[Railroad Handcar] [HINTS: It's important to recognize whether each velocity is specified relative to the cart or the ground and to distinguish between the reference frame of the cart before vs. after the mass is thrown. These are different if the cart's speed changes during the throw.] Please add: (d) In part (a), what is the velocity (speed & direction) of the thrown mass relative to the ground? How and why would the results of part (a) change if instead the mass were thrown out of the cart with a velocity of 2.00 m/s sideways relative to the ground? How would the throwing action be different as seen by someone riding on the cart?