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3 years ago

Please help on this one?

Physics

1 answer:

scoray [572]3 years ago

8 0

option B open system

because in open system energy and mass can escape from the system or can be added to it.

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A skydiver falls toward the ground at a constant velocity. Which statement best applies Newton’s laws of motion to explain the s

Tema [17]

Answer:

The answer is (a.) An upward force balances the downward force gravity on the skydiver

The skydiver is falling at a constant velocity because the upward force is balancing the downward force of gravity. According to Newton, the opposite force balance each other. This is stated in Newton's second law of motion.

7 0

3 years ago

Read 2 more answers

Discuss Joule-Thompson effect with relevant examples and formulae.

Delicious77 [7]

Answer:

$\mu _j=\dfrac{1}{C_p}\left [T\left(\frac{\partial v}{\partial T}\right)_p-v\right]dp$

Explanation:

Joule -Thompson effect

Throttling phenomenon is called Joule -Thompson effect.We know that throttling is a process in which pressure energy will convert in to thermal energy.

Generally in throttling exit pressure is low as compare to inlet pressure but exit temperature maybe more or less or maybe remains constant depending upon flow or fluid flow through passes.

Now lets take Steady flow process

Let

$P_1,T_1$ Pressure and temperature at inlet and

$P_2,T_2$ Pressure and temperature at exit

We know that Joule -Thompson coefficient given as

$\mu _j=\left(\frac{\partial T}{\partial p}\right)_h$

Now from T-ds equation

dh=Tds=vdp

$Tds=C_pdt-\left [T\left(\frac{\partial v}{\partial T}\right)_p\right]dp$

⇒ $dh=C_pdt-\left [T\left(\frac{\partial v}{\partial T}\right)_p-v\right]dp$

So Joule -Thompson coefficient

$\mu _j=\dfrac{1}{C_p}\left [T\left(\frac{\partial v}{\partial T}\right)_p-v\right]dp$

This is Joule -Thompson coefficient for all gas (real or ideal gas)

We know that for Ideal gas Pv=mRT

$\dfrac{\partial v}{\partial T}=\dfrac{v}{T}$

So by putting the values in

$\mu _j=\dfrac{1}{C_p}\left [T\left(\frac{\partial v}{\partial T}\right)_p-v\right]dp$

$\mu _j=0$ For ideal gas.

6 0

3 years ago

Heat is conducted in the axial direction through a cylinder by heating one end. If the diameter of the cylinder is doubled (but

CaHeK987 [17]

Answer:

hello your question is incomplete attached below is the complete question with the options

answer : Doubling the Diameter increases the heat transfer rate by a factor of 4 ( B )

Explanation:

The heat transfer in the axial direction of the cylinder can be calculated/determined as attached below

$\frac{q_{2} }{q_{1} } = \frac{(2D)^2}{D^2}$

$q_{2}$ = 4 $q_{1}$ ( This shows that Doubling the diameter increases the heat transfer rate by a factor of 4 )

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3 years ago

How do you think scientists figure out what they think the population will be in 2050?

laila [671]

They would most likely use statistics on the increase/decrease in population from previous decades and centuries. In addition to these statistics, they could use the birth and death rate and ultimately predict the increase within these next 30 years. They must also take climate change and other environmental factors into consideration when formulating such a bold prediction.

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4 years ago

A magnetic field is formed when electric charges move. When the electric charges stop moving, the magnetic field (which was form

Natali5045456 [20]

True

Explanation:

when electrons stop.moving it cause a stoppage

in formation of magnetic field

i hope.it helps u

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3 years ago