A tank has a gate that automatically opens if the water levelhis high enough. The gate has a squarecross section of side1m and can rotate about an axis going through the point O. Calculate the minimumwater level that would trigger the opening of the floodgate.

The gate will open if the height of water is equal to or more than 0.337m.

Explanation:

From the diagram attached, (as seen from the reference question found on google)

The forces are given as

Force on OA

Here

The  Force is given as

Force on OB

Here

The  Force is given as

Now the moment arms are given as

Taking moment about the point O as zero

So the gate will open if the height of water is equal to or more than 0.337m.

there are no correct statementd on the list of choices you provided.

dang that balls went far