HELP William writes the following description of how objects are attracted to each other.

Charges transfer from one object to another. A charged object next to an uncharged object will repel each other. A positively charged object and a negatively charged object will attract each other.

What is the error in William's description?

A charged and uncharged object attract each other.
Charges are transferred from water to objects.
Transfer of charges occurs due to heat.
Two charged objects attract each other.

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*