code for diagrams

> para:=plot([10*t,-4.9*t^2+19.6,t=0..2],thickness=3,
xtickmarks=[5,10,15,20,25],ytickmarks=[5,10,15,20],
labels=[X,Y],labelfont=[TIMES,BOLD,18], axesfont=[TIMES,BOLD,14],scaling=constrained):
plots[display](para,view=[-5..30,-5..30]);