Q1. Brittle materials are normally classified such that (Choose one correct answer) Q2. The yield envelopes for two specific failure theories are shown in the figure for a plane stress condition. These theories assume that (Choose two correct answers) I. Materials have compressive strengths that are different to their tensile strea II. Materials have the same tensile and compressive strengths. III. They can be applied to ductile and brittle materials. IV. They can be applied to ductile materials. V. They can be applied to brittle materials. Q3. Brittle fracture may occur (Choose three correct answers) I. in ductile and brittle materials. II. only when applied stresses exceed the ultimate strength of the material. III. when applied loads are static or dynamic. IV. when the stress intensity factor is equal or greater than the fracture toughness of the material. Q4. There are no absolute rules for specifying the general layout of shafts, but the following guidelines may be helpiul: (Choose two correct answers) I. Pulleys and sprockets often need to be mounted between bearings for ease of installation of their belt or chain. II. It is necessary to transfer the loads in the shaft to the ground, which is usually achieved through a bearing system. III. It is necessary to provide torque-transfer elements to transmit the torque between the shatt and its mechanical components. IV. Notches are machined on shafts to provide a solid support to mechanical shafts' components and minimize their deflection and vibration. Answer the following question: L. Bending loads are usually very small at critical locations of rotating shafts where axial and torsion dominate. Yes II. It is necessary to consider the possibility of static failure of rotating shafts in their first load cycle. Yes No III. When the speed of rotating shafts approaches the shaft's natural frequency, the object begins to resonate, wh dramatically increases system vibration. Yes No