Static Equilibrium: Max Distance of Top Brick Beyond Table Edge

[future_vet]

Homework Statement

Consider two identical bricks, each of dimensions 20.0 cm x 10.0 cm x 6.0 cm. One is stacked on the other, and the combination is then placed so that they project over the edge of a table. What is the maximum distance that the top brick can extend beyond the table edge without tipping?

Homework Equations

I don't really know...

The Attempt at a Solution

I would say at 10 cm, because that's where the center of gravity is. But it sounds too simple to be true... =/

Thanks!

 

[bdrosd]

It does sound too simple, are you sure that the two bricks are alligned edge to edge? Could one extend beyond the other?

 

[future_vet]

No.. they are one on top of the other... I guess I'll just keep 10 as the answer.

Thanks!

 

[Doc Al]

I highly doubt that the bricks are aligned with each other--kind of a pointless problem in that case, since the answer would not depend on the number of bricks. I would assume, as bdrosd suggested, that one brick can extend beyond the other.

Now to solve this, use the same reasoning that you used with one brick, only apply it twice. The center of mass is key. Hint: Start with the top brick and work your way down.

 

[hage567]

I don't think they are aligned either. It says how far can the top brick can extend beyond the table edge without tipping, which to me would suggest that the lower brick doesn't move.

 

[Doc Al]

I'd say you can arrange both bricks anyway you want to maximize the overhang of the top brick with respect to the table edge.

 

[Kaal]

So what was the correct answer because I have the same question and I don't Know how to solve it ..really need help!

 

[Doc Al]

So what was the correct answer because I have the same question and I don't Know how to solve it ..really need help!

Give it a try. Several hints were given in this thread. (Try it with one brick first.)