Mensuration-2

From Homeworkwiki

A cylindrical tank has a capacity of 6160 cu. m. Find its depth if the diameter of the
base is 28 m. Also calculate the cost of painting its inside curved surface at the rate of of $ 5 per sq meter.

Solution: Diameter of the base = 28 m

Therefore, radius of the base = 28/2 = 14 m

Let h meters be the height of the tank.

Volume of the tank = 6160 m³

π r² h = 6160

22/7 x 14² x h = 6160

616h = 6160

h = 10 m

Curved surface area = 2 π r h

= 2 x 22/7 x 14 x 10 = 880 m²

Cost of painting its inside surface at the rate of $ 5 per sq. m

= $ 880 x 5 = $ 4400