You are provided with an epicyclic (planetary) gear train with the following 30, 20 and 70 teeth on the sun, planet and ring gear respectively. (a) draw a good sketch of this planetary gear train when viewed "along the axis" and "perpendicular to the axis' directions (b) what are the possible velocity ratios for this gear train? you can assume the ring gear will always be held constant.

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]