revision: Speed-time graphs

From speed-time graphs, you can calculate the acceleration and the distance traveled using the graph.

a) acceleration = gradient of speed-time graph,
(acceleration = change in speed/time taken)

b) distance traveled = area under graph

EXAMPLE:
a) The gradient of line OA = 20/10 = 2
Therefore, the acceleration in the first 10 seconds is 2m/s^2.

b) The distance traveled in the first 30 seconds is given by the area of OAD plus the area of ABCD.
Distance = (1/2 x 10 x 20) + (20 x 20)
              = 500m