Asiphon is a tube that exploits bernoulli's equation to move fluid around obstacles, to a lower elevation. one siphon is 2 cm in diameter and transfers fluid from a large reservoir to a 50 l bucket 2 m below the sur- face ofthe reservoir. the siphon travels upward initially, 20 cm above the reservoir surface, then downward to the bucket. along the tube, there is a pinhole at 10 cm below the reservoir's surface level. determine: (a) how long it takes to fill the bucket. (b) if water leaks out or air is drawn in at the pinhole. (c) if the uppermost bend in the siphon is safe from cavitation.

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w