Question

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

Answer 1

Determine the time taken by the elevator to descend.

As we know that from the given information

The initial height of the elevator is $10\mathrm{m}$

The final depth of elevator is $–350\mathrm{m}$ [Here, distance descended is denoted by a negative integer]

Total distance to be descended by the elevator $=(-350)-(+10)=-360\mathrm{m}$

Time taken by the elevator to descend $-6\mathrm{m}=1\min$

Thus, time taken by the elevator to descend $-360\mathrm{m}=\frac{(-360)}{(-6)}$

= $60minutes$

= $1hour$

Therefore, the elevator takes $\mathbf{1}\mathbf{}\mathbf{hour}$ to descend.