How fast does a 2 inche blade have to travel to lift 1 pound?

Question

it would also help if you told me how thick the blade is, what angle its at and if there is two blades in the propeller or three

Answer 1

A two or three bladed prop of about 4"inch diam, i.e. 2" blade length runs about 15,000 rpm driven by a 0.049 engine.

It lifts a little under a pound.

Answer 2

your question makes no sense.

A blade can be inserted under a weight and used to lift it, if that is what you mean.  But it only has to travel micrometers.

edit, rereading, you mention a propeller. Do you mean a helicopter, what weight it can lift?

The more details you tell us, the better answer you get.