Polarized light is incident on 7 polarizing sheets. the axis of the first polarized sheet makes an angle θ with the plane of polarization. each subsequent sheet has an axis that is rotated by an angle θ from that of adjacent sheets. find θ if 92% of the incident intensity is transmitted by the sheets. ° suppose you want to rotate the plane of polarization of a beam of polarized light by 65°, but you do not want the final intensity to be < 66% of the initial intensity. what is the minimum number of polarizing sheets you must use? sheets

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.

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.

Which best describes the difference between internal and thermal energy?