Final answer:
The furthest below the top-most surface of the main hoop that supports can be placed is the bottom, as it supports the weight of the fluid in a container.
Step-by-step explanation:
In physics, the furthest below the top-most surface of the main hoop that supports can be placed is the bottom. In a container holding fluid, such as a water tank, the bottom surface supports the entire weight of the fluid. The vertical sides of the container cannot exert an upward force on the fluid, so the bottom must support it all. This is because the vertical sides cannot withstand a shearing force.