Physics diagrams maker.?

[Aladin]

I want a software by which I can make physics diagrams.Samples are given below.

 

[PohTayToez]

I imagine, if you can't fine something just for physics diagrams, autoCAD would work pretty well.

 

[monoman]

I just use ms paint for basic diagrams like the one on the right, and a good one for graphs is autograph, where the graphs can be copied out of the program to a written document (e.g. word) or paint type program. i think this is free to download, but not sure i got it free from my college. definitely recommend this program anyway for basic or advanced purposes if you ever need any graphs for projects/ coursework etc.