A student holds a water balloon outside of an open window and lets go. The window is 10 meters above the ground, and the balloon is falling under the acceleration of gravity, which is 9.8 m/s2. There are two equations that can be used to describe its motion over time:
x=x0+v0t+12at2
v=v0+at
Would the balloon hit the ground before or after 1.0 s of falling? Which equation did you use to decide, and what comparison did you make to determine that it would or would not hit the ground by then?
Use 3–5 sentences to explain your reasoning.
1 answer
The balloon would hit the ground before 1.0 s of falling. I used the equation x=x0+v0t+12at2 to determine this. Since the initial velocity (v0) is 0 m/s, the equation simplifies to x=x0+12at2. Since the initial position (x0) is 10 m and the acceleration (a) is 9.8 m/s2, the equation becomes x=10+12(9.8)(1.0)2, which equals 28.4 m. Since this is less than 10 m, the balloon will hit the ground before 1.0 s of falling.
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