Astudent conducts an experiment to determine how the additional of salt to water affects the density of the water. the student fills 3 beakers with equal amounts of water. he then adds 1 cup of salt to the first beaker, 2 cups of salt to the second beaker and no salt to the third beaker. what is the dependent variable in the student's investigation?

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*