Can anyone please answer the 20thquestion ? And please explainthe answer with proccedure
Hello Atchaya Meena dear, the total number of revolutions will be got by getting the area under the curve.
Now there are three portions
One triangle with height (2400-600) rev/m and base 8 s ie 8/60 min
Next one is a rectangle with length 8/60 min and breadth 600
Third another triangle with base 16/60 min and height 600
So total area = 1/2 * 1800 * 8/60 + 8/60 * 600 + 1/2 * 16/60 * 600 = 120 + 80 + 80 = 280
So option 2 is the right one
Now there are three portions
One triangle with height (2400-600) rev/m and base 8 s ie 8/60 min
Next one is a rectangle with length 8/60 min and breadth 600
Third another triangle with base 16/60 min and height 600
So total area = 1/2 * 1800 * 8/60 + 8/60 * 600 + 1/2 * 16/60 * 600 = 120 + 80 + 80 = 280
So option 2 is the right one