A17.6-kg object oscillates at the end of a horizontal spring that has a spring constant of 20.0 kn/m. the effect of air resistance is represented by the damping coefficient b = 6.69 kg/s. find the time for the amplitude of the oscillation to drop to 5.98% of its original value.

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.

Clothes dryer uses about 7 amps of current from a 240 volt line. how much power does it use?

Who was the first scientist to measure speed as distance over time?