A cylinderical can is to be made to hold 1 litre of oil. Find the dimensions which will minimize the cost of the metal to make the can.

Of all the closed cylindrical cans (right circular), of a given volume of 100 cm^3 , find the dimensions of the can which has the minimum surface area?

Can a lens be used in the medium of which is is made of?

A container opened from the top and made up of a metal sheet, is in the form of a frustum of a cone of height 16 cm with radii of its lower and upper end as 8 cm and 20 cm, respectively. Find the cost of made which can completely fill the container, at the rate of Rs 20 per litre. Also find the cost of metal shape used to make the container, if it costs Rs 8 per 16cm^(2) . (Take pi=3.14 )

A metal of radius of 1 cm can not hold a charge of 1 coulomb. Why?

A container opened from the top is made up of a metal sheet is in the form of a frustum of a cone of height 16 cm with radii of its lower and upper ends as 8 cm and 20 cm, respectively. Find the cost of the milk which can completely fill the container, at the rate, of Rs 20 per litre. Also find the cost of metal sheet used to make the container, if it costs Rs 8 per 100 cm^2 . (Take pi = 3.14.)

A container, opened from the top and made up of a metal sheet, is in the form of a frustum of a cone of height 16 cm with radii of its lower and upper ends as 8cm and 20 cm, respectively. Find the cost of the milk which can completely fill the container, at the rate of ₹ 20 per litre. Also find the cost of metal sheet used to make the container, if it costs ₹8 per 100 cm^2 ( Take pi = 3. 14 )

An open metal bucket is in the shape of a frustum of a cone, mounted on a hollow cylindrical base made of the same metallic sheet (see Fig. 13.23). The diameters of die two circular ends of the bucket are 45 cm and 25 cm, the total vertical height of the bucket is 40 cm and that of the cylindrical base is 6 cm. Find the area of the metallic sheet used to make the bucket, where we do not take into account the handle of the bucket. Also, Find the volume of water the bucket can hold. (Take pi=22/7 ).