It shows a mass at rest on a ramp. For most points I have been able to parameterise the coordinates (meaning that, for example, I can change the angle of the ramp or the mass size by changing a single parameter. The code follows:
I now want to add an arrow vertically downwards from the centre of the mass. The line
gives me this, but I have had to 'hard-code' the x-coordinate of the mass Centre. If I use
I get an error
Package tikz Error: Cannot parse this coordinate.
Also can someone explain how the relative coordinates in
work? I would have expected