Consider Two Carts,of Masses M and 2m,at Rest on a Frictionless

Multiple Choice

Consider two carts,of masses m and 2m,at rest on a frictionless air track.You push the first cart for 3 s and then the other for the same length of time and with the same force.The final speed of the cart with mass 2 m is

A) one third the speed of the cart of mass m.
B) one fourth the speed of the cart of mass m.
C) one half the speed of the cart of mass m.
D) the same as the cart of mass m.