Suppose you have a box. Which of these is NOT necessarily a TRUE statement regarding the relationship between the force applied to the box, the work done on the box, and the distance the box is moved? A. If the box is not moved, no force is being applied to the box. B. If no force is applied to the box, no work is done on the box. C. If work is done on the box, then a force is applied to the box. D. If work is done on the box, then the box is moved a distance.

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.

Find v(t), given acceleration a(t)=7j and initial velocity v(0)=k

Use the information presented in the graph to answer the questions. which segments show acceleration? which segment indicates that the object is slowing down? what is the velocity of segment b? what is the acceleration of segment b?