Remember, acceleration is the same as gradient, and acceleration = velocity change ÷ time. Look at the graph. The acceleration of the vehicle in the first 10 seconds is: ...

The acceleration here would depend on the units for the velocity. If I go with 20 m/s then the acceleration would be 1 x 10 7 m/s 2 . 20 mph would give an acceleration of 4.5 x 10 6 m/s 2 .