An Important Question of M.L Aggarwal book of class 10 Based on Mensuration Chapter for ICSE BOARD.

A road roller (in the shape of a cylinder) having diameterand and its width.

Find the least number of revolutions that the roller must make in order to level a playground of given size in question. Give the solution of the question briefly.

This is the Question Number 06, Exercise 17.1 of M.L Aggarwal.

Deepak BoraNewbie

# A road roller (in the shape of a cylinder) has a diameter 0.7 m and its width is 1.2 m. Find the least number of revolutions that the roller must make in order to level a playground of size 120 m by 44 m.

Share

Given diameter of the road roller, d = 0.7 mRadius, r = d/2 = 0.7/2 = 0.35 mWidth, h = 1.2 mCurved surface area of the road roller = 2rh=2 ×(22/7)×0.35×1.2= 2.64 m^{2}Area of the play ground =l×b=120×44= 5280 m^{2}Number of revolutions = Area of play ground / Curved surface area= 5280/2.64= 2000Hence the road roller must take 2000 revolutions to level the ground.