Look up the atmospheric (or barometric) pressure in your area in the newspaper, on television, or through another news outlet. What are the units used? Convert to mm Hg. Convert to mm H2O.

Sure sounds like you haven't been paying attention in class. We have a policy about not doing homework.

AT least you should be able to do: "Look up the atmospheric (or barometric) pressure in your area in the newspaper, on television, or through another news outlet. What are the units used?"

And I know you can convert from units used to mm Hg.

The last one is a bit harder.

Hint: The water column has to be much much bigger than Hg. Why?