Multiple choice

A road roller is in the shape of a cylinder. The radius of cross-section is 10.5 cm and the length is 1.5 m. What is the area covered by the roller in making 100 revolutions?

  1. 100 m2

  2. 99 m2

  3. 84 m2

  4. 75 m2

  5. None of these

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The area covered by the road roller in one revolution is its curved surface area.

So, area covered in 100 revolutions = 100 * 2πrh 

= (100 * 2 * 22 *10.5*1.5)/(7*100) 

= 99 m2