How many liters of water at 20 °C and 90
°C need to be mixed
to obtain 300 liters of
water at 30 °C?

The energy resource brought into a coal power plant is coal.

Found the answer at: https://www.tva.com/energy/our-power-system/coal/how-a-coal-plant-works#:~:text=Coal%2Dfired%20plants%20produce%20electricity,to%20start%20the%20process%20over.

The waste produced by coal power plants is coal ash and the energy produced by coal power plants is electricity.

Answers found at: http://www.groundtruthtrekking.org/Issues/AlaskaCoal/Coal-Ash-Combustion-Wastes.html       and        https://www.tva.com/energy/our-power-system/coal/how-a-coal-plant-works#:~:text=Coal%2Dfired%20plants%20produce%20electricity,to%20start%20the%20process%20over.

The two laws of thermodynamics apply to what I found out in my research because I know that the entropy increase due to the combustion of conventional fuels is much larger than that resulting from that of nuclear fuels, and is therefore much more dangerous. Also, I know that heat is used to burn coal and create energy.

Found answer at: https://www.encyclopedie-energie.org/en/energy-consumption-and-entropy-release-in-the-biosphere/

Explanation:

Hope this helps, i got an okay score on it but better than nothing i guess lol