1 A car travels on a straight horizontal race track. The car decelerates uniformly from a speed of \(20 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) to a speed of \(12 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) as it travels a distance of 640 metres. The car then accelerates uniformly, travelling a further 1820 metres in 70 seconds.

1. 1. Find the time that it takes the car to travel the first 640 metres.
   2. Find the deceleration of the car during the first 640 metres.
2. 1. Find the acceleration of the car as it travels the further 1820 metres.
   2. Find the speed of the car when it has completed the further 1820 metres.
3. Find the average speed of the car as it travels the 2460 metres.