1. The problem statement, all variables and given/known data A punch is used for cutting an (approximately) circular hole with a diameter of 35 mm through a metal sheet 0.2 cm thick. If the shear strength of the metal is 80 MPa, estimate the force needed to punch the hole. Make it clear how you have calculated this value. 2. Relevant equations Unsure... 3. The attempt at a solution I know this is properties of solid materials but would it be Hooke’s Law, modulus of elasticity; tension and compression; stress-strain relations for longitudinal and shear stress; elastic limit; ultimate strength; comparison of metals, polymers and ceramics as engineering materials in relation to density, strength, thermal, electrical or magnetic properties? I think ultimate strength and comparison of metals with perhaps stress / strain relevance also?