Hi there!
The answer would be B. the slope of the plane.
Changing the slope of the plane would show how fast the ball went when Galileo changed the steepness of the slope. If he didn’t change the slopes steepness he would have the same results each time.
Hope this helps !
The equivalent of the Newton's second law for rotational motions is:
![\tau = I \alpha](https://tex.z-dn.net/?f=%5Ctau%20%3D%20I%20%5Calpha)
where
![\tau](https://tex.z-dn.net/?f=%5Ctau)
is the net torque acting on the object
![I](https://tex.z-dn.net/?f=I)
is its moment of inertia
![\alpha](https://tex.z-dn.net/?f=%5Calpha)
is the angular acceleration of the object.
Re-arranging the formula, we get
![I= \frac{\tau}{\alpha}](https://tex.z-dn.net/?f=I%3D%20%5Cfrac%7B%5Ctau%7D%7B%5Calpha%7D%20)
and since we know the net torque acting on the (vase+potter's wheel) system,
![\tau=16.0 Nm](https://tex.z-dn.net/?f=%5Ctau%3D16.0%20Nm)
, and its angular acceleration,
![\alpha = 5.69 rad/s^2](https://tex.z-dn.net/?f=%5Calpha%20%3D%205.69%20rad%2Fs%5E2)
, we can calculate the moment of inertia of the system: