Question

n elevator descends into mine shaft at the rate of 6 minutes per minute if it is end if it begins to descend from 20 metre above the ground what will be its position after 45 minutes

Answer 1

Answer:

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Grade 7

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Question 7

Q7) An elevator descends into a mine shaft at the rate of 6 m/min. If the descent starts from 10 m above the ground level, how long will it take to reach – 350 m.

Solution

Transcript

Solution 7:

Starting position of mine shaft is = 10m above ground

but,

it moves in opposite direction so it travels the distance (-350 m ) below the ground.

Total distance covered by mine shaft = 10m - (-350m)

= 10 + 350

= 360m

Now, taken to cover a distance of 6m by it = 1 minute

Time taken to cover a distance of 1m by it = \frac{1}{6\ }\min

6

1

min

Therefore, tie taken to a cover a distance of 360m = \frac{1}{6}\times\ 360\ =\ 60\ \min\ \

6

1

× 360 = 60 min

60 minutes = 1 hour

thus, in one hour the mine shraft reaches = 350 below the ground.