Question 7
A cylinderical roller 2.5 m in length, 1.75 m in radius when rolled on a road was found to cover the area of 5500 m2. How many revolutions did it make?
Given, length of the cylindrical roller, h = 2.5 m
Radius of the cylindrical roller, r = 1.75 m
Total area rolled on a road by cylindrical roller =5500 m2
∴ Area rolled in one revolution = Curved surface area of the cylindrical roller
=2πrh=2×227×1.75×2.5
=44×4.3757=192.57=27.5 m2
∴ Number of revolutions rolled by a cylindrical roller
=Total area rolled by cylindrical rollerArea rolled in one revolution=550027.5=200