Math & Science ⇒ Change Font for one Variable globally

[Singularity]

Is there a way to change all v variables in my entire document?

Let's say I was nearly done writing a long thesis proposal (and don't have enough time to go through the whole document changing all vs to another, less appropriate, letter). Let's say the proposal included the variables u and v. Let's also say that I don't like how the u and v look very similar (specifically, the v's bottom isn't very pointy). Is there a global way I could change all of the math vs (not vs in the text)?

Thanks.