Assume that the surface roughness profile is triangular as shown schematically in the figure. If the peak to valley height is $$20$$ $$\mu m$$ The central line average surface roughness $${R_a}$$ (in $$\mu m$$) is

Circular arc on a part profile is being machined on a vertical $$CNC$$ milling machine. $$CNC$$ part program using metric units with absolute dimensions is listed below:

$$\eqalign{ & N60\,\,\,\,G01\,\,\,\,X\,30\,\,\,\,Y\,55\,\,\,\,Z\,5\,\,\,\,F50 \cr & N70\,\,\,\,G02\,\,\,X\,50\,\,\,\,Y\,35\,\,\,\,R\,20 \cr & N80\,\,\,\,G01\,\,\,\,Z\,5 \cr} $$

The coordinates of the center of the circular arc are:

In the engineering stress-strain curve for mild steel, the Ultimate Tensile Strength $$(UTS)$$ refers to

The Poisson's ratio for a perfectly incompressible linear elastic material is