An elevator is required to carry passengers from the ground floor to a floor 20m above. Starting from rest, it accelerates upward uniformly at 1.5m/s2 for 2.0s, then moves with the constant speed thus attained, and finally decelerates uniformly at 1.0m/s2 for 3.0s to come to rest exactly at the destination floor.
Solve the following.
(i) Determine the speed of the elevator at the end of the initial 2.0s.
(ii) Calculate the distance covered during the initial acceleration and during the final deceleration.
(iii) Using the total vertical distance of 20m, find the time for which the elevator travels at constant speed.
(iv) Obtain the total time of the ride and sketch the complete velocity–time graph, clearly marking all key values.