A hydroelectric dam generates power when water held within it is released through a turbine located at the base of the dam. The water at the surface of the dam is at temperature T1 and pressure P1. The water exits the turbine at temperature T, and pressure pa with mass flow rate m. Assume that water is incompressible fluid with constant specific heat c. The water is intially at height z. The entropy generated during this process is σ. Kinetic energy effects at all given states can be ignored. Given p1 =1 bar, =13 kg/s, z=136 m, T2 =30 °C, T, =30.22 °C, P2 =1 bar, c=4.18 kJ/kg-K

Required:
Determine the rate of entropy generation

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2

Shafts are machine elements that are used to a) carry axial loads b) direct shear loads c) transmit power d) rotate at constant speed e) none of the above circular and square shafts subjected to the same torque under the same circum behave a) the same way b) almost the same way