What is the acceleration of a falling object from a balloon?

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The discussion revolves around calculating the time and speed of a package dropped from a hot-air balloon ascending at 12 m/s from a height of 80 m. The initial upward velocity of the package is 12 m/s, and it takes approximately 1.22 seconds for the package to stop ascending before it begins to fall. After reaching its peak height of about 87.35 m, the package then falls under the influence of gravity, taking about 4.22 seconds to hit the ground, resulting in a final impact speed of approximately 41.38 m/s. The conversation emphasizes the importance of understanding the initial conditions and the effects of gravity on the package's motion. Overall, the calculations highlight the interplay between initial velocity, gravitational acceleration, and the time of descent.
  • #31
SteamKing said:
I think here, instead of introducing spurious negative signs, it would be better to use g = -9.8 m/s2 along with the distance fallen of -87.347 m.
v02 still comes out positive.

But won't it be imaginary since ##v_0## is still negative?

SteamKing said:
The change in position will also be negative since the package was 87.347 m above the ground before it fell.

But then you'd have to move the negative displacement to the other side, making it positive.
 
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  • #32
Well, anyway, thank you so much for everything. You and everyone have been a big help to me with my self-study. Without this forum, I don't believe I would be able to learn physics on my own. So... thank you. :)
 
  • #33
Eclair_de_XII said:
But won't it be imaginary since ##v_0## is still negative?

The equation is v2 = u2 + 2 a s

There is no negative sign on the velocity terms. The product of -9.8 and -87.347 is also positive.

But then you'd have to move the negative displacement to the other side, making it positive.

Not if you take x = 0 being the ground and x0 = 87.347 m as the height from which the package started falling. Here, v0 = 0 and g = -9.8 m/s2, making the equation:

x - x0 = v0 t + (1/2)*g*t2 → 0 - 87.347 = (1/2) * (-9.8) * t2
 

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