area under the graph (displacement) with the gradient (acceleration).
How well did you know this?