m=0.01;k=0.0000001;g=9.8;

sol=NDSolve[{m v'[t]==-m g-k v[t]Abs[v[t]],v[0]==500},v[t],{t,0,100}]

Plot[v[t]/.sol[[1]],{t,0,100},PlotRange->All]

k=0.000005;
sol2=NDSolve[{m y''[t]==-m g-k y'[t]Abs[y'[t]],y[0]==0,y'[0]==500},y,{t,0,100}];
tmp=y/.sol2[[1]]

Plot[{tmp[t]/10,tmp'[t]},{t,0,60},PlotRange->All]

data=Table[{t,tmp[t],tmp'[t]},{t,0,100,0.2}];

Directory[]

Export["air-resistance.dat",data,"Table"]