Jessica did an investigation about the states of matter. As part of the investigation, Jessica wanted to change a liquid into a solid. What must she do to bring about this change in state? place the liquid in a different container
A
B
stir the liquid as quickly and thoroughly as possible
C
remove energy from the liquid so that its particles slow down
D
increase the energy of the liquid so that its particles move faster

Asteel tube (k=50 w/mk) of inner and outer diameter di = 20mm and do=26mm, respectively, is used to transfer heat from hot gases flowing over the tube (h-hot = 200w/m2k) to cold water flowing through the tube (h-cold = 8000 w/m2k). what is the cold-side overall heat transfer coefficient uc? to enhance heat transfer 16 straight fins of rectangular profile are installed longitudinally along the outer surface of the tube. the fins are equally spaced around the circumference of the tube, each having a thickness of 2mm and a length of 15mm. what is the corresponding overall heat transfer coefficient uc? *solve for uc in both cases*