In the designation of wrought al alloys, eg. 3m, what does the first digit-3- refer to? a. the main alloying element b. carbon percentage of the alloy c. whether it is an ingot or a billet d. specific alloy heat treatment

Vibration monitoring this technique uses the noise or vibration created by mechanical equipment and in seme cases by plant systems to detemine their actual condtion. a)- true b)- false

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]

Determine the damped natural frequencies and the steady state response of a decoupled damped forced two degrees of freedom system. 10ä1 + 2q1 20q1 10 cos t; 10q2 +4q2 + 40q2 10 cos t