Two masses are placed close to each other. How will the gravitational force acting on the masses change if the distance between the two masses is doubled?

The slope of a good speed time indicates ? a. velocity b. acceleration c. direction d. speed

Which of these has some mechanical energy? a. an atom b. heat inside earth c. a book on a shelf d. the fire from a lit match

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*