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3 years ago

A welding machine that is called a drooper is a ____ machine

Engineering

1 answer:

love history [14]3 years ago

6 0

Answer:

constant current

Explanation:

The curve of a constant current machine droops downward rather sharply and for this reason, this type of machine is called a "drooper."

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The driveshaft of an automobile is being designed to transmit 238 hp at 3710 rpm. Determine the minimum diameter d required for

AURORKA [14]

Explanation:

Below is an attachment containing the solution.

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4 years ago

It is possible to maintain a pressure of 10 kPa in a condenser that is being cooled by river water entering at 20 °C?

vovangra [49]

Answer:

Yes, it is possible to maintain a pressure of 10 kPa in a condenser that is being cooled by river water that is entering at 20 °C because this temperature (20 °C) of the external cooling water is less than the saturation temperature of steam which is which is 45.81 °C, and heated by a boiler; as a result of this condition, coupled with the assumption that the turbine, pump, and interconnecting tube are adiabatic, and the condenser exchanges its heat with the external cooling river water, it possible to maintain a pressure of 10 kPa.

5 0

4 years ago

1. (5 pts) An adiabatic steam turbine operating reversibly in a powerplant receives 5 kg/s steam at 3000 kPa, 500 °C. Twenty per

KiRa [710]

Answer:

temperature of first extraction 330.8°C

temperature of second extraction 140.8°C

power output=3168Kw

Explanation:

Hello!

To solve this problem we must use the following steps.

1. We will call 1 the water vapor inlet, 2 the first extraction at 100kPa and 3 the second extraction at 200kPa

2. We use the continuity equation that states that the mass flow that enters must equal the two mass flows that leave

m1=m2+m3

As the problem says, 20% of the flow represents the first extraction for which 5 * 20% = 1kg / s

solving

5=1+m3

m3=4kg/s

we find the enthalpies and temeperatures in each of the states, using thermodynamic tables

Through laboratory tests, thermodynamic tables were developed, these allow to know all the thermodynamic properties of a substance (entropy, enthalpy, pressure, specific volume, internal energy etc ..)

through prior knowledge of two other properties

4.we find the enthalpy and entropy of state 1 using pressure and temperature

h1=Enthalpy(Water;T=T1;P=P1)

h1=3457KJ/kg

s1=Entropy(Water;T=T1;P=P1)

s1=7.234KJ/kg

remembering that it is a reversible process we find the enthalpy and the temperature in the first extraction with the pressure 1000 kPa and the entropy of state 1

h2=Enthalpy(Water;s=s1;P=P2)

h2=3116KJ/kg

T2=Temperature(Water;P=P2;s=s1)

T2=330.8°C

5.we find the enthalpy and the temperature in the second extraction with the pressure 200 kPav y the entropy of state 1

h3=Enthalpy(Water;s=s1;P=P3)

h3=2750KJ/kg

T3=Temperature(Water;P=P3;s=s1)

T3=140.8°C

Finally, to find the power of the turbine, we must use the first law of thermodynamics that states that the energy that enters is the same that must come out.

For this case, the turbine uses a mass flow of 5kg / s until the first extraction, and then uses a mass flow of 4kg / s for the second extraction, taking into account the above we infer the following equation

W=m1(h1-h2)+m3(h2-h3)

W=5(3457-3116)+4(3116-2750)=3168Kw

7 0

3 years ago

Give me a smart goals to achieve

S_A_V [24]

Just a suggestion: i would start with short-term goals to help you build up to your long-term goals

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3 years ago

Read 2 more answers

The atmosphere is divided into different layers, each with a different function. The stratosphere contains the ozone (O3).

tangare [24]

Answer:

a) At about 15 to 35 km from the Earth

b) It helps to absorb most of the ultraviolet rays from the sun, that is otherwise too dangerous here on Earth.

c) The depletion of the ozone layer is due to free radical catalysts, like nitric oxide (NO), nitrous oxide (N2O), hydroxyl (OH), but majorly due to atomic chlorine (Cl), and atomic bromine (Br) finding their way up to the the ozone layer.

d) The refrigeration processes and the aerosol aligned industrial processes, are the major culprits.

Explanation:

a) The ozone layer is lies in the lower portion of the stratosphere, from an height of about 15 to 35 kilometers from the surface of the Earth.

b) The ozone layer contains a large portion of ozone, a molecule of oxygen containing three oxygen atom bonded together. This ozone is created at this level by the action of ultraviolet radiation on an ordinary oxygen molecule, splitting it into two oxygen atom. Each of this oxygen atom then proceed to combine with another ordinary oxygen molecule, to form an ozone molecule. The ozone at this layer absorbs a large portion of the ultraviolet radiation from the sun.

c) The depletion of the ozone layer is due to the presence of some radical, that are able to survive up to the level of the ozone layer. At this level, ultraviolet radiation causes these these radicals to dissociate to give free bromine and chlorine mostly. This chlorine and bromine molecules breaks down the ozone molecules.

d) The various industrial processes includes refrigeration, and the aerosol industries that majorly releases the chlorofluorocarbons (CFCs) and bromofluorocarbons, which are the main culprits of ozone depletion.

5 0

3 years ago