A projectile is shot with initial velocity 20.0 m/s at launch angle ? = 60.0? up from horizontal. At the very top of its trajectory, the shell explodes into two equal-mass fragments. One fragment has velocity equal to zero immediately after the explosion, and it drops straight downward.
(a) How far from the gun does the other fragment land? Assume the ground is flat and that air drag is negligible.
(b) By how much does the mechanical energy of the two-fragment system change, right after the explosion, compared to the mechanical energy of the shell when it was fired from the ground?