During a hot air balloon race one specific balloon, initially at rest, accelerate vertically upward at a constant rate of a=4.5 ft/s^2 when t0=42 s from the ground the surface, which is at an altitude above mean sea level of s0=3750 ft. When the balloon reaches an altitude of s=3850 ft the pilot drops a sandbag. Compute
a)speed of balloon (and sandbag) just before the sandbag is released at s=3850 ft;
b)the time, t when the sandbag is released;
c) maximum altitude reached by the sandbag
d) the speed of the sandbags just as it hits the ground (s=3750ft)