Key learning points

1. Acceleration is equal to the gradient of a velocity-time graph.
2. A falling line shows decreasing velocity called deceleration, which is a negative acceleration.
3. Instantaneous speed at a point on a displacement-time graph equals the gradient of a tangent at that point.
4. The distance travelled is equal to the area under a velocity-time graph.
5. Displacement is equal to the net positive area under a velocity-time graph.

Keywords

• Displacement-time graph - A displacement–time graph shows the displacement of an object over a period of time.

• Velocity-time graph - A velocity–time graph shows the velocity of an object over a period of time.

• Velocity - The velocity of an object is the rate of change of displacement. This is how fast it is moving in a particular direction.

• Acceleration - The acceleration of an object is the rate of change of velocity. This is how much the velocity changes per second.

Common misconception