All categories

3 years ago

Suppose you have 1 kg each of iron, glass, and water, and all three samples are at 10°C.

Physics

1 answer:

Kipish [7]3 years ago

6 0

To solve this problem it is necessary to apply the concepts related to heat exchange and Entropy.

The temperature and mass remain constant, therefore the entropy values will be the only ones to change.

Of the three elements given their entropy values are given by

$\Delta S_{iron}=0.45J/gmC$

$\Delta S_{glass}=0.8J/gmC$

$\Delta S_{water}= 4.186J/gmC$

Part A) From thermodynamic theory we know that temperature is inversely proportional to entropy

$T = \frac{E}{\Delta S} \rightarrow$ Energy remains constant

$\Delta t \propto \frac{1}{S}$

Therefore the order would be

Lowest Temperature= Water

Medium Temperature= Glass

Highest Temperature=Iron

Part B) In the case of Energy the opposite happens because it is proportional to the entropy, then

$E = T(\Delta S) \rightarrow$ Temperature is constant

$E \propto S$

Lowest Energy = Iron

Medium Energy = Glass

Highest Energy = Water

You might be interested in

Zoey ran a total of 1000m. 20 seconds into her run she had traveled 100 meters. What was her speed at 100 meters?

leva [86]

Let's assume that Zoey ran at a constant speed. we can use the equation,
d = st
where, d = distance, s = speed, and t = time taken.

By rearranging,
s = d/t
Zoey had travelled 100 m in 20 seconds.
Hence, s = 100 m / 20 s = 5 m/s

therefore Zoey's speed at 100 m is 5 m/s

7 0

3 years ago

A sailboat runs before the wind with a constant speed of 2.8 m/s in a direction 52° north of west. How far (a) west and (b) nort

vodka [1.7K]

<h2>Displacement along west = 3612 m</h2><h2>Displacement along north = 4633.50 m</h2>

Explanation:

Let east be positive x axis and north be positive y axis

Velocity of boat = 2.8 m/s in a direction 52° north of west.

Velocity, v = -2.8 cos 52 i + 2.8 sin 52 j = -1.72 i + 2.21 j m/s

Time taken = 35 min = 35 x 60 = 2100 s

Displacement = Velocity x Time

Displacement = (-1.72 i + 2.21 j) x 2100

Displacement = -3612 i + 4633.50 j m

Displacement along west = 3612 m

Displacement along north = 4633.50 m

6 0

3 years ago

One end of a string is fixed. An object attached to the other end moves on a horizontal plane with uniform circular motion of ra

sveticcg [70]

Answer:

If both the radius and frequency are doubled, then the tension is increased 8 times.

Explanation:

The radial acceleration ( $a_{r}$ ), measured in meters per square second, experimented by the moving end of the string is determined by the following kinematic formula:

$a_{r} = 4\pi^{2}\cdot f^{2}\cdot R$ (1)

Where:

$f$ - Frequency, measured in hertz.

$R$ - Radius of rotation, measured in meters.

From Second Newton's Law, the centripetal acceleration is due to the existence of tension ( $T$ ), measured in newtons, through the string, then we derive the following model:

$\Sigma F = T = m\cdot a_{r}$ (2)

Where $m$ is the mass of the object, measured in kilograms.

By applying (1) in (2), we have the following formula:

$T = 4\pi^{2}\cdot m\cdot f^{2}\cdot R$ (3)

From where we conclude that tension is directly proportional to the radius and the square of frequency. Then, if radius and frequency are doubled, then the ratio between tensions is:

$\frac{T_{2}}{T_{1}} = \left(\frac{f_{2}}{f_{1}} \right)^{2}\cdot \left(\frac{R_{2}}{R_{1}} \right)$ (4)