The magnitude of the tidal force between the international space station (iss) and a nearby astronaut on a spacewalk is approximately

2gmma/r3 . in this expression, m is the mass of the earth, r=6.79×106m is the distance from the center of the earth to the orbit of the iss, m=135kg is the mass of the astronaut, and a=13m is the distance from the astronaut to the center of mass of the iss.



calculate the magnitude of the tidal force for this astronaut. this force tends to separate the astronaut from the iss if the astronaut is located along the line that connects the center of the earth with the center of mass of the iss.

Order the sequence of ideas that lead to marie curies discovery of radioactive elements number the events in chronological order starting with the oldest

Your target variable is δf, the magnitude of the difference in frequency between the waves emitted from the sonar device and the waves received by the device after reflecting off the whale. write an expression for δf in terms of the relevant frequencies using the subscript notation introduced above.

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.