A hemishpherical tank is made up of an iron sheet 1 cm thick. If the inner radius is 1 m, then find the volume of the iron used to make the tank.

A hemispherical tank is made up of an iron sheet 1 cm thick. If the inner radius is 1m, then find the volume of the iron use to meke the tnak.

A hemispherical bowl made of steel, 0.25 cm thick. The inner radius of the bowl is 5 cm. Find the outer curved surface area of the bowl.

An oil funnel made of tin sheet consists of a 10 cm long cylindrical portion attached to a frustum of a cone. If the total height is 22 cm, diameter of the cylindrical portion is 8 cm and the diameter of the top of the funnel is 18 cm, find the area of the tin sheet required to make the funnel (see Fig ).

Rachel, an engineering student, was asked to make a model shaped like a cylinder with two cones attached at its two ends by using a thin aluminum sheet. The diameter of the model is 3 cm and its length is 12 cm . If each cone has a height of 2cm , find the volume of air contained in the model that Rachel made . ( Assume of outer and inner dimensions of the model to be nearly the same .

From the top of a cone of base radius 12 cm and height 20 cm. a small cone of base radius 3cm is to be cut off. How far down the vertex is the cuts should be made ? Find the volume of the frustum so obtained .

A conical tent is 10 m high and the radius of its base is 24 m. Find (i) slant height of the tent. (ii) cost of the canvas required to make the tent, if the cost of 1m^(2) canvas is Rs 70.