Consider a tie-rod that needs to support a force of 10.0 kN without fracture. Engineers are considering three different materials for this application; an advanced steel with a fracture-toughness of 120.0 MPa.m1/2 and density of 7.80 g/cm3, an aluminum alloy with a fracture-toughness 28.0 MPa.m1/2 and density of 2.70 g/cm3 and a magnesium alloy with a fracture-toughness of 15.0 MPa.m1/2 and density of 1.74 g/cm3. Which of these materials will result in the lightest tie-road that can sustain the above force? [Hint: The length of the rod is the same for all materials, but the diameter may be different. You may also assume that all three materials contain identical cracks. Y=1.00] The Mg Alloy. The steel. The Aluminum Alloy. They all result in the same mass of the tie-rod.