Answer:
0.35 s
Explanation:
The water balloon is a projectile in free fall, meaning that the only force on the balloon is gravity. Since the balloon has a constant acceleration, we can use kinematic equations, also known as SUVAT equations, to model the motion. In this case, we will use:
v = u + at
where
In the vertical direction, the final speed of the balloon is v = 0 m/s, and the initial speed is u = 4.2 m/s sin 55°. The acceleration is gravity, a = -9.8 m/s². Plugging in values and solving for time:
v = u + at
0 m/s = 4.2 m/s sin 55° + (-9.8 m/s²) t
t = 0.35 s