Two carts 1 and 2 with masses m1 and m² are sitting at rest on an air track with an explosive substance glued between them. After the explosive goes off between the carts, What happens to the carts?
1) Both carts move in the same direction
2) Both carts move in opposite directions
3) Cart 1 moves and Cart 2 remains at rest
4) Cart 2 moves and Cart 1 remains at rest