d) Click on STOP. Record the two velocities (the initial velocity (magnitude and direction) of cart 1 and the velocity (magnitude and direction) of the combined carts after collision.) on your data sheet. e) Calculate the momentum (magnitude and direction) of cart 1 before the collision, and the total momentum (magnitude and direction) of the combined system after the collision. Record these values on your data sheet. As before, the magnitudes of these two quantities should be equal. Calculate the percent difference between the magnitude of the momenta