The 8-mm-thick bottom of a 220-mm-diameter pan may be made from aluminum (k = 240 w/m ⋅ k) or copper (k = 390 w/m ⋅ k). when used to boil water, the surface of the bottom exposed to the water is nominally at 110°c. if heat is transferred from the stove to the pan at a rate of 600 w, what is the temperature of the surface in contact with the stove for each of the two materials?

Apiston-cylinder with a volume of 0.25 m3 holds 1 kg of air (r 0.287 k/kgk) at a temperature of 100 c. heat transfer to the cylinder causes an isothermal expansion of the piston until the volume triples. how much heat is added to the piston-cylinder?

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 power source in a certain welding setup generates 3500w that is transferred to the low carbon steel work with a heat transfer factor of 0.85. the melting factor in the operation is 0.45. a continuous fillet weld is to be made with a cross-sectional area of 23 mm2 determine the travel speed at which the welding can be accomplished.