Clear[v];
ti=0.;tf=5.0;delta=1.0;
v[ti]=0;a=9.8;
Do[v[t+delta]=v[t]+a delta;Print[{t,v[t]}],{t,ti,tf,delta}]

ListPlot[{{0,0},{1.,9.8},{2.,19.6},{3.,29.4},{4.,39.2},{5.,49.}},
  PlotJoined->True,AxesLabel[Rule]{"t","v[t]"}];

Clear[x,v,a];
ti=0.;tf=5.0;delta=0.5;
v[ti]=0.;x[ti]=0.;a=9.8;delta=0.5;
Do[Print[{t,x[t]}];v[t+delta]=v[t]+a delta;
  x[t+delta]=x[t]+v[t+delta] delta,{t,ti,tf,delta}]

ListPlot[{{0,0},{0.5,2.45},{1.,7.35},{1.5,14.7},{2.,24.5},{2.5,36.75},{3.,
      51.45},{3.5,68.6},{4.,88.2},{4.5,110.25},{5.,134.75}},PlotJoined->True,
  PlotJoined->True,AxesLabel[Rule]{"t","x[t]"}];

Clear[x,v,a];
ti=0.0;tf=20.0;delta=0.5;
v[ti]=0;x[ti]=0;a=9.8;
Do[Print[{t,x[t]}];v[t+delta]=v[t]+a delta;
  x[t+delta]=x[t]+v[t+delta] delta,{t,ti,tf,delta}]

xdata=Table[{t,x[t]},{t,0.,5.,delta}]
Off[ General::spell, General::spell1 ]

ListPlot[xdata,PlotJoined->True,PlotJoined->True,
  AxesLabel[Rule]{"t","x[t]"}];

Table[5 i,{i,0,2}]

Table[5 i,{i,0,2,0.25}]