(a) calculate the buoyant force (in n) on a 2.10 l helium balloon. (b) given the mass of the rubber in the balloon is 1.10 g, what is the net vertical force (in n) on the balloon if it is let go? you can neglect the volume of the rubber.

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.

70 give a real life example showing how sensory neurons work with the motor neurons

Which of the following is another term for a planned economy