On a roller coaster loop-the-loop the riders are upside-down at the top of the loop, while on a ferris wheel the riders are upright at the top. suppose a ferris wheel and the loop of a roller coaster have the same diameter. if riders on each have the same magnitude of apparent weight at the top, which rider is moving faster? explain.

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*