A particle traveling horizontally with speed u collides and sticks with a particle of equal mass hanging at rest at the end of a light inextensible string of length 21. If the string rotates through an angle of 60° before its velocity becomes zero, then u is

A particle traveling horizontally with speed u collides and sticks wit

1.	A particle traveling horizontally with speed u collides and sticks with a particle of equal mass hanging at rest at the end of a light inextensible string of length 21. If the string rotates through an angle of 60° before its velocity becomes zero, then u is
Answer» `SQRT(4GL)` `sqrt(8gl)` `sqrt(2gl)` `sqrt(GL)` ANSWER :B