Pendulum String Breaking Point Problem

[aboothby]

A 2.05 kg ball is attached to the bottom end of a length of fishline with a breaking strength of 10 lb (44.5 N). The top end of the fishing line is held stationary. The ball is released from rest with the line taut and horizontal ( = 90.0°). At what angle (measured from the vertical) will the fishline break?

How do you figure this out without knowing the length of the pendulum string?

 

[andrevdh]

Consider the force components along the line of the string.

Then also use energy conservation.