g[t_]={0,-9.81};
v0={10,20};
v[t_]=Integrate[g[t],t]+v0

r[t_]=Integrate[v[t],t]

ParametricPlot[r[t],{t,0,4},AxesLabel->{x,y},PlotStyle->{Blue,Thick},LabelStyle->Directive[Large]]