Final answer:
To find the shear strength, calculate the area where the force is applied using the bar's diameter, then determine shear strength using the formula shear stress equals force divided by area.
Step-by-step explanation:
To calculate the shear strength of the material being cut, we need to determine the cross-sectional area that the shear force is acting upon and then use the formula for shear stress which is τ = Force/Area. Given that the force required to cut the bar is 900 lb and the bar has a diameter of 0.400 in, we can find the area of a circle with radius r = diameter/2 using the formula for the area of a circle, A = πr2. Substituting the values into the formula, we find that the cross-sectional area A is π * (0.400 in/2)2 and then calculate the shear strength using the shear stress formula, τ = 900 lb / A.