1974M2. The moment of inertia of a uniform solid sphere (mass M , radius R ) about a diameter is 2MR2/5. The sphere is placed on an inclined plane (angle θ ) as shown above and released from rest.
a. Determine the minimum coefficient of friction μ between the sphere and plane with which the sphere will roll down the incline without slipping
b. If μ were zero, would the speed of the sphere at the bottom be greater, smaller, or the same as in part a.? Explain your answer.