Mensurationhard · Past Paper
A cylinder of radius r and height h is exactly the same surface area as a cube of side s. Find s in terms of r and h.
Asqrt(πr(r+h)/3)
Bsqrt(2πr(r+h)/3)
Csqrt(πr(r+h)/6)
Dsqrt(2πr(r+h)/6)
✓ Correct Answer: A — sqrt(πr(r+h)/3)
6s² = 2πr(r+h) => s² = 2πr(r+h)/6 = πr(r+h)/3 => s = sqrt(πr(r+h)/3).
Share this question
More from Mensuration
- A cylindrical tank has a capacity of 6160 cubic m. If its depth is 10 m, find the cost of painting its inner curved surface at Rs. 2.50 per sq. m.
- The total surface area of a right circular cone is 90π cm². If its radius is 5 cm, find its slant height.
- Find the volume of a hollow cylinder with external radius 5 cm, internal radius 4 cm, and height 10 cm.
- How many times does the surface area of a sphere increase if its radius is tripled?
- A metallic sphere of radius 10.5 cm is melted and then recast into small cones, each of radius 3.5 cm and height 3 cm. Find the number of cones.