An air track with a mass of 500 grams is moving to the right with an initial speed of 0.50 m/sec. it collides perfectly elastically with a second cart which has a mass of 300 grams and is initially at rest. a.) what is the final speed of the 500 gram cart after the collision? b.) what direction is the 500 gram cart moving after the collision? c.) what is the final speed of the 300 gram cart after the collision? d.) what is the direction of the 300 gram cart after the collision?