For this problem, we want to see the effects of trying to balance two masses on a lever. (What class of lever would this be?) One of the masses is exactly double the other.

Here are some photos of the original configuration of the ruler and the wooden prism.

A still from the video

View of the ruler balancing from directly above the ruler

What inch or centimeter mark will the prism be under to balance the ruler once the pennies are added?

I think it would have to be at the 4 in mark assuming the ruler balances correctly at exactly 6 inches. If two pennies have a value of zero each and one penny has a value of 12 the mean would be 4. I did not do any physical test of this so I guess that is just a hypothesis. let me know.

I think it would have to be at the 4 in mark assuming the ruler balances correctly at exactly 6 inches. If two pennies have a value of zero each and one penny has a value of 12 the mean would be 4. I did not do any physical test of this so I guess that is just a hypothesis. let me know.

It is a reasonable guess. I will be posting the solution which, I will admit, surprised me a bit. Much learning left to do for me, it seems.

Thanks for the comment.