An uncoated, solid cable of length l = 1 m and diam- eter d = 40 mm is exposed to convection conditions characterized by h = 55 w/m2⋅k and t[infinity] = 20°c. determine the maximum electric current that can be carried by the cable if it is pure copper, pure aluminum, or pure tin. calculate the corresponding minimum wire temperatures. the electrical resistivity is rhoe = 10 × 10−8 ω ⋅ m for copper and aluminum at their melting points, while the electrical resistivity of tin is rhoe = 20 × 10−8 ω ⋅ m at its melting point.

Amass of 1.5 kg of air at 120 kpa and 24°c is contained in a gas-tight, frictionless piston-cylinder device. the air is now compressed to a final pressure of 720 kpa. during the process, heat is transferred from the air such that the temperature inside the cylinder remains constant. calculate the boundary work input during this process.

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

Water in a partially filled large tank is to be supplied to the roof top, which is 8 m above the water level in the tank, through a 2.2-cm-internal-diameter pipe by maintaining a constant air pressure of 300 kpa (gage) in the tank. if the head loss in the piping is 2 m of water, determine the discharge rate of the supply of water to the roof top in liters per second.