Rachel's crew is finally successfully in shooting the firework. They shoot it to its maximum height in 7 seconds and it explodes sending fragments scattering in horizontal directions all around at a speed of 20 meters per second. In answering the questions below,assume that air drag is negligible. What will be the acceleration of the fragments as they fall vertically? Assuming that they all fall from the same maximum height,how long will it take the fragments to hit the ground?