Question

The theorem of Pappus and Guldinus is used to find the ____________

(a) Surface area of the body

(b) Surface area of the body of revolution

(c) Surface area of the body of linear motion

(d) Surface area of the body of rectangular motion

This question was posed to me during an interview.

This key question is from Theorem of Pappus and Guldinus topic in section Centre of Gravity and Centroid of Engineering Mechanics

Answer 1

The correct answer is (b) Surface area of the body of revolution

To explain: The theorem is used to find the surface area and the volume of the revolving body. This is done by using simple integration. Thus the surface area and the volume of any 2D curve being rotated can be made to be calculated from this theorem.