So, no suggestions as to adding speed to levitation?
I guess there is Movement power, with the added benefit that, due to magic, there are not increasing trouble with maneuvering.
So if I use Levitate on an object and then start tugging it, I can't move it? - But this is in direct conflict with the rules regarding using Levitate on a person. They get to roll strength+body vs. Forcex2 don't they?
That implies being able to move the object levitated in another direction, by applying enough force. In that case, applying force in the same direction should add the powers.
Example: Motorcycle jumping between skyscrapers at 100 km/h (before movement power).
The rider casts levitate on his bike, since its kinda risky business to do this without it... And since he is willing the bike in the direction he wants, but not letting it lose traction (while on the roofs), the power of the levitation spell should help the bike in acceleration and jumping length. Beyond the minimum speed still maintained by the levitate spell when the bike loses the rest of its own momentum.
And again, if I want to fly along with Levitate, but start taking bullets, I want to drop to the ground at near falling speeds, and then stop the fall using levitate. - But since force CAN affect levitate, in this case I would be wise to allow a safe distance to decelerate again or I'd hit the ground.
So the power of Levitate can probably be figured in newton, since we are given a maximum weight and speed to work with.
Of course this is unlikely to be relevant in most campaigns...