# Homework Help: How to figure out when a table will tip over

1. Oct 4, 2011

### ssnapier

1. The problem statement, all variables and given/known data

How Close to the edge of a 20kg table, can a 66kg person sit without tipping it over?
The table is 2.2m long and there are two legs placed 0.5 m from each end of the table with 1.2 meters between the two legs and the top of the table is 0.80 m tall

2. Relevant equations

I am totally at a loss here, do I use r/R=Fd/gravity?

3. The attempt at a solution

2. Oct 4, 2011

### davo789

The question you need to ask is why does the table tip up at all?

3. Oct 4, 2011

### ssnapier

It tips because the guy sits on the edge and disturbs the balance (changes the center of gravity). I still have no idea how what equation I should be using.

4. Oct 4, 2011

### davo789

The table is symmetric, and you can assume that its mass acts from the centre of the tabletop. If you draw yourself a diagram you should see whats going on. Let me know if you don't!