Answer:
Temperature at the bottom will be 19.18°C
Explanation:
We have given height h = 807 m
Temperature at the top 
Specific heat of water c = 4200 
From energy conservation
Kinetic energy at the bottom = potential energy at the top
So 

So temperature at the bottom = 17.3+1.88 = 19.18°C
Explanation:
At first sight, it doesn’t make sense that both fission and fusion release energy.
The key is in how tightly the nucleons are held together in a nucleus. If a nuclear reaction produces nuclei that are more tightly bound than the originals, then the excess energy will be released.
It turns out that the most tightly bound atomic nuclei are around the size of iron-56.
Thus, if you split a nucleus that is much larger than iron into smaller fragments, you will release energy because the smaller fragments are at a lower energy than the original nucleus.
If instead you fuse very light nuclei to get bigger products, energy is again released because the nucleons in the products are more tightly bound than in the original nuclei.
https://socratic.org/questions/how-are-fusion-and-fission-similar
Temperature can change the state from solid to liquid causing it to melting, liquid to gas causing vaporization or a solid to a gas causing sublimation. Pressure alone cannot change the state of matter.
Yes, for balance.hope this helped.