Answer:
The time spent in air by the package is 1.5 s
Step-by-step explanation:
Given;
speed of the balloon, v = 7.0 m/s
distance traveled by the balloon, d = 21 m
The time spent by the object in the air is give by;
d = vt + ¹/₂gt²
21 = 7t + ¹/₂(9.8)(t²)
21 = 7t + 4.9t²
4.9t² + 7t -21 = 0
solve this quadratic expression, and the value of t will be
t = 1.5 s
Therefore, the time spent in air by the package is 1.5 s