Question

7.
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?
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Answer 1

Answer:

If it starts from 5m above the ground then the total distance = - 205 -5 = -210 m

If it descends at 7m / hr

then

let the time be x

equating both sides

-210 / 7 = x

therefore x = -30 min

time cannot be negative.

therefore it will take 30 minutes to reach -205 m from 5m above the ground