If you push a 900n refrigerator with the same force as you lift a 40n dumbbell, the dumbbell will move faster. which of newton’s laws is this an example of? explain how you know.

Heena wants to measure the volume of a ball that is 24 cm across. how should she set up her equation?

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.

Why is it important always to use horizontal bars in unit fractions when performing unit conversions?