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Mission VP10 Displacement and Time for a Projectile

 The Question

An airplane is flying horizontally across the sky at a constant speed. It drops a package from its cargo bin. By the time the package lands on the ground, the airplane is at the position shown. Assuming negligible air resistance on the package, the package would follow path ... .

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 Physics Rules

Independence of Perpendicular Components of Motion
Perpendicular components of an object's motion are independent of each other. For a projectile, the horizontal motion is independent of the vertical motion. The horizontal motion occurs at a constant speed. The vertical motion occurs with a downward acceleration. The two motions are independent of each other.

 Think About It

If we can assume negligible air resistance on the package, then the package travels as a projectile. The projectile's motion can be described as having a constant horizontal motion and an accelerated vertical motion. The constant speed in the horizontal direction means that in the same amount of time, the package will travel the same horizontal distance as the plane. Thus, at all locations in its trajectory, the package is directly below the plane. And when the package hits the ground, it will hit the ground at a location directly below the plane's location.

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