A uniform rod AB of mass 3m, length 4l free to turn in a vertical plane about a smooth horizontal axis through A is released frm rest when horizontal.

When the rod first becomes vertical, a point C on the rod where AC=3l strikes a fixed peg.

Find the impulse exerted by the peg on the rod if

1. the rod is brought to rest by the peg

2. the rod rebounds and next comes to instantaneous rest inclined to the downward vertical at an angle pi/3.