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1 year ago

5

The air within a piston equipped with a cylinder absorbs 565 J of heat and expands from an initial volume of 0.10 L to a final v

olume of 0.85 L against an external pressure of 1.0 atm. What is the change in internal energy of the air within the piston

1 answer:

jeyben [28]1 year ago

5 0

Answer:

489 J

Explanation:

According to the first law of thermodynamics:-

$\Delta U = q + w$

Where,

U is the internal energy

q is the heat

w is the work done

From the question,

q = + 565 J (+ sign as the heat is being absorbed)

The expression for the calculation of work done is shown below as:

$w=-P\times \Delta V$

Where, P is the pressure

$\Delta V$ is the change in volume

From the question,

$\Delta V$ = 0.85 - 0.10 L = 0.75 L

P = 1.0 atm

$w=-1.0\times0.75\ atmL$

Also, 1 atmL = 101.3 J

So,

$w=-1.0\times0.75\times 101.3\ J=-76\ J$ (work is done by the system)

So,

$\Delta U = +565\ J-76\ J = 489\ J$

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2 years ago

The temperature, T, of a gas is jointly proportional to the pressure P of the gas and the volume V occupied by the gas. Use C as

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Answer:

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Explanation:

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The second case is the case of the direct proportionality: It is said that x and y are directly proportional if

$\frac{x}{y} =C$ : x is directly proportional to y.

or

$\frac{y}{x} =C$ : y is directly proportional to x.

Always that any text does not specify about directly or inversely proportionality, it is assumed to mean directly automatically.

For our case, we are said that the temperature T is proportional to the pressure P and the volume V (we assume that it means directly); it is a double proportionality but follows the same rules:

If T were just proportional to P, we would have:

$\frac{T}{P} =C$

If T were just proportional to V, we would have:

$\frac{T}{V} =C$

As T is proportional to both P and V, the right equation is:

$\frac{T}{P*V}=C$

In order to isolate the temperature, let's multiply (P*V) at each side of the equation:

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Substituting (2) into (1) to give the angle;

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Answer:

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