How can I do this?

<img src="http://i45.tinypic.com/2dumhi.png" border="0" />

How can I realize this "catapult"?

I've physics beahiovior but only with this doesnt' work. Can anyone help me?

You'll need it to face the other way. That's sort of just how physics works.

Anyway, here's a little example. I used a revolute joint to connect the pivot point to the teeter-totter itself (this is created in the event sheet). The two blocks have a drag-and-drop behaviour, and the bigger one has a density of 5. The floor and the pivot are set to immovable.

Thanks for capx. (i tried all action of physics behavior). The solution is really simple. for me does't work because i've platform behavior too.. I see now how to solve

I can't find a solution. Why platform contrasts physics?

the object appears heavier

You'll need it to face the other way. That's sort of just how physics works.

Though this thread has been solved, I'm just going to chime in by saying that made me laugh so hard that coke came out my nose!

GAMEGAMEGAME You can edit density in the properties panel

GAMEGAMEGAME You can edit density in the properties panel

Yes, i know. But if platform behavior is disabled this work fine! with platform enabled, doesn't work.

the property "density" of physics behavior has nothing to do!

I need platform for move my objects, how can i resolve this?

In the example given changing the blocks desnity to 0.2 and adding platform behaviour gives the same results as a block without platform behaviour and a density of 5.

You can also use the physics object as a stand-in for a platformer by simulating movement with forces and impulses, such when keydown apply impulse at 90 degrees to jump.

Platform and physics usually don't play well together.

The platform behavior is on all 3 objects. So i need a solution to work with both behaviors. Or I need to change all events with platform..