[RPM] Potential Energy

[Varyon]

Originally Posted by sir_pudding

You would also need TL5 math and the ability to specify the angle and distance of the boulder relative to yourself. Arguably this is Forward Observer* and Artillery (Bombs).

* Due to the lack of a fire direction skill.

It certainly is lot easier to just do damage.

Depends on what magic requires of you. You're assuming it's "Create the boulder (2900)^(0.5) (call this hyp) yards away in that direction, in the air at an angle of (cos-1)(20/hyp) from my position." In that case, yeah, that's going to call for some math, although TL5 seems it might be a bit much - Pythagoras gives us the first equation, and I suspect Archimedes would have been able to get close enough to the second to work here, and they were both around at TL 2 (although they may have been using TL 3 mathematics).
(faux EDIT: With tools, this should certainly be doable at TL 2 using a cross-staff or similar)

However, I'd expect it to be more "Create the boulder 50 yards above a point 20 yards in that direction," in which case all you need to work out is the distance to the target (and maybe the distance to the ceiling if you're indoors, but this isn't as useful of a spell indoors, as you can't use gravity to as much of an advantage). The question is the skill you'd use for determining distance - any ranged combat skill might be sufficient, albeit likely at a penalty (this calls for more accuracy than typically needed to hit with an arrow) and a Per-based use, as would Forward Observer or whatever a commander uses to designate the target of a volley of arrows (either FO or Per-based Tactics). Observation could also work. The larger the boulder, of course, the less accurate you need to be. A better bet, of course, is to just designate the bridge (or an article of clothing, for a human target) and use Greater Sense Matter to get the exact range (Greater Sense Matter + Range + Subject Weight would be sufficient here).

Originally Posted by Anders

Or "Summon Miley Cyrus" and her wreckingball.

"Summon Ron Jeremy" could be comparable, and gets you a free use of Terror on those nearby, which might be more useful.