Question

A hollow cylinder open at both ends is made of steel 2 cm thick. What will be the volume of steel used in making the cylinder, if the external diameter is 24 cm and the length of the cylinder is 55 cm.

Answer 1

just compute the volume inside the metal and subtract it from the outside volume.

π/4 * 24^2 * 55 - π/4 * 20^2 * 51 = 2820π cm^3

Answer 2

If it is open at both ends, then the lengths are the same.

Volume of steel is obtained by subtracting the inner area from the outer area and multiplied by the length.

V=(π/4)(24²-20²)(55) cm³
= 2420π

Answer 3

My bad - I missed the fact that it was open on the ends.