Speed-time graphs show speed on the vertical axis and time on the horizontal axis. The gradient of a speed-time graph represents acceleration because:
= metres per second per second.
Metres per second per second can be written as or .
A negative gradient shows the rate of 'slowing down' or deceleration.
Velocity-time graphs show velocity on the vertical axis. Acceleration is still represented by the gradient.
The area under a speed-time graph represents the distance travelled. Likewise, the area under a velocity-time graph represents the displacement of the moving object. If the velocity is always positive, then the displacement will be the same as the distance.
Describe what is happening in this journey.
Between 0 and 4 seconds:
Between 4 and 7 seconds:
Between 7 and 10 seconds: