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I am Lyosha [343]

3 years ago

13

A window‐mounted air‐conditioning unit (AC) removes energy by heat transfer from a room, and rejects energy by heat transfer to

the outside air. At steady‐state, the AC cycle requires 0.434kW and has a coefficient of performance (COP) of 6.22. Determine the rate at which the energy is removed from the room air, in kW. If electricity is valued at $0.10/kw-hr, determine the cost of operating the unit for 24hrs.

1 answer:

Arada [10]3 years ago

3 0

Solution :

Given :

The power of the air‐conditioning (AC) unit is , W = 0.434 kW

The coefficient of performance or the COP of the air‐conditioning (AC) unit is given by = 6.22

Therefore he heat removed is given by , $Q_H = 6.22 \times 0.434$

$Q_H = 2.7 \ kW$

Now if the electricity is valued at 0.10 dollar per kW hour, then the operating cost of the air conditioning unit in 24 hours is given by = 0.10 x 2.7 x 24

= 6.48

Therefore the operating cost = $ 6.48 for 24 hours.

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4 years ago

The manufacturer of a 1.5 V D flashlight battery says that the battery will deliver 9 mA for 40 continuous hours. During that ti

Jet001 [13]

Answer:

a) 144.000 s

b) and c)Battery voltage and power plots in attached image.

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Explanation:

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$m=\frac{1-1.5}{144000-0} = \frac{-0.5}{144000}$

where m is the slope.

$V-V_{1}=m(x-x_{1})$

where V is voltage in V, and t is time in seconds

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$V=-\frac{0.5}{144000} t + 1.5 V[tex] c) Using the equation VPOWER IS DEFINED AS:[tex] P(t) = v(t) * i(t) [tex]so.[tex] P(t) = 9mA * (-\frac{0.5}{144000} t + 1.5) [tex][tex]P(t) = - (31.25X10^{-9}) t + 0.0135$

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3 years ago

Determine whether or not it is possible to cold work steel so as to give a minimum Brinell hardness of 225 and at the same time

rodikova [14]

Answer:

First we determine the tensile strength using the equation;

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When the percentage of cold work for steel is up to 10,the ductility is 16% EL.

And 16% EL is greater than 12% EL

Therefore, it is possible to cold work steel to a given minimum Brinell hardness of 225 and at the same time a ductility of at least 12% EL

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2.24 Carbon dioxide (CO2) gas in a piston-cylinder assembly undergoes three processes in series that begin and end at the same s

Gekata [30.6K]

Answer:

Explanation:

Given that:

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For process 2 → 3

Since V is constant

Thus:

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The sketch of the processes on p -V coordinates can be found in the image attached below.

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