<span>Reduce energy use.
Change the way you think about transportation. Walk or bike whenever possible.
Insulate your home. Insulate yourself and your home.
Make every drop count.
</span>Cool wash and hang to dry.
<span>Switch to "green power.
</span>Recycle.
Answer:
![\Delta S=1.69J/K](https://tex.z-dn.net/?f=%5CDelta%20S%3D1.69J%2FK)
Explanation:
We know,
..............(1)
where,
η = Efficiency of the engine
T₁ = Initial Temperature
T₂ = Final Temperature
Q₁ = Heat available initially
Q₂ = Heat after reaching the temperature T₂
Given:
η =0.280
T₁ = 3.50×10² °C = 350°C = 350+273 = 623K
Q₁ = 3.78 × 10³ J
Substituting the values in the equation (1) we get
![0.28=1-\frac{Q_2}{3.78\times 10^{3}}](https://tex.z-dn.net/?f=0.28%3D1-%5Cfrac%7BQ_2%7D%7B3.78%5Ctimes%2010%5E%7B3%7D%7D)
or
![\frac{Q_2}{3.78\times 10^3}=0.72](https://tex.z-dn.net/?f=%5Cfrac%7BQ_2%7D%7B3.78%5Ctimes%2010%5E3%7D%3D0.72)
or
![Q_2=3.78\times 10^3\times0.72](https://tex.z-dn.net/?f=Q_2%3D3.78%5Ctimes%2010%5E3%5Ctimes0.72)
⇒ ![Q_2 =2.721\times 10^3 J](https://tex.z-dn.net/?f=Q_2%20%3D2.721%5Ctimes%2010%5E3%20J)
Now,
The entropy change (
) is given as:
![\Delta S=\frac{\Delta Q}{T_1}](https://tex.z-dn.net/?f=%5CDelta%20S%3D%5Cfrac%7B%5CDelta%20Q%7D%7BT_1%7D)
or
![\Delta S=\frac{Q_1-Q_2}{T_1}](https://tex.z-dn.net/?f=%5CDelta%20S%3D%5Cfrac%7BQ_1-Q_2%7D%7BT_1%7D)
substituting the values in the above equation we get
![\Delta S=\frac{3.78\times 10^{3}-2.721\times 10^3 J}{623K}](https://tex.z-dn.net/?f=%5CDelta%20S%3D%5Cfrac%7B3.78%5Ctimes%2010%5E%7B3%7D-2.721%5Ctimes%2010%5E3%20J%7D%7B623K%7D)
![\Delta S=1.69J/K](https://tex.z-dn.net/?f=%5CDelta%20S%3D1.69J%2FK)
Explanation:
Scratch the mineral with the blade of a pocket knife. Rub off any loose powder to see if the mineral has been scratched.
As they evolved and adapted, those of the fittest survived to reproduce. Those that did not adapt, died.