Pls pls help will b forever grateful A student does an experiment to compare the potential energy of a block sliding down a ramp. He calculates the gravitational potential to be 150 J. However, the kinetic energy at the bottom was calculated to be ONLY 100 J. Why wasn't energy conserved in this situation?

Question 6 options:

The car's weight increased as it slided down the ramp.

The student pushed the car at the top rather than releasing it from rest.

The student gave an incorrect measurement for the ramp that was too BIG.

The student did NOT account for the friction converting some of the object's kinetic energy into heat.

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.