Afatigue test was conducted in which the mean stress was 90 mpa (13050 psi), and the stress amplitude was 190 mpa (27560 psi). (a) compute the maximum stress level. entry field with correct answer 280 mpa (b) compute the minimum stress level. entry field with correct answer -100 mpa (c) compute the stress ratio. entry field with correct answer -0.36 (d) compute the magnitude of the stress range.

Amass of 1.5 kg of air at 120 kpa and 24°c is contained in a gas-tight, frictionless piston-cylinder device. the air is now compressed to a final pressure of 720 kpa. during the process, heat is transferred from the air such that the temperature inside the cylinder remains constant. calculate the boundary work input during this process.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?