tmax = 10;
g = 9.8;
l = 1;
pendulum = Module[
   {g, l},
   ParametricNDSolve[
    {
     y''[t] + g/l Sin[y[t]] == 0,
     y[0] == 0, y'[0] == 1
     },
    {y},
    {t, 0, tmax},
    {g, l}
    ]
   ];
Animate[
 Graphics[
  Rotate[
   {Line[{{0, 0}, {0, -1}}], Disk[{0, -1}, .1]},
   Evaluate[y[g, l] /. pendulum][t],
   {0, 0}
   ],
  PlotRange -> {{-l, l}, {-l - .5, 0}}
  ],
 {t, 0, tmax},
 AnimationRate -> 1
 ]