Question

The thickness of a hollow metallic cylinder is 2 cm It is 70 cm long with radius of 14 cm find the volume of the metal used in making the cylinder assuming that it is open at both the ends also find its weight if the matter with 8 gram per centimetre cube

Answer 1

First find out outer area , then find inner area of the circle face of the cylinder

and then subtract latter from the former .

Area of outer circle = πr²

                               = 3.14 * 14 * 14

                               = 615.44

Area of inner circle (Radius = 14-2=12)

                                =πr²

                                = 3.14 * 12 * 12

                                 =  452.16

Difference = 615.44 - 452.16

                  = 163.28

Volume = difference * length

            = 163.28 * 70

            =  11429.6