Circular copper rods of diameter d=1mm and length l=25mm areused to enhance heat transfer from a surface that is maintained atts,1=100 deg. c. one end of the rod is attached tothis surface (at x=o), hile the other end (at x=25mm) is joined toa second surface that is maintained at ts,2=0deg. c. air flowing between the surfaces (and over the rods)is also at a temperature t? = 0 deg. c, and has a convectioncoefficient of h=100 w/m2kelvin.

a. what is the rate of heat transfer by convection from a singlecopper rod to air?
b. what is the total rate of heat transfer from a 1 m x 1 m section of the surface at 100 deg. c, if a bundle of the rods is installed on 4-mm centers?

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Heat is added to a piston-cylinder device filled with 2 kg of air to raise its temperature 400 c from an initial temperature of t1 27 cand pressure of pi 1 mpa. the process is isobaric process. find a)-the final pressure p2 b)-the heat transfer to the air.

Asingle-geared blanking press has a stroke of 200 mm and a rated capacity of 320 kn. a cam driven ram is assumed to be capable of delivering the full press load at constant force during the last 15 percent of a constant-velocity stroke. the camshaft has an average speed of 90 rev/min and is geared to the flywheel shaft at a 6: 1 ratio. the total work done is to include an allowance of 16 percent for friction a) estimate the maximum energy fluctuation b) find the rim weight for an effective diameter of 1.2 m and a coefficient of speed fluctuation of 0.10