Question

A solid is composed of a cylinder with hemispherical ends. If the whole length of the solid is 104 cm and the radius of each of the hemispherical ends is 7 cm, find the cost of polishing its surface at the rate of Rs 10 per dm² .

Answer 1

We have a solid composed of cylinder with hemispherical ends.

Radius of the two curved surfaces

Height of cylinder is h.

Total height of the body

So, total surface area is given by,

Change the units of curved surface area as,

Cost of polishing the surface is Rs 10 per.

So total cost,