In an IR detector, the sensor housing is held at 80 K by a mechanical cooler. The sensor is mounted to a frame that runs at 200 K by four thin walled hollow tubes that are 5.08 cm long by 1.27 cm outer diameter. The total heat leak through the four tubes into the detector has to be kept at less than 200 mW. Assuming G-10 (0.5 W/m-k) is used, find the wall thickness for the tube required to meet the heat leak condition. What if 6061-T6 (167.1 W/m-k) aluminum is used instead

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.

Water at 70°f and streams enter the mixing chamber at the same mass flow rate, determine the temperature and the quality of the exiting stream. 0 psia is heated in a chamber by mixing it with saturated water vapor at 20 psia. if both streams enters the mixing chamber at the same mass flow rate, determine the temperature and the quality of the existing system.

Burgers vector is generally parallel to the dislocation line. a)-true b)-false