Question

The elevator descends at the rate of 5m/ Mon. If the descent stars from 50 m above the ground level, find the time taken by the elevator to reach - 250 m?????​

Answer 1

$\huge\mathbb\red{Answer:-}$

Initial height = 50m

Final depth = -250m

Here we took the final depth as negative because the elevator is descending ( going down)

Total height descent by the elevator

= 50- (-250)

= 300m

As the elevator descends at 5m/min

Time taken by the elevator to descend 5m = 1 minute

Time taken by the elevator to descend 1m = 1/5 min

Therefore:-

Time taken by elevator to descend -300m

= $\sf \dfrac{ 300}{ 5}$

60min = 1hour.

Therefore:-

Time taken by elevator to reach - 250m is 1 hour.

Answer 2

Distance descended is denoted by a negative integer,

Initial height = +50 m

Final depth = -250 m

Total distance to be descended by the elevator =(-250) - (+50) = -300 m

Given, the elevator descends at the rate of 5m/min.

Time taken by the elevator to descend 5m = 1 minute

So, time taken by elevator to descend 300m is

= 1/5 x 300

= 300/5

= 60 minutes

= 1 hour

Hence, Time taken by elevator to reach -250m is 1 hour.