Question

Suppose we represent the distance covered by a positive integer and that below the ground by a negative integer,then answer the following :-
i) An elevator descends into a mine shaft at the rate of 5 metre per minute . What will be its position after one hour?
ii) If it begins to descend from 15m above the ground,what will be its position after 45 minutes ?

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Answer 1

$\huge\underline \bold{Solution}$

i] An elevator descends into a mine shaft at the rate of 5 metre per minute . What will be its position after one hour?

•As given in the question,the elevator is going down, So,the distance covered by the elevator will be represented by a negative integer.

• Change in the position of the elevator in one minute = -5m .

= Position of the elevator after 60 minutes =(-5) × 60 = -300m below.

That is 300m below down from the starting position of elevator .

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ii] If it begins to descend from 15m above the ground,what will be its position after 45 minutes ?

•Change in position of the elevator in 45 minutes = (-5) × 45 = 225 m .

• That is 225 m below ground level.

So,the final position of the elevator = -225 + 15 = -210m .

• That is 210 m below ground level.

$\sf\orange{Done!}$

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