Two hollow cylinderical drums one of radius R and other 2R but of a common height 'h' are rotating with angular velocity `omega` in anticlockwise direction and also `omega` in clockwise direction respectively, with their axes fixed and parallel to each other in a horizontal plane saparated by little greater than 3R distance so that they just do not touch each other. They are now brought in contact making the separation exactly 3R. What would be the ratio of final angular velocity of the two when friction ceases ?

Options

A. `(2)/(1)`
B. `(3)/(1)`
C. `1//2`
D. `1//3`

Answer

A

Explanation

In balancing position F. = F = F.. or net force `F_("net")=0`

Here let `omega_(1)andomega_(2)` be the final angular velocity in anticlockwise and clockwise directions respectively. Finally as the friction ceases, then
`Romega_(1)=2Romega_(2)`
or `(omega_(1))/(omega_(2))=(2)/(1)`