Question

Between two stations a train starting from rest first accelerates uniformly, then moves with constant velocity and finally retarts uniformly to come to rest. If the ratio of the time taken be `1 : 8 : 1` and the maximum speed attained be `60 km//h`, then what is the average speed over the whole journey ?
A. 25 km/hr
B. 54 km/hr
C. 40 km/hr
D. 50 km/hr

Answer 1

Correct Answer - A
`v_(av) = ("Total distance")/("Total time")`
Total distance = Area below `v - t` curve