Cart 1 of mass m is traveling with speed 2vo in the +x-direction when it has an elastic collision with cart 2 of mass 2m traveling with speed vo in the same direction.
What are the velocities of the carts after the collision?
please hurry and answer

(a) calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 10.0 g. silver has 47 electrons per atom, and its molar mass is 107.87 g/mol. (b) imagine adding electrons to the pin until the negative charge has the very large value 1.00 mc. how many electrons are added for every 109 electrons already present