Benedict is driving bumper car 1 with velocity v towards two of his unsuspecting classmates, Gabby and Zoe, in bumper cars 2 and 3, both siting at rest. The fenders of bumper cars 1 and 2 lock up after the two of them collide, and they move off towards bumper car 3 together. Assuming the final collision between carts 1+2 and 3 to be elastic, what speed does cart 3 have after the collision? Assume all three cars have roughly the same mass, m. 2