7. A frictionless disc of mass 0.50 kg is moving in a straight line across an air table at a speed of 2.4 m/s [Right] when it bumps into an elastic band stretched between two fixed posts. If the elastic band exerts an average opposing force of 1.4 N on the disc for 1.5 s, what will be the final velocity of the disc? [4 marks] 8. A bomb initially at rest on a smooth, horizontal surface is exploded into three pieces. One piece (3 kg) flies off at 12 m/s [60N of E] and another 2.0 kg piece flies off at 20 m/s [E]. Determine the direction of the third piece which has a mass of 2.2 kg. [6 marks]