Rolling Objects by Walter Lewin 

for a rolling object, with mass m, descending a ramp with inclination teta, the linear acceleration is given by the following expression: a = (m*g*sin(teta)) / (m+(I/r^2)) where I denotes the rotational inertia or mass moment of inertia at the center of mass, and r is the radius below are the mass moment of inertia for several rolling objects: 1. Solid Sphere: 2/5 *m*r^2 2. Hollow Sphere: 2/3 *m*r^2 3. Solid Cylinder: 1/2 *m*r^2 4. Hollow Cylinder: m*r^2 thus, corresponding accelerations are: 1. Solid Sphere: a = 5/7*g*sin(teta) 2. Hollow Sphere: a = 3/5*g*sin(teta) 3. Solid Cylinder: a = 2/3*g*sin(teta) 4. Hollow Cylinder: a = 1/2*g*sin(teta) hence, in a race between these 4 rolling objects down in an inclined plane the results are: 1st place: Solid Sphere 2nd place: Solid Cylinder 3rd place: Hollow Sphere 4th place: Hollow Cylinder See demonstrative video of this race in the following link (instant of time 55min 05sec): ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-eXfwodnO6lc.html

Great lesson from Dr. Lewin. Great mentor and physician. Big Thanks.

this is a very important experiment, and it tells the diameter does not affect the acceleration of the cylinder rolling down on the slope.

a= (2/3)g •sin( alfa) ,cilinder