A  road roller has a diameter 0.7 m  and it's width 1.2m .Find the least number of revolutios that the roller must take in order to level a playground of size 120m ×44m

Asked by kk564025 | 3rd Feb, 2020, 08:45: PM

Expert Answer:

Diameter = 0.7 m 
Radius of the roller (r) = 0.7/2 = 0.35 m
Width of the roller (h) = 1.2 m
Curved surface area of the roller = Curved surface area of cylinder = 2 πrh
equals 2 cross times 22 over 7 cross times 0.35 cross times 1.2
equals 2 cross times 22 cross times 0.05 cross times 1.2
equals 2.64 space m squared

Area lavelled by roller = 120m x 44m = 5280 m2

N o. space o f space r e v o l u t i o n s space r e q u i r e d space equals space fraction numerator A r e a space l e v e l l e d space b y space r o l l e r over denominator C u r v e d space s u r f a c e space a r e a space o f space r o l l e r end fraction equals fraction numerator 5280 over denominator 2.64 end fraction equals 2000

Answered by Renu Varma | 4th Feb, 2020, 10:12: AM