I'm just beginning to DM my first campaign, and one of my players asked this of me.
She plays an Orc with 20 strength, so theoretically I think she probably could drop-kick a Gnome, but I have no idea how to calculate it, or what kind of number I'd require her to roll on a check for it.
Forgive me if this is somewhere in the DM's Guide, I haven't been able to find anything.