I'm making a golf template and need a way to use the distance of the mouse from the ball as a variable of how powerful the shot will be

https://en.scratch-wiki.info/wiki/Distance_to_()_(block)

Go to the workaround section and copy it.

@Dragonmyflesh offers a solid solution that is useful in many situations - d=√[(x2-x1)²+(y2-y1)²]

However, for the distance from a sprite to the mouse pointer you can simply use the build in distance block -