A cantilever beam has the square cross section of 10 mm

A cantilever beam has the square cross section of 10 mm × 10 mm. It carries a transverse load of 10 N. Considering only the bottom fibres of the beam, the correct representation of the longitudinal variation of the bending stress is

Here , I =	bh³	=	0.01 × 0.01³	m⁴
	12		12

y = 0.005 m

At left extreme of cantilever
σ_bending = 60 × 1 MPa = 60 MPa after 1 m
σ_bending = 60 × 0 MPa = 0 MPa and it will continue over whole span.

σ_{(bending stress)} =	Mxy	=	(10x)(0.005)	N / m²
	I		(0.01)⁴ / 12

σ_bending = 60 x MPa (straight line equation)