# An elevator descends into a mine shaft at the rate of 6 m/min. If the descent starts from 10 m above the ground level, how long will it take to reach - 350 m.

Solution

From the given details we get to know that

The initial height of the elevator = 10 m

The final depth of elevator = – 350 m … [∵distance descended is denoted by a negative integer]

Total distance to be descended by the elevator = (−350) − (+10) = −360 m

Time taken by the elevator to descend −6 m = 1 min

Thus, time taken by the elevator to descend −360 m = (−360) ÷ (−6)

= 60 minutes = 1 hour

Time taken by the elevator to descend = 1 hour