4: Rafiq has 4 parking spaces in the basement of his apartment. Now, he wants to know when two adjacent space are open as he doesn’t not want anyone to park next to his
brand-new car. Rafiq already set up a pressure switches in the parking space to detect if the
space is occupied or not and also has 4 logic indicators outside his building. He wants one
logic indicator to activate if two adjacent space become open, another logic indicator to
active if three space become open, a third if all spaces are open and a fourth if one space is
open (in case he chooses to risk it).

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.

Abrake has a normal braking torque of 2.8 kip in and heat-dissipating cast-iron surfaces whose mass is 40 lbm. suppose a load is brought to rest in 8.0 s from an initial angular speed of 1600 rev/min using the normal braking torque; estimate the temperature rise of the heat dissipating surfaces.

The higher the astm grain size number, the finer the gran is. a)-true b)-false