Carlos uses one golf ball to set another golf ball in motion. The following diagram shows how Carlos designs his experiment .Carlos releases the ball on the string from different heights. Each time, the first ball strikes the second ball, which then rolls down the track. Which force causes the first ball to swing downward?

a pull due to gravity

a pull from the string

a push from Carlos’s hand

friction between air and the golf ball

Which instrument is used to measure air temperature

According to newtons universal law of gravitation, which would change the parh of the ball so it traces out widest curved path possible?

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.