The graph below shows the speed, in m/s, of a car as it comes to rest from a speed of 10 m/s. Calculate the average speed of the car for this 10 second period.

Given: The graph below shows the speed, in m/s, of a car as it comes to rest from a speed of 10 m / s . Scale: x - a x i s 1 cm = 1 seconds y - a x i s 1 cm = 2 m / s average speed = area under the curve total time Area under the curve = area 1 + area 2 + area 3 = ( 1 2 × 3 × 6 ) + ( 4 × 3 ) + ( 1 2 × 7 × 4 ) = 9 + 12 + 14 = 35 m average speed = 35 10 = 3 . 5 m / s

The diagrams below is the speed-time graph for a car journey. Calculate the acceleration during the first 20 seconds of the journey.

Given: The diagram below is the speed-time graph for a car journey. acceleration = change in velocity time taken acceleration = 20 - 0 20 - 0 = 1 m / s 2 Thus, the acceleration in the first 20 seconds is 1 m / s 2

The diagram below is the speed-time graph for a car journey. Calculate the acceleration during the last 10 seconds of the journey.

Given: The diagram below is the speed-time graph for a car journey. acceleration = change in velocity time taken acceleration = 0 - 20 60 - 50 = - 2 m / s 2 Thus, the acceleration in the last 10 seconds is - 2 m / s 2 .

The diagram below is the speed-time graph for a car journey. Calculate the average speed for the whole journey.

Given: The diagram below is the speed-time graph for a car journey. Distance travelled=area under the velocity-time graph = area 1 + area 2 + area 3 = ( 1 2 × 20 × 20 ) + ( 30 × 20 ) + ( 1 2 × 10 × 20 ) = 200 + 600 + 100 = 900 m Average speed = total distance time taken Average speed = 900 60 = 15 m / s