Assume that a surface-grinding operation is being carried out under the following conditions: D = 250 mm D=250 mm, d = 0.4 mm d=0.4 mm, v = 0.5 m / s v=0.5 m/s, and V = 50 m / s V=50 m/s. These conditions are then changed to the following: D = 150 mm D=150 mm, d = 0.4 mm d=0.4 mm, v = 0.3 m / s v=0.3 m/s, and V = 25 m / s V=25 m/s. What is the difference in the temperature rise from the initial condition?

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.

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.