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3 years ago

11

The resistance of a copper wire 200 m long is 21 Q. If its thickness (diameter) is 0.44 mm, its specific resistance is around___

____________?

1 answer:

fenix001 [56]3 years ago

7 0

Answer:

Its specific resistance will be around 0.015

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Your new team is working hard, but they are all less experienced than you and don't complete their tasks as quickly.What would y

irina1246 [14]

I believe most likely: (C) least likely: (B)

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3 years ago

Engineering is a broad category that includes a variety of occupations and attempts to solve problems using math and

nadezda [96]

Answer:

Engineering is a broad category that includes a variety of occupations and attempts to solve problems using math and systematic and scientific processes.

Explanation:

Engineering is the scientific discipline that deals with the implementation of science on materials, constructions, machines, systems and processes to realize a specific goal. It is an area of technical activity that includes a number of specialized areas and disciplines aimed at the practical application of scientific, economic, social and practical knowledge in order to turn natural resources for the benefit of humans.

The goals of engineering activities are the invention, development, creation, implementation, repair, maintenance and / or improvement of equipment, materials or processes. Engineering is closely intertwined with science, relying on the postulates of fundamental science and the results of applied research. In this sense, it is a branch of scientific and technical activity.

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3 years ago

Liquid water is fed to a boiler at 24°C and 10 bar is converted at a constant pressure to saturated steam.

zepelin [54]

We can find the change in the enthalpy through the tables A5 for Saturated water, pressure table.

For 1bar=1000kPa:

$T_{sat}=179.88\°c$

$H_{fg} = 2014.6kJ/kg$

$c_p=4.18 kJkg^{-1}{K^{-1}$

$\nu_g = 0.19436m^3/kg$

Replacing,

$\Delta h = h_{fg}+c_p(T_{sat}-T_{inlet})$

$\Delta h = 2014.6+4.18(179.88-24)$

$\Delta h=2666.17kJ/kg$

With the specific volume we know can calculate the mass flow, that is

$\dot{m}=\frac{\frac{15000}{3600}}{0.19436}$

$\dot{m} = 21.4378kg/s$

Then the heat required in input is,

$Q=\dot{m}\Delta h$

$Q=21.4378*2666.17$

$Q=57157.036kW$

With the same value required of 15000m^3/h, we can calculate the velocity of the water, that is given by,

$V= \frac{\dotV}{A}$

$V = \frac{\frac{15000}{3600}}{\pi /4 *(0.15)^2}$

$V=235.79m/s$

Finally we can apply the steady flow energy equation, that is

$\dot{m}(h_1+\frac{V^2}{2000})+Q = \dot{m}h_2$

Re-arrange for Q,

$Q=\dot{m}(h_2-h_1-\frac{V^2}{2000})$

$Q=\dot{m}(\Delta h-\frac{V^2}{2000})$

$Q= (21.4378)(2666.17-\frac{235.79^2}{2000})$

$Q= 56560.88kW$

We can note that consider the Kinetic Energy will decrease the heat input.

4 0

3 years ago

A plant has ten machines and currently operates two 8-hr shift per day, 5 days per week, 50 weeks per year. the ten machines pro

Zarrin [17]

Answer:

83.6%

Explanation:

<h3>(a)</h3>

On its current schedule, the plant can theoretically produce ...

(30 pc/h/machine)(10 machine)(8 h/shift)(2 shift/day)(5 day/wk)(50 wk/yr)

= (30)(10)(8)(2)(5)(50) pc/yr = 1,200,000 pc/yr

__

<h3>(b)</h3>

On the proposed schedule, this production becomes ...

(30 pc/mach)(10 mach)(8 h/sh)(3 sh/da)(6 da/wk)(51 wk/yr)

= (30)(10)(8)(3)(6)(51) pc/yr = 2,203,200 pc/yr

The increase in capacity is ...

(2,203,200/1,200,000 -1) × 100% = 83.6% . . . capacity increase

_____

<em>Additional comment</em>

The number of parts per shift did not change. Only the number of shifts per year changed. It went up by a factor of (3/2)(6/5)(51/50) = 1.836. Hence the 83.6% increase in capacity.

We have to assume that maintenance and repair are done as effectvely as before in the reduced down time that each machine has.

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2 years ago

All circuits need three basic parts: an energy source, wires, and the object that is going to change the electrical energy into

Radda [10]

load every electric circuit,regardless of where it is or how large or small, has four basic parts: an energy source (ac or dc),a conductor (wire), an electrical load (device), and at least one controller(switch)

7 0

4 years ago

Read 2 more answers