A lift starts from rest at the ground floor and moves vertically upward
PHYSICS · Subjective · CBSE · Physics · Motion in a Straight Line · Motion in a Straight Line
Problem
A lift starts from rest at the ground floor and moves vertically upward. It accelerates uniformly at 2 m s⁻² for 3 s, then continues at constant speed for 4 s, and finally decelerates uniformly at 3 m s⁻² to come to rest at the 8th floor. Taking downward as the positive direction,
(i) state the sign (positive, negative or zero) of the acceleration in each of the three phases,
(ii) calculate the net displacement of the lift and hence find the vertical distance between the ground floor and the 8th floor.