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Sinks must be used for the correct intended purpose to prevent

irakobra [83]

Answer:

... spilling water or getting anything cascading onto the floor

8 0

2 years ago

A water supply agency is planning to add two reservoirs to its system. Water will flow from Reservoir A to Reservoir B via a 10,

NikAS [45]

Attached is the solution to the above question.

3 0

3 years ago

What oil specification is used to express the thickness (viscosity) of the oil?

Marianna [84]

Answer:

Viscosity is notated using the common classification “XW-XX”. The number preceding the “W” (winter) rates the oil's flow (viscosity) at zero degrees Fahrenheit (-17.8 degrees Celsius). The lower the number, the less the oil thickens in cold weather.

7 0

2 years ago

Air at 400kPa, 970 K enters a turbine operating at steady state and exits at 100 kPa, 670 K. Heat transfer from the turbine occu

Sonja [21]

Answer:

a

The rate of work developed is $\frac{\r W}{\r m}= 300kJ/kg$

b

The rate of entropy produced within the turbine is $\frac{\sigma}{\r m}= 0.0861kJ/kg \cdot K$

Explanation:

From the question we are told

The rate at which heat is transferred is $\frac{\r Q}{\r m } = - 30KJ/kg$

the negative sign because the heat is transferred from the turbine

The specific heat capacity of air is $c_p = 1.1KJ/kg \cdot K$

The inlet temperature is $T_1 = 970K$

The outlet temperature is $T_2 = 670K$

The pressure at the inlet of the turbine is $p_1 = 400 kPa$

The pressure at the exist of the turbine is $p_2 = 100kPa$

The temperature at outer surface is $T_s = 315K$

The individual gas constant of air R with a constant value $R = 0.287kJ/kg \cdot K$

The general equation for the turbine operating at steady state is \

$\r Q - \r W + \r m (h_1 - h_2) = 0$

h is the enthalpy of the turbine and it is mathematically represented as

$h = c_p T$

The above equation becomes

$\r Q - \r W + \r m c_p(T_1 - T_2) = 0$

$\frac{\r W}{\r m} = \frac{\r Q}{\r m} + c_p (T_1 -T_2)$

Where $\r Q$ is the heat transfer from the turbine

$\r W$ is the work output from the turbine

$\r m$ is the mass flow rate of air

$\frac{\r W}{\r m}$ is the rate of work developed

Substituting values

$\frac{\r W}{\r m} = (-30)+1.1(970-670)$

$\frac{\r W}{\r m}= 300kJ/kg$

The general balance equation for an entropy rate is represented mathematically as

$\frac{\r Q}{T_s} + \r m (s_1 -s_2) + \sigma = 0$

=> $\frac{\sigma}{\r m} = - \frac{\r Q}{\r m T_s} + (s_1 -s_2)$

generally $(s_1 -s_2) = \Delta s = c_p\ ln[\frac{T_2}{T_1} ] + R \ ln[\frac{v_2}{v_1} ]$

substituting for $(s_1 -s_2)$

$\frac{\sigma}{\r m} = \frac{-\r Q}{\r m} * \frac{1}{T_s} + c_p\ ln[\frac{T_2}{T_1} ] - R \ ln[\frac{p_2}{p_1} ]$

Where $\frac{\sigma}{\r m}$ is the rate of entropy produced within the turbine

substituting values

$\frac{\sigma}{\r m} = - (-30) * \frac{1}{315} + 1.1 * ln\frac{670}{970} - 0.287 * ln [\frac{100kPa}{400kPa} ]$

$\frac{\sigma}{\r m}= 0.0861kJ/kg \cdot K$

5 0

3 years ago

Explain why advances in technology can actually create more problems for engineers.

andrew11 [14]

Explanation:

Engineering is science in practical terms. It is the application of scientific findings in problem solving and creating a better world.

How does technological advancements create more problems for engineers?

Loss of job to automation: the world is driving at automating work processes through the use of specially designed and crafted machinery. Work is now properly being done using machines with little to no human input in the whole process. This is a huge let off for engineers. Engineers have to compete with machines which are their own inventions for jobs now.
Fast paced work environment: machines can handle work more efficiently and faster than the people making them. There is an increasing race between engineers and their own inventions today for better product delivery. Unless a machine is faulty, they are more productive and efficient than man. This can cause engineers to want to catch up with their own inventions leading to a work life of stress.
Environmental problems they cannot solve: most inventions use components from the environment. They release effluents that are very difficult to be properly disposed or stored. This is a huge problem for engineers and can lead to ethical calls from the government and the populace. In short, they can create problems they are expected to solve but cannot solve.
Social problems: engineers can be portrayed as terrible beings for their own inventions. This leads to psychological problems on a good and creative invention. For example, rare earth metals in DR Congo are instrumental in making solar panels, but mining of these metals have forced several thousands of people into hard and intense labor on mines; there is a call on technological firms to stop exploiting people this way for their own gains.
Misuse of technology: any good technology can be put into the wrong use. A nuclear reaction can be packaged into a bomb and also, it can be the center of electricity generation on a commercial scale. How can engineers solve this kind of problem? Technological inventions are subjective in their usage.

Learn more:

New technology brainly.com/question/5768621

#learnwithBrainly

3 0

3 years ago