the length of the roller is 40cm and its diameter is 21cm. it take 300 complete revolution to move once to level the floor of a room.find the area of the room in m square
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Convert all units to metre:
40 cm = 0.4m
21 cm = 0.21m
Find the radius:
Radius = Diameter ÷ 2
Radus = 0.21 ÷ 2 = 0.105 m
Find one revolution:
Area = 2πrh
Area = 2π(0.105)(0.4)
Area = 0.264 m²
Find 300 revolutions:
1 revolution =0.264 m²
300 revolutions = 0.264 x 300 = 79.2 m²
Answer: The area of the room is 79.2 m²
devdhanupapireddy:
the answer is 1.488
The area of the room is 4.158 m²also ans 1.488 is wrong
pi*r^2*h is the volume of a cylinder not surface area of the cylinder so check and then comment
the ans posted above 4.158m^2 or 1.488m^2 is wrong correct ans is79.2m ^2
check your ans first and comment or delete the ans next this will be better for other students who are seeking help from this platform
utkarashing4you before deleting others ans first check yours ans, this will be better for other students who are seeking help from this platform i hope you understand
Corrected.
@Debtwenty12pe7hvl, I apologise on behalf of the mod who accidentally deleted your answer. Sorry for all the misunderstanding. And your answer is great! :)
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hope this will help you
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