3
\includegraphics[max width=\textwidth, alt={}, center]{f1f33ef0-0d4d-4a4a-aadb-28de8dc0ea8d-04_666_1278_280_424}
The diagram shows the velocity-time graph for the motion of a bus. The bus starts from rest and accelerates uniformly for 8 seconds until it reaches a speed of \(12.6 \mathrm {~ms} ^ { - 1 }\). The bus maintains this speed for 40 seconds. It then decelerates uniformly in two stages. Between 48 and 62 seconds the bus decelerates at \(a \mathrm {~m} \mathrm {~s} ^ { - 2 }\) and between 62 and 70 seconds it decelerates at \(2 a \mathrm {~m} \mathrm {~s} ^ { - 2 }\) until coming to rest.
- Find the distance covered by the bus in the first 8 seconds.
- Find the value of \(a\).
- Find the average speed of the bus for the whole journey.