question_answer 30)

An elevator descends into a mine shaft at the rate of 6m / min. If the descent starts from 10 m above the ground level, how long will it take to reach \[-\text{ 35}0\text{ m}\].

Answer:

                Let \['x'\] minutes be the time taken to reach \[-350\,m\]. According to the question, we get \[x=\frac{(-10)+(-350)}{6}=\frac{-360}{6}=-60\] Negative sign indicates descent. \[\therefore \]  \[x=\text{6}0\]minutes = 1 hour..