I have this od chestnut to solve, I have done as much as what I think is right but I need some assistance:

a) A body of mass m kg is attached to a point by string of length

1.25 m. If the mass is rotating in ahorizontalcircle0.75 m below the

point of attachment, calculate its angular velocity.

So far I have:

Have I totally done this wrong, also were do I need to go from here?

Thanks