Molecular Physics | Thermodynamics Answers

each group of solar cells is arranged in a rectangle 1.2 mx2.8m.the solar cells are situated in a region where 260w of solar energy is recieved per square m of the cells ,the electric output of each group of solar cells is a current of 2.5 with a potential difference of 86v.calculate teh efficency of the solar cells

A woman weighing 75 kg stands on a spring scale in elevator. During the first 3 seconds of motion from rest, the tension T in the hoisting cable is 8300 N. The total mass of the elevator , woman scale is 750 kg.

1.Find the vertical acceleration of the elevator.

2.Find the reading R of the scale in Newtons during this interval.

3.Find the upward velocity of the elevator at the end of a 3 seconds.

Three indistinguishable particles are to be distributed in two cells. Find possible number of

macrostates and corresponding number of microstates.

An ideal gas expands isothermally,performing 3.40×10³ J of work in the process.Calculate the change in internal energy of the gas and the heat absorbed during this expansion.

A 10-ft³ vessel of hydrogen at a pressure of 305 psia is vigorously stirred by paddles until the pressure becomes 400 psia. Determined (a) ∆U,and (b) W. No heat is transferred, cv= 2.434 Btu/lb.R

A reversible, nonflow, constant volume process decreases the internal energy by 316.5kJ for 2.268 kg of gas for which R= 430 J/kg.K and k= 1.35. For the process, determimed

(a) the work, (b) Q, and (c) ∆S. The initial temperature is 204.4°C.

A perfect gas has a value of R=58.8ft.lb/lb.R and k=1.26, If 20 Btu are added to 5lb of this gas at constant volume when the initial temperature is 90°F, find (a) T₂, (b) ∆H, (c) ∆S, (d) ∆U and (e) work of non flow process.

One liter of air is cooled at constant pressure until its volume is halved, and then is

allowed to expand isothermally back to its original volume. Draw the process on

the PV diagram.

An ideal gas expands isothermally, performing 3.40x103 J of work in the process.

Calculate (a) the change in the internal energy of the gas, and (b) the heat

absorbed during the expansion.

In an ideal rankine cycle, steam is generated at 4.1 MPa and 480 degrees C. The condenser is at 32 degrees C. Determine (a) The ideal pump work. (b) The cycle thermal efficiency, (c) For an engine with the same end states, determine its thermal efficiency, steam rate, and map, (d) considering the engine only, assume the brake engine efficiency to be 78%, the generator efficiency to be 92%, the steam flow rate 163,300 kg/hg; compute the output of the combined unit.