ST5.13 Carts, carts, carts, carts (2)

Consider two carts of masses m and 2m at rest on an airtrack. If you push first one cart for 3 s, then the other for the same length of time, exerting equal forces on each, the momentum of the light cart is
Incorrect
Incorrect
Correct
Incorrect
Incorrect

[There is ONE correct answer above. Choose the one you think is correct and press the "Check Your Answer" button below to see if you are right.]