What size propeller for a 36 V DC motor?

"Morgans" jsmorgan charterJUNK.net wrote:

....

I seriously doubt that you are going to get more than 8 pounds
of thrust out of that motor, even with the ideal gearbox and
prop. Probably not going to do well to move a person on skates.

Right... Just depends on how easy it is to try. But maybe I can
get a feel for what sort of electric motor would do. Propeller
powered inline skating has been done with small gasoline/petrol
motors.

http://www.youtube.com/results?searc...e+jetpack&aq=f

The first clip is on topic after the cool hang gliding introduction.

But I would not want to use a noisy gasoline motor.

Thanks.