In the novel return from the stars by s. lem, which is concerned with the problems a returning twin in the twin paradox situation might face, there is the following passage "her eyes were shining and attentive: i was thirty then. the expedition i was a pilot on the expedition to fomalhaut. that’s twenty-three light years away. we flew there and back in a hundred and twenty years ship time. four days ago we returned . . the prometheus—my ship — remained on luna. i came from there today. that’s all." assuming that all accelerations are instantaneous and the velocity of the prometheus was constant in between, with what speed did it travel from the earth to fomalhaut

Steam is generated in a boiler of a cogeneration plant at 10 mpa and 450°c at a steady rate of 5 kg/s. in normal operation, steam expands in a turbine to a pressure of 0.5 mpa and is then routed to the process heater, where it supplies the process heat. steam leaves the process heater as a saturated liquid and is pumped to the boiler pressure. in this mode, no steam passes through a condenser, which operates at 20 kpa. (a) determine the power produced in the turbine and the rate at which process heat is supplied in this mode. (b) determine the power produced in the turbine and the rate of process heat supplied if only 60 percent of the steam is routed to the process heater and the remainder is expanded to the condenser pressure. (3.32 mw; 9.69 mw; 4.25 mw; 5.82 mw)

Calculate the work done by an external agent during an isothermal compression of 1.00 mol of oxygen from a volume of 22.4 l at 10∘c and 1.0 atm pressure to 16.8l

An initially unpolarized light if intensity 500 w/m^2 passes through four polarizers. the transmission axis between adjacent polarizers is 45∘. what percentage of the initial intensity is transmitted by the system?