In order to create a finned heat sink, an array of 10 rectangular fins, with a thermal conductivity of 100 W/mK, length 7 mm, and thickness 2 mm, are distributed equally along the top and bottom to a 60 mm long square fuel cell. the tips of the fins are adiabatic. the fuel cell operates at 375K. the contact joint between has the finned heat sink and the fuel cell has a thermal resistance of Rtc''=.01 m2K/W, the base of the heat sink is 5 mm thick. what is the net power (which is equal to the overall power generated by the fuel cell minu the power dissipated through the fin array) produced by the finned fuel cell system

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

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?