Gymnast with zero rotational inertia

[sciman55]

Every time a gymnast flips, charwheels and somersaults, she has rotational inertia. Now say the gymnast does not have any/zero rotational inertia, how wel would the gymnast perform and how fast would she be able to change her angular velocity (angular speed and direction)? How many times would the gymnast be able to change direction while flipping and turning?

 

P.S.: I know what moment of inertia is; I am just using rotational inertia to use as a property of moment of inertia, like linear inertia is a property of mass.

[arkain101]

they'd be able to act alot like a ghost idea..like unlimited speed.

[Qfwfq]

I am just using rotational inertia to use as a property of moment of inertia, like linear inertia is a property of mass.

If you want the right name, it's usually called angular momentum. Strictly it can also be called "moment of the quantity of motion" but that a bit long and nobody uses it, just like people say momentum for "quantity of motion". :surprise:

 

If your angular momentum is zero while in freefall, you can't change it except by having a torque applied. It is possible though to rotate your position by using complicated tricks (cats do so instinctively if you drop them upside down). It doesn't start a continued rotation, once you stop flailing arms and legs around you still won't be rotating but you might be pointing a different way.

 

edit: Of course, falling through air at high speed one can exploit the air. Freefall enthusiasts do, before opening their parachutes.