Free-body diagram velocity vector

[alingy1]

My teacher gave me a solved problem to practice. There is a free-body diagram of a particle on a tilted plane. The resulting force points in the direction of the negative x-axis, aligned with the inclination of the plane.Am I the only one that thinks there could also be a velocity vector pointing in the positive direction? After all, the net force only represents acceleration.

 

[NasuSama]

It would be a lot easy if you upload the free-body diagram of that plane, so we can really help you.

 

[PhanthomJay]

Free Body Diagrams show only the forces and moments (torques) acting on the system or parts of the system. They do not show velocity or acceleration vectors, which, if needed for clarity,, may be shown in a supplemental
diagram or at least apart from the free body diagram itself.