A moving object transfers its force to the second object and itself comes to rest. Did you understand that? No? But you will once you play this little game with marbles.
The things you need:
1. Clay or plasticine
Step 1: Take two broomsticks and bend them around two centimetres in the centre.
Step 2: Seal the ends with clay or plasticine and apply some in the centre for support. The ends should be three centimetres higher than the middle. Keep five millimetres of distance between the two broomsticks for the marble to roll in between.
Step 3: Now place three marbles in the centre over the bend and roll another one from one end. You will see that on impact only one of the three marbles moves.
Similarly, if you roll two marbles, on impact only two of the three marbles in the centre will move. This explains the law of conservation of momentum according to which a moving object transfers its force to the second object and itself comes to rest.