Question

Sir I want to explain momentum of center of mass to my students.Please give any experimental Ideas...

Answer 1

at what level do you want to do this ?
One way I've used is to use a rubber hammer and throw it safely a short distance. Do it by throwing through the centre of mass - the balancing point, and see that the hammer doesn't spin much, if at all. Then, through it from one end and see that as it moves it also turns, and probably turns around the centre of mass. On a board, this can be drawn in a couple of minutes using a very simple shaped hammer (as long as it is not symmetrical). Demo probably about 15mins with "arguing and waffling time".
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Answer 2

I agree with @osprey. You could also use water bottles filled to various heights and (depending on the ages of your students) have them flip them in the air in an attempt to get them to land rightway up. The amount of rotation depends on the water level (and therefore center of mass). Only a precisely filled bottle will land rightway up. (Everyone's playing this game nowadays, it gets annoying in the hallways, so be warned.)

Answer 3

The idea of water bottles sounds hilarious. I won't be trying it, as I find bottles of fluid can be very awkard to handle. the centre of mass keeps MOVING !!!!! There's also a chance of getting soaked.
With a rubber/plastic/polystyrene claw hammer (no symmetry very much) and a bit of care, you've got some control over the mayhem.