Question

Suppose we represent the distance above the ground by a positive integer and that below the
ground by a negative integer. If it begins to descend from 15 m above the ground, what will be
its position after 45 minutes?

Answer 1

Step-by-step explanation:

Since downwards is negative, the velocity of the elevator is -5 m/min.

(i) Displacement = Velocity x Time = -5 m/ min x 60 min = -300 m.

(ii) Displacement from initial position = Velocity x Time = -5 m/min x 45 min = -225 m.

However, since we started 15 m above ground, displacement from the ground level = -225 + 15 m = -210 m.