PLEASE HELP ASAP Joe, a hiker, stands at the top of a hill on a trail above the ocean. Joe's friend Dave is just starting out at the
trailhead, which is at the beach.
Which statement about this scenario is accurate?
O The air Joe is breathing is denser than the air at sea level.
O The air pressure is higher where Joe is than where Dave is.
O If Joe keeps going up, air pressure will continue to decrease,
O The air Joe is breathing is denser than the air Dave is breathing,

Prompta snowboarder stands at the top of a hill and decides to see if he can increase his speed on his next trip down the slope.describe one thing the snowboarder could do to incrlase his speed on the slope. explain why this would cause his speed toincrease relate one of newton's laws to this problem.

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.

When is a current produced? when the terminals of an electrochemical cell are connected by a wire if the electric circuit is opened in an electrochemical cell if the electrolyte is removed from an electrochemical cell when the electrodes are reversed in an electrochemical cell