Question

If bending moment on point B in horizontal plate is M and in vertical plane is m, then the net bending moment at point B is?

(a) M

(b) m

(c) M+m

(d) √M²+m²

This question stumped me in my study session.

This fundamental question comes from the Shaft Design in lesson Shafts, Keys and Couplings of Machine Design

Answer 1

The recommended answer is (d) √M²+m²

Breaking it down, I'd say: The two moments act perpendicularly to each other.