A hollow spherical ball is given an initial push, up an incline of inclination angle `alpha`. The ball rolls purely coefficient of static friction between ball and incline `=mu`. During its upwards journey.

Options

A. friction acts up along the incline
B. `mu_(min)=(2tanalpha)//5`
C. friction will be no rotation if `h=R`
D. `mu_(min)=(2tanalpha)//7`

Explanation

To solve the problem of a hollow spherical ball rolling up an incline, we need to analyze the forces acting on the ball and determine the direction of friction, as well as the minimum coefficient of static friction required for pure rolling.

### Step-by-Step Solution:

1. **Identify Forces Acting on the Ball:**
- The gravitational force acting downward: \( mg \).
- The component of gravitational force acting parallel to the incline: \( mg \sin \alpha \).
- The component of gravitational force acting perpendicular to the incline: \( mg \cos \alpha \).
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