E2 Quiz A cart is speeding up along a track. What can we inter about the cart's kinetic (or motion) energy?
We can infer that the cart's kinetic (or motion) energy is increasing.
We can observe that the cart's kinetic (or motion) energy is increasing.
We can see that the cart's kinetic (or motion) energy is increasing.
We cannot say anything about the cart's kinetic (or motion) energy.

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.

An object weighs 40n in air, weighs 20n when submerged in water and 30n when submerged in a liquid of unknown density. what is the density of the liquid?

Wavelength of 125 meters is moving at a speed of 10 m/s. what is it's frequency?