You and your 3 friends are driving down the road. All the wheels go flat at the exact
same time, that's not good. You have to use a 2,100 N force to push the car 4 meters to the side of the road. How much work did you do on the car?
A. 525 J

B. 2,104 J

С. 8,400 J

D. zero work since the car broke down

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*