Question

A ball of radius r lies at the bottom of a vertical ring of radius R, find the minimum velocity to be given so that the ball completes the loop rolling without slipping.

• A. $\sqrt { 5 g ( R - r ) }$
• B. $\sqrt { \frac { 27 } { 10 } g ( R - r ) }$
• C. $\sqrt { \frac { 27 } { 7 } g ( R - r ) }$
• D. $\sqrt { \frac { 27 } { 5 } g ( R - r ) }$

Answer 1

Answer: (C)

$\sqrt { \frac { 27 } { 7 } g ( R - r ) }$

Answer 2

8 × 6 sin30 = F × 16 or F = 1.5N