If you are a subcontractor in the leather and apparel industry, you might make any of the following items EXCEPT which

Refrigerant 134a enters a horizontal pipe operating at steady state at 40°C, 300 kPa, and a velocity of 25 m/s. At the exit, the

salantis [7]

Answer:

a) 2.42 $kg/s$

b) 37.20 m/s

c) 120.56 kW

Explanation:

Given that:

The fluid in the Refrigerant = R-134a

Diameter (d) = 0.1 m

In the Inlet:

Temperature $T_1 = 40^0C$

Pressure $P_1= 300kPa$

Velocity $V_1$ = 25 m/s

At the exit:

Temperature $T_2 = 90^0C$

Pressure $P_2 = 240 kPa$

From the Table A-12 for Refrigerant R-134a at $T_1 = 40^0C$ and $P_1= 300kPa$

Specific Volume $v_1 = 0.0809 m^3/kg$

From the Table A-12 for Refrigerant R-134a at $T_2 = 90^0C$ and $P_2 = 240 kPa$

Specific Volume $v_2 = 0.12038 kJ/kg$

Their corresponding Enthalpy $h_1$ and $h_2$ are as follows:

Enthalpy $h_1$ =284.05 kJ/kg

Enthalpy $h_2$ = 333 kJ/kg

a) The mass flow rate of the refrigerant can be calculated as :

$m_1 = \frac{AV_1}{v_1}$

$m_1 = \frac{\frac{\pi (0.1)^2}{4}*25}{0.08089}$

$m_1 = 2.42 kg/s$

b) The velocity at the exit point:

we knew that:

$m=m_1 =m_2$

∴

$\frac{AV_1}{v_1} =\frac{AV_2}{v_2}$

$V_2 = \frac{v_2}{v_1} V_1$

$V_2 = \frac{0.12038}{0.08089} *25$

$V_2 = 37.20 m/s$

c) Expression for calculating heat transfer (as long as there is no work that is said to be done and the pipe is horizontal) can be represented as:

$Q_{cv}= m[(h_2-h_1)+\frac{1}{2}(V_2^2-V_1^2)]$

$Q_{cv}= 2.42*[(333.49-284.05)+\frac{1}{2}(37.20^2-25^2)]$

$Q_{cv}= 2.42*[49.44+379.42]$

$Q_{cv}= 119.6448kW+918.19W(\frac{1kW}{1000W} )$

$Q_{cv}= 119.6448kW+0.92 kW$

$Q_{cv} = 120.56 kW$

3 0

3 years ago

(a) Design a first-order passive high-pass filter with a cutoff frequency of 1000 rad/sec.

balu736 [363]

Answer:

See the attachment

Verification shown in explanation

Explanation:

wc= 1/(RC)

The value of R and C shown in the attachment can be calculated as follows:

R=100 ohms

1000= 1/(100×C)

C= 10 microfarads

Gain= R/√(R²+Xc²)

at f=500, wc= 3142.59 rad/s

Xc= 1/(2πfC)

Xc=31.83

Gain= 100/√(100²+31.83²)

Gain= 0.953

at fc= 100, wc= 628.32 rad/s

Xc= 159.15

gain= 100/√(100²+ 159.15²)

gain= 0.532

As see form calculations that gain at low frequencies is smaller and gain at very high frequencies is near to 1. This means that at high frequencies Vin≈ Vout

Hence this filter allows high frequencies to pass but blocks low frequencies by lowering the gai

6 0

2 years ago

When you do a vehicle check, what do you NOT need to keep an eye on?

topjm [15]

Answer:

d

Explanation:

8 0

2 years ago

Select the correct answer.

steposvetlana [31]

Answer: Technical sales engineer

Explanation:

An analysis engineer makes use of data and other technical information in order for him or her to be able to analyze a project plan, and provide necessary solutions.

Technical sales engineers gives their clients the needed support and sales advice for their business to thrive. Technical sales engineers helps their clients in giving technical advices, answering queries, as well as introducing new products.

Design engineers are the engineers that study, and develop ideas that will be used for new products. Sometimes, they also modify systems used in production so that organizational performance can be improved.

Inspection engineers are the engineers that looks at infrastructures and identify the problems affecting them e.g oil pipelines, roads, bridges, etc so that accidents will be prevented.

Consulting engineer is an engineer that deals with the planning, and infrastructures. Their work benefits the society as a whole.

Based on the above explanation, the answer is technical sales engineer.

8 0

2 years ago

What is voltage drop?

lord [1]

Answer:

Explanation:

It is the voltage a voltmeter would read when connected across something that has resistance.

___________0_________O______O_______

| |

| | |

|_____________________| |_____________ |

|

The diagram above is supposed to represent 3 lightbulbs connected in series. The vertical lines in the middle are supposed to be a battery which powers the three light bulbs. If you put a voltmeter across one of the lightbulbs, it will read a voltage that is 1/3 of the voltage of the battery.

Answer

That reading you get across the one light bulb is The Voltage Drop.

6 0

1 year ago