# Homework Help: Direction of acceleration in pendulum bob?

1. Sep 23, 2011

### SUROJL

A simple pendulum consists of a mass M tied to a string and swings freely
starting from rest at the position on the left in the figure below.

http://imageshack.us/photo/my-images/695/screenshot20110922at611.png/

Select the vectors which best represent the acceleration of mass M at the five
positions labeled 1,2,3,4,5 as the mass
swings from left to right. (If for position 1 the
acceleration is A, and for positons 2,3,4,5 it
is B, enter ABBBB.

Attempts
The mg component which is downward is split-ted into vertical and horizontal component. Tension is balanced by mgcos(theta) and mgsin(theta) produces acceleration in the bob of pendulum
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Sep 23, 2011

### TomFoolery

the acceleration "should" always point toward the center. This is due to the tension in the wire.

*still, I'd wait for another reply to confirm this.