Consider a 2.54-cm-diameter power line for which the potential difference from the ground, 19.6 m below, to the power line is 115 kV. Find the line charge density on the power line. Wolfson, Richard. Essential University Physics, Volume 2 (p. 431). Pearson Education. Kindle Edition.

Which type of current is produced by a wire breaking magnetic field lines and changing the polarity? a. alternating b. direct c. straight d. alternating and direct

As part of an industrial process, air as an ideal gas at 10 bar, 400k expands at steady state through a valve to a pressure of 4 bar. the mass flow rate of air is 0.5 kg/s. the air then passes through a heat exchanger where it is cooled to a temperature of 295k with negligible change in pressure. the valve can be modeled as a throttling process, and kinetic and potential energy effects can be neglected. (a) for a control volume enclosing the valve and heat exchanger and enough of the local surroundings that the heat transfer occurs at the ambient temperature of 295 k, determine the rate of entropy production, in kw/k. (b) if the expansion valve were replaced by an adiabatic turbine operating isentropically, what would be the entropy production? compare the results of parts (a) and (b) and discuss.

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island