The earth is 1.5 x 1011 m from the sun and takes a year to make one complete orbit. it rotates on its own axis once per day. it can be treated approximately as a uniform-density sphere of mass 6 x 1024 kg and radius 6.4 x 106 m (actually, its center has higher density than the rest of the planet, and the earth bulges out a bit at the equator). using this crude approximation, calculate the following. (a) what is vcm? m/s (b) what is ktrans? (c) what is w, the angular speed of rotation round its own axis? rad/s (d) what is krot? (e) what is ktot?

In which of the following cases is work being done on an object? question 2 options: pushing against a locked door carrying a box down a corridor pulling a trailer up a hill suspending a heavy weight with a strong

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 accounts for an increase in the temperature of a gas that is kept a constant volume