Acceloration and tension of a pendulum

[BoldKnight399]

A bowling ball weighing 72.0N is attached to the ceiling by a rope of length 3.78 m. the ball is pulled to one side and released; it then swings back and forth as a pendulum. As the rope swings through the vertical, the speed of the bowling abll is 4.00 m/s. What is the acceleration of the bowling ball, in magnitude and direction, at this instant?

So I was thinking that the direction would be negative and the direction would be perpendicular to the tension and the weight of the rope.
The problem is that I do not know how to get that.
Should it be that a=v^2/R like circular motion?

I also need to find the tension in the rope at this instant. I thought it would just be the opposite of the weight because the ball is not rising above itself and the tension is remaining constant. But that wasn't the right answer, so I will admit that I am totally lost and confused as to how to approach this problem now.

 

[tiny-tim]

Hi BoldKnight399!

(try using the X² icon just above the Reply box )

This is just another F = ma problem.

Take it step by step …

first find the acceleration, a (that's just geometry),

then (since you know the weight) use F = ma to find T.

(btw, "like circular motion"? this is circular motion! )