The Question. h t d A car strikes a rigid post at the centre of its bumper. The car is moving at a speed of v = 0.68 m/s and has a mass of m = 1650 kg. The bumper can be considered as a simply supported beam on two spring supports connected to the rigid frame of the car. The bumper is made of a polymer with young's modulus E-1.9 GPa. The cross-section of the bumper is shown in the figure to the right, with the relevant dimensions (not to scale): The cross-section of the bumper is shown in the figure to the right, with the relevant dimensions (not to scale): h = 260 mm d = 150 mm t = 3.6 mm The spring constant of each spring is k = 1.3 MN/m. The spring supports are located 21 = 1.6 m from each other, (and = 0.8 m from the point of impact). a) Calculate the relevant 2nd moment of area of the bumper I in 10. mm. Results are acceptable within a tolerance of 1 106.mm4. I : 10. mm (2 mark) b) Calculate the maximum deflection x in the bumper in mm. Results are acceptable within a tolerance of 0.1 mm. Enter a positive value. : mm (4 marks) b) Calculate the maximum theoretical stress max in the bumper in MPa. Results are acceptable within a tolerance of 0.1 MPa. Ignore the fact that this stress might be larger than the yield strength of the material. Enter a positive value, even if is the maximum compressive stress that has the larger absolute value. max MPa (4 marks)