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

$\blue{\bold{\underline{\underline{Answer:-}}}}$

• 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

Answer:

Initial height =+10 m

Initial height =+10 mFinal Depth =−250 m

50 mTotal distance to be descended by the elevator =(−250)−(+10)=−260 m

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

60 mGiven, the time is taken by the elevator to descend −6 m=1 minuteThus, time taken by the elevator to descend −260 m= (−6)(−260)------- [from the formula :

speed= time,distance]

=60 minutes