An array of electronic chips is mounted within a sealed rectangular enclosure, and cooling is implemented by attaching an aluminum heat sink (k 180 w/m k). the base of the heat sink has dimensions of w1 w2 100 mm, while the 6 fins are of thickness t 10 mm and pitch s 18 mm. the fin length is lf 50 mm, and the base of the heat sink has a thickness of lb 10 mm. if cooling is implemented by water flow through the heat sink, with u 3 m/s and t 17c, what is the base temperature tb of the heat sink when power dissipation by the chips is pelec 1800 w

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

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?

The sum of the normal stresses does not change as the stress state rotates through an angle. a)-trune b)- false