Saved Bookmarks
| 1. |
The diameter of a roller is 84 cm and its length is 120 cm. It takes 500 completerevolutions to move once over to level a playground. Find the area of the playgroundin `m^2`. |
|
Answer» We have, diameter of a roller = 84 cm r = radius of a roller = 42 cm h = 120 cm To cover 1 revolution = curved surface area of roller `= 2pi rh` `=2xx(22)/(7)xx42xx120 cm^(2)` `=44xx720 cm^(2)=31680 cm^(2)` `=(31680)/(100xx100)m^(2)=3.168 m^(2) " " (because 1m =100 cm)` Area of the playground = takes 500 complete revolutions `= 500xx3.168 m^(2)=1584 m^(2)` |
|