Question

an elevator descends in to a mine shaft at the rate of 7m/min. if he descent starts from 5m above the ground level, how long will it take to reach -205m?​

Answer 1

the total height for the mineshaft to cover is 475+15= 490 m

for covering the distance the mineshaft requires=(490/7 )min

=70 min

= 1hr 10 min

Answer 2

Step-by-step explanation:

Distance descended is denoted by a negative integer.

Initial height = +10 m

Final depth = −350 m

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