Ex.1.4 Q7 Integers Solution - NCERT Maths Class 7

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Question

An elevator descends into a mine shaft at the rate of \(6 \text{ m/min}\). If the descent starts from \(10\;\rm{m}\) above the ground level, how long will it take to reach \(-350\;\rm{m}\)?

 

Text Solution

Steps:

  Total distance covered by an elevator 

\[\begin{align}& =10-(-350)\text{m} \\  & =10+\left( 350 \right) \\  & =360\,\text{m}  \end{align}\]

So, time taken to cover a distance of \(6 \rm{m}=1\) min

Therefore, time taken to cover \(360 \text{ m}\)

\[\begin{align}&=\text{ 360  }\!\!\div\!\!\text{  6 } \\  & =\text{ 60}\,\text{minutes}  \end{align}\]

(\(1\) hour \(= 60\) minutes)

Thus, the elevator will reach \(–350\;\rm{m}\) from \(10\;\rm{m}\) in \(1\) hour.

  
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