A single-start square-thread power screw has an input power of 3 hp at a speed of 2 rev/s. The screw has a major diameter of 2-in and a four threads per inch. The friction coefficients are 0.14 for the threads and 0.09 for the collar, with a mean collar diameter of 3-in. (a) Find the maximum load that the screw can lift. (Express your answer to the nearest lb).

(b) Also calculate the efficiency of the screw.

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.

Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?

The thermal expansion or contraction of a given metal is a function of the f a)-density b)-initial temperature c)- temperature difference d)- linear coefficient of thermal expansion e)- final temperature f)- original length