Q1)A steel drum, with 0.524 m outside diameter and 0.486 m inner diameter, is to be mounted in a machine and spun about its longitudinal axis (of symmetry). The hoop stress induced in the cylinder is not to exceed 83 MPa. Determine the maximum speed at which the drum can be rotated. Take = 0.27 and = 7860 kg/m3 .

Q2)An internal combustion engine has a cast iron flywheel that could be considered as a uniform thin disc. This flywheel was found to yield when it rotates with a speed of 9129 RPM. Determine the maximum stress that would be induced in this disc if a maximum permissible speed of 6054 RPM was allowed (elastic deformation). Assume the following properties for the cast iron: = 7180 kg/m3, = 200 MPa and = 0.25.