Question

an elevator descends into a mine shaft at the rate of 9 per minute if the distance starts from 20 metre above the ground level how long will it take to reach - 250​

Answer 1

Answer:

Given,

speed=9m/s

total dis = distance above ground+distance below the ground

=

$20 + ( - ( - 250))$

$20 + 250 = 270$

as we know,

time=distance by speed

=270/9

=3 minutes