Posted by rosa on .
A yo-yo of mass m rests on the floor (the static friction coefficient with the floor is mu ). The inner (shaded) portion of the yo-yo has a radius R-1 , the two outer disks have radii R-2 . A string is wrapped around the inner part. Someone pulls on the string at an angle Beta (see sketch). The "pull" is very gentle, and is carefully increased until the yo-yo starts to roll without slipping.
For what angles of beta will the yo-yo roll to the left and for what angles to the right?
a) Yo-Yo rolls to the left if sin beta<R-1/R_2 , and to the right if sin beta> R_1/R_2.
b)Yo-Yo rolls to the left if sin beta>R-1/R_2 , and to the right if sin beta<R_1/R_2
c)yo- yo rolls to the left if cos beta< R_1/R_2 and to the right if cos beta>R_1/R-2
d)yo yo rolls to the left if cosbeta>R_1/R_2 and to the right if cosbeta< R_1/R_2 .