Question

A spherical shell of radius R is rolling down an incline of inclination q without slipping. Find minimum value of coefficient of friction –

• A. $\frac { 2 } { 7 }$ tanq
• B. $\frac { 2 } { 5 }$ tan q
• C. $\frac { 2 } { 3 }$ tan q
• D. None

Answer 1

Answer: (B)

$\frac { 2 } { 5 }$ tan q

Answer 2

F_f r = Ia ̃ mmg cos q = $\frac { 2 } { 3 }$ Ma = $\frac { 2 } { 3 }$ M $\frac { g \sin \theta } { 1 + \frac { 2 } { 3 } }$

̃ m = $\frac { 2 } { 5 }$ tan q