Answer:
v = 4.98 m/s
Explanation:
As the massive ball is attached to the end of the rod
Now the ball will move in vertical circle such that it will just complete the vertical circle
So at the top position of its motion the velocity of ball must be zero
now we can use mechanical energy conservation as we know that there is no friction force here
[tex]\frac{1}{2}mv^2 = mgh[/tex]
[tex]\frac{1}{2}mv^2 = mg(2L)[/tex]
[tex]\frac{1}{2}m(v^2) = m(9.81)(2\times 0.633)[/tex]
[tex]v^2 = 2(9.81)(2\times 0.633)[/tex]
[tex]v = 4.98 m/s[/tex]