Question 14
A body, moving at 20 ms-1 accelerates uniformly at 2½ms-2 for 4 seconds. It continues the journey at this speed for 8 seconds, before coming to rest tseconds after with uniform retardation. If the ratio of the acceleration to retardation is 3 : 4,
Observation
The Chief Examiner reported that this question was poorly attempted by the majority of the candidates’ as they had difficulties in sketching the velocity – time graph. Majority of them started from the origin instead of 20 ms-1 thereby losing the marks allocated.
In part (a), they were expected to resolve vertically and horizontally as follows:
