3000 kg of water is heated per hour from 30 to 70 0C by pumping it through a certain heated section of a 25 mm diameter tube. If the surface of the heated section is maintained at 110 0C, estimate length of the heated section and the rate of heat transfer from the tube to water. The thermo-physical properties of water are: rho = 971.6 kg/m3 ; μ = 0.355 x 10-3 kg/m-s; k = 0.667 W/m-deg; Cp = 4195 J/kg-deg. Use Nu = 0.023 (Re) 0.8 (pr) 0.4

An electrical motor raises a 50kg load at a construct velencity .calculate the power of the motor, if it takes 40sec to raise the load through a height of 24m(take g =9.8n/g)

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.

The higher the astm grain size number, the finer the gran is. a)-true b)-false