Based upon Max Planck's theory of black-body radiation, Einstein theorized that the energy in each quantum of light was equal to the frequency multiplied by a constant, later called Planck's constant. A photon above a threshold frequency has the required energy to eject a single electron, creating the observed effect.
Answer:

Explanation:
The pressure at the bottom of the tank is:


The force exerted on the circular bottom is:
![F=(73581.921\,Pa)\cdot (\frac{\pi}{4} )\cdot [(12\,ft)\cdot (\frac{0.305\,m}{1\,ft} )]^{2}](https://tex.z-dn.net/?f=F%3D%2873581.921%5C%2CPa%29%5Ccdot%20%28%5Cfrac%7B%5Cpi%7D%7B4%7D%20%29%5Ccdot%20%5B%2812%5C%2Cft%29%5Ccdot%20%28%5Cfrac%7B0.305%5C%2Cm%7D%7B1%5C%2Cft%7D%20%29%5D%5E%7B2%7D)

<span>
Plants and animals are multi-cellular organisms composed of eukaryotic cells, while bacteria are single-cell prokaryotic organisms. Each eukaryotic cell of a plant or animal includes a central nucleus containing DNA and membrane-bound organelles, such as endoplasmic reticulum and mitochondria. A bacterial cell has no nucleus or membrane-bound organelles.
hope it helps! :)
</span>