What is the radial acceleration of a pendulum at a given angle?

[jg727]

A pendulum (with string length "L") and aball of mass "m" is pulled back to a horizontal position and then released. Assuming that θ is the angle between the string and the vertical, find (a.) the magnitude of the radial acceleration of this ball at an angle of θ as a function of m,g, L, and/or θ.


I think I found what "V" is but I am not completely sure.

 

[cepheid]

You know from the equation for centripetal acceleration that a is going to depend on v and the radius, which is L in this case. However, v is not constant, but rather is a function of theta. You need to find this function.