Which is true? earth. a. to see a total solar eclipse, you must travel to one particular small spot on b. from the penumbral part of earth's shadow, the sun is totally obscured c. at earth's poles, day and night are caused by earth's rotation. d. acceleration has units m's, and technically, the direction must also be given. e. the planets follow elliptical orbits with the sun at the center.

Eddy whose mass is 55kg climbs up the 1.50 meter high stairs in 2s.calculate eddy’s power rating

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.

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value