4. an object (object a) with a mass of 500 kg is traveling in a straight line from west to east at a constant velocity of 34 m/s. object a encounters a headwind blowing with a force of 25 n for six minutes and then proceeds to collide with a stationary object (object b) with a mass of 300 kg, thereby reducing the velocity of object a to 4 m/s. what is the final velocity of object b?