a) Draw a picture of the system. b) Name an extensive property that can be count

Question

a) Draw a picture of the system.

b) Name an extensive property that can be counted.

c) Label the system, surroundings, and system boundary.

d) State the time period of interest. Justify.

e) Identify the system as open closed or isolate and sate why

f) Identify the system as a steady-state or dynamic and state why.

g) Identify whether the system has a reaction and/or energy interconversion and state why.

h) Should an algebraic, differential, or integral equation be used to describe the system? State why.

i) Is the selected extensive property conserved in this system? State why.

2.6 (E) A calorimeter can determine a person's metabolic rate by measuring the quantity of heat liberated from the body in a given period of time. The calorimeter consists of a large air chamber with well-insulated walls that prevent energy transfer into or out of the calorimeter. As the person's body produces heat, a constant air temperature in the chamber is maintained by forcing the air through pipes in a cool water bath. A thermometer measures the temperature increase, which is used to calculate the rate of heat gain by the water bath, which equals the rate of heat release from the person's body. You want to measure your metabolic rate as you exercise in the calorimeter.

Explanation / Answer

2.6 diagram of our system in the problem

b. the extensive property that can be counted is heat

c. as labelled in the diagram

d. time period os interest is the time at which the experiment begins tot he time which experiemnt ends

as in this time we will find out how much person consumes ( energy n terms of metabolic rate) and spends as well under all kinds of supervision to get accurate results

also, cumulative effects of past can be ignored if the experiment is conducted again and again

e. tyhe system is not closed ( as air leAVEs the system into water bath)

but the system is isolated ( as the energy which leaves the system is accounted for in the water bath)

f. the system is a dynamic state system which shall turn towards steady state system as the experiment progresses

as if we assume the person's power output is constnat

if we dont assume this, then the system is a dynamic state system as we have no idea of the person's metabolic rate

g. the system has a reaction/interconvertsion state where the the chemical energy inside the human body is converted into thermal energy and the enrgy required for the metabolism of the body

h. as the system is a constant temperature system, and the water bath is accumulating energy dissipated by the body over time, we can use integral form of equation over time to say that total energy in the controlvolume over a period of time is constant, and its differentiation will be 0

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