A round solid bar having a groove of 0.1-in deep with a 0.1-in radius machined into it. The material of the bar is AISI 1020 cold drawn steel, its diameter is 2.54 cm, and it is exposed to a
purely reversing torque of 1800 lbf. in. For the S-N curve of such material, take f = 0.9.
(a) Estimate the number of cycles to failure.
(b) If the bar is also placed in a 750◦F environment, estimate the number of cycles to failure.

Avolume of 2.65 m3 of air in a rigid, insulated container fitted with a paddle wheel is initially at 264 k, 5.6 bar. the air receives 432 kj by work from the paddle wheel. assuming the ideal gas model with cv = 0.71 kj/kg • k, determine for the air the amount of entropy produced, in kj/k

What are the major differences between injection molding and extrusion?

Tom is having a problem with his washing machine. he notices that the machine vibrates violently at a frequency of 1500 rpm due to an unknown rotating unbalance. the machine is mounted on 4 springs each having a stiffness of 10 kn/m. tom wishes to add an undamped vibration absorber attached by a spring under the machine the machine working frequency ranges between 800 rpm to 2000 rpm and its total mass while loaded is assumed to be 80 kg a) what should be the mass of the absorber added to the machine so that the natural frequency falls outside the working range? b) after a first trial of an absorber using a mass of 35 kg, the amplitude of the oscillation was found to be 10 cm. what is the value of the rotating unbalance? c) using me-3.5 kg.m, find the optimal absorber (by minimizing its mass). what would be the amplitude of the oscillation of the absorber?