1. The problem statement, all variables and given/known data What force is required to punch a 20-mm-diameter hole in a plate that is 25 mm thick? The shear strength is 350 MN/m2. 2. Relevant equations σ = V / A 3. The attempt at a solution The first thing I did was rearrange the formula to isolate for V. I got the area which (A=πr2) gave me 314.15mm2. I change that to m and then I wne ahead and calculate the force which gave me 110.11 MN But the answer is 549.8 kN ( they multiplied 20x25xπ to get the area) Not sure where I am going wrong.