To practice problem-solving strategy 30.1: inductors in circuits. a circuit has a 1 v battery connected in series with a switch. when the switch is closed, the battery powers two paths in parallel, one of which has a resistor of resistance r1 = 95 ω in series with an inductor of inductance l = 1.5×10−2 h , while the other has a resistor of resistance r2 = 360 ω . what is the current supplied by the battery at a time t = 0.4 ms after the switch is closed?

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies.

If it takes a planet 2.8 x 10^8 s to orbit a star with a mass of 6.2 x 10^30 kg what is the average distance between the planet and the star

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.