Momentum and Energy

Two fan carts labeled A and B are placed on opposite sides of a table with their fans pointed in the same direction as shown in the figure below. Cart A is weighted with iron bars so it is twice as heavy as cart B. When the fans are turned on, they provide a constant force of the cart independent of its mass. Assume that friction is small enough to be neglected. The fans are set with a timer so that after they are switched on, they stay on for a fixed length of time, Dt, and then go off.

(a) Just after the fans go off, which of the following statements are true about the momenta of the two carts?

(i) pA > pB
(ii) pA = pB
(iii) pA < pB

(b) Just after the fans go off, which of the following statements are true about the kinetic energies of the two carts?

(i) KA > KB
(ii) KA = KB
(iii) KA < KB