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4 years ago

3. Can there be forces acting on an object at rest? Explain why or why not.

1 answer:

3 0

Yes, because gravity always exerts a force whether an object is at rest or in motion. Gravity is the reason we aren’t all floating as cool as that would be we would probably be hit by a plane

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Why should you do you should

uranmaximum [27]

One does not simply should you do you should

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3 years ago

AIR MASSES!!

777dan777 [17]

Answer:

A : hot and moist, maritime tropical

B: cold and dry, maritime polar

C: hot and moist , maritime tropical

D: cold and dry, continental polar

E: hot and moist , maritime tropical

F: cold and dry , maritime polar

Explanation:

Cold air is denser than warm air. The more water vapor that is in the air, the less dense the air becomes. That is why cold, dry air is much heavier than warm, humid air.

Maritime polar (mP) air masses are cool, moist, and unstable. Some maritime polar air masses originate as continental polar air masses over Asia and move westward over the Pacific, collecting warmth and moisture from the ocean.

Maritime tropical (mT) air masses are warm, moist, and usually unstable.

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4 years ago

A counterflow double-pipe heat exchanger is used to heat water from 20°C to 80°C at a rate of 1.2 kg/s. The heating is to be com

bixtya [17]

Answer:L=109.16 m

Explanation:

Given

initial temperature $=20^{\circ}C$

Final Temperature $=80^{\circ}C$

mass flow rate of cold fluid $\dot{m_c}=1.2 kg/s$

Initial Geothermal water temperature $T_h_i=160^{\circ}C$

Let final Temperature be T

mass flow rate of geothermal water $\dot{m_h}=2 kg/s$

diameter of inner wall $d_i=1.5 cm$

$U_{overall}=640 W/m^2K$

specific heat of water $c=4.18 kJ/kg-K$

balancing energy

Heat lost by hot fluid=heat gained by cold Fluid

$\dot{m_c}c(T_h_i-T_h_e)= \dot{m_h}c(80-20)$

$2\times (160-T)=1.2\times (80-20)$

$160-T=36$

$T=124^{\circ}C$

As heat exchanger is counter flow therefore

$\Delta T_1=160-80=80^{\circ}C$

$\Delta T_2=124-20=104^{\circ}C$

$LMTD=\frac{\Delta T_1-\Delta T_2}{\ln (\frac{\Delta T_1}{\Delta T_2})}$

$LMTD=\frac{80-104}{\ln \frac{80}{104}}$

$LMTD=91.49^{\circ}C$

heat lost or gain by Fluid is equal to heat transfer in the heat exchanger

$\dot{m_c}c(80-20)=U\cdot A\cdot$ (LMTD)

$A=\frac{1.2\times 4.184\times 1000\times 60}{640\times 91.49}=5.144 m^2$

$A=\pi DL=5.144$

$L=\frac{5.144}{\pi \times 0.015}$

$L=109.16 m$

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3 years ago

Spiders kan swim???????

Nastasia [14]

Answer:

Spiders cannot actually propel their bodies through the water as a swimmer does, but they can use objects to get across the water and some can run across the water.

Explanation:

3 0

3 years ago

Read 2 more answers

Summarize renewable energy saves water and creates jobs

siniylev [52]

Answer: Solar Energy has been helping the supplying companies to be able to hire more people for jobs which helps 12 times more easier than the US, Things like solar, geothermal, and wind can help reduce the water resources which helps to save our water conservation rate which was getting increasingly High.

<em>I hope this explanation had helped you today!</em>

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3 years ago