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

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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

ANSWER

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

Given, the time is taken by the elevator to descend −6 m=1 minute

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

------- [from the formula : speed= timedistance ]

=60 minutes OR 1 Hour