Amusement Park Physics You've studied the motion of a snowboarder in the previous section and analyzed how potential and kinetic
energy changes throughout that motion. Let's mix in a little more fun with our physics.
Imagine a roller coaster ride at an amusement park. As you might guess, a roller coaster is not all thrilling
adventure; there's probably a lot of physics involved too. Based on your analysis of the snowboarder's motion,
answer a few questions about a roller coaster.
Part A
Assuming a nearly frictionless ride, what can you say about a roller coaster's potential and kinetic energy from
the top to the bottom of a hill?
B Ių x x Font Sizes А • А DE

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.

What causes the formation of ocean currents?

During the experiment if you could triple the breakaway magnetic force with all other quantities left unchanged, what is the new value for the critical velocity if it was v0 (initial velocity), initially? (b) now if you halved the radius with all other quantities left unchanged, what is the new critical velocity if it was v0 (initial velocity), initially? (c) if during the experiment, critical velocity quadrupled with all other quantities left unchanged, what is the new breakaway force if its magnitude was initially f0,?