Question

An aeroplane was flying at a height of 1600m .From the time it started to land, it made a change of 70m in every minute. How many minutes will it take to descend to a height of 200m?

Answer 1

Hint: Here it is given that the aeroplane is initially at a height of 1600m. But then it starts descending.
So we have to find the distance it descends and then calculate the time required.

Complete step-by-step answer:
Given that, an aeroplane was flying at a height of 1600m.
Now it has started landing but it covers a distance of 70m per minute.
And we have to find the time it takes to descend to a height of 200m from ground. So total distance it covered in the landing is ,
\[1600 - 200 = 1400\]
So now we have the distance covered and the speed also .So let's find the time.
Time taken \[ = \dfrac{{dis\tan ce}}{{speed}}\]
\[ \Rightarrow \dfrac{{1400}}{{70}}\]
\[ \Rightarrow 20\min utes\]
So the time taken by aeroplane is 20minutes.

Note: In this situation a student can get confused about where to consider those 200m. So we have to consider it from ground .That means the aeroplane has covered 1400m and the rest 200m are from ground. We have to calculate the time it took to cover those 1400m.