mjhjmtu

I've plotted the following graph, using tikz:

But I don't know how to make the vectors end exactly on the circle. Is there any simple way to do it?

CODE

documentclassstandalone
usepackagetikz
usetikzlibrarypositioning% To get more advances positioning options
usetikzlibraryarrows
usepackagemathtools
begindocument
begintikzpicture
draw[step=1cm,gray!25!,very thin] (-5,-5) grid (5,5);
draw[thick,->] (-3,0) -- (3,0) node[anchor=north west] x axis;
draw[thick,->] (0,-3) -- (0,3) node[anchor=south east] y axis;
draw[thick,->] (0,0) -- (2,2) node[midway,above] $veca$;
draw[thick,->] (-2,0) -- (2,2) node[midway, above] $veca'$;
draw[blue, thick,->] (-2,0) -- (0,0) node[midway, above] $Delta x$;
draw[red, thick] (0,0) circle (2 cm);
endtikzpicture
enddocument

You could use polar coordinates. And you do not need the libraries you are loading here, and in any case I would prefer arrows.meta over arrows. mathtools is not used either. And I would label repeating coordinates such that the diagram becomes easier to adjust.

documentclass[tikz,border=3.14mm]standalone
begindocument
begintikzpicture[>=latex]
draw[step=1cm,gray!25!,very thin] (-5,-5) grid (5,5);
draw[thick,->] (-3,0) -- (3,0) node[anchor=north west] x axis;
draw[thick,->] (0,-3) -- (0,3) node[anchor=south east] y axis;
draw[thick,->] (0,0) coordinate (O) -- (50:2) coordinate (oc) 
node[midway,below] $veca$;
draw[thick,->] (-2,0) coordinate (L) -- (oc) node[midway, above] $veca'$;
draw[blue, thick,->] (L) -- (O) node[midway, above] $Delta x$;
draw[red, thick] (O) circle (2 cm);
endtikzpicture
enddocument