Speed-time graphs
The speed-time graph below illustrates how the speed of an object changes with time.
A horizontal line on a speed-time graph represents a steady speed. This can also be called a constant or uniform speed.
A sloping line on a speed-time graph represents an accelerationThe rate of change in speed (or velocity) is measured in metres per second squared. Acceleration = change of velocity 梅 time taken.. The sloping line shows that the speed of the object is changing. The object is either speeding up or slowing down.
- The steeper the slope of the line the greater the acceleration.
- If the line slopes upward from left to right, this means the object is speeding up. Its acceleration will be positive.
- If the line slopes downward from left to right on the graph, this means that the object is slowing down. Its acceleration will be negative.