Mechanical Energy: Solving for Speed of Ball at Lowest Point

[norcal]

Homework Statement

A thin rod, of length L and negligible mass, that can pivot about one end to rotate in a vertical circle. A heavy ball of mass m is attached to the other end. The rod is pulled aside through an angle and released.
What is the speed of the ball at the lowest point if L = 2.20 m, = 19.0°, and m = 500 kg?

Homework Equations

W=mgd(cos theta)
KE=(1/2)mv^2

The Attempt at a Solution

How do I get the velocity? Can I get it by using the above equations if I solve for W? Where do I plug the answer for W into find the velocity?

 

[Mentz114]

Do you know what W is as defined in your post ? Can you give it a name ?

 

[norcal]

W=work done