# Where is the center of mass of this structure?

1. Nov 15, 2013

### Urmi Roy

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

So I'm taking the safe side by posting this question as a h/w problem, since even though its just to satisfy my curiosity, I don't want to take the risk of being penalized for putting a specific case like this one on another forum.

I'd just like to know how this stable structure is possible.

2. Relevant equations

I guess we're looking for its center of mass.

3. The attempt at a solution

Most of the mass would be concentrated in the foot on the ground/the foot above, but I'm not sure the math would work out!

Last edited by a moderator: May 6, 2017
2. Nov 15, 2013

### Simon Bridge

Not all the sculpture is above ground.
Imagine the falling figures foot has a steel core that is welded to steel I-beams that extend under the white paving stones... or just a big block of concrete.

Another example:
http://www.flickr.com/photos/russellstreet/4066480678/in/photostream/
It's called "Throwback" and I saw it installed - the big D is supposed to be a bit of architecture that got tossed there to stick up at about 70deg to the horizontal. The bottom "corner" is actually a huge block of concrete. The reaction from the surrounding ground keeps it upright.

Last edited: Nov 15, 2013
3. Nov 16, 2013

### CWatters

It might also be hollow. Bronze is quite expensive.

4. Nov 16, 2013

### Staff: Mentor

No doubt many have passersby have weighed down on the sculpture's arms to test his strength, or theirs, so he would need to be much stronger than might appear, to endow him with a longevity in this public space. http://physicsforums.bernhardtmediall.netdna-cdn.com/images/icons/icon6.gif [Broken]

Last edited by a moderator: May 6, 2017
5. Nov 16, 2013

### Simon Bridge

It is certainly hollow.
Test bronze statues near where you live.

6. Nov 16, 2013

### HallsofIvy

Staff Emeritus
Though if you want to test them by drilling a hole in them, do it late at night and make sure there are no policemen around!

7. Nov 16, 2013

### Simon Bridge

Recommend tapping as a hollowness test. ;)
Public display bronze statues ring hollowly when tapped but are still strong enough to be climbed on.