Question

An elevator descends into a shaft at the rate of 3 m/min. If the descent starts from 40 m above the ground level, how long will it take to reach -20 m?

Answer 1

Answer:

Very easy.

Speed= 3m/min

Time taken to travel 20m to the ground level (t1)

=Distance/Speed

=20/3 mins

Time taken to travel -240m (240m below ground level) (t2)

=Distance/Speed

= 240/3 mins

= 80mins

Total time taken= t1+t2= 86.66 mins.

I hope this helps.

Answer 2

Answer:

Total distance to be covered by the elevator

= 40m above the ground + 20 m below the ground

= 60 m

Rate of descent = 3m/min.

$time \: taken \: = \frac{total \: distance}{rate \: of \: descent} = \frac{60}{3 \: m/min} = 20 \: min$

✅ Hence the required time = 20 minutes