[kjkjadksj]

How big a trebuchet would be needed to chuck a cubesat directly into LEO?

[chainingsolid]

cubesat + small rocket. Orbital mechanics require a burn at a later time in the orbit, to avoid coming back to say hello again to Mr. Trebuchet (Ignoring Earth's rotation)

[00N8]

100 or 200 km tall at point of release ought to do it.

[NetMageSCW]

The tip would still have to be doing 7 km/s.

[NetMageSCW]

Lookup SpinLaunch.