# Terminal velocity and air resistance for diffenrent masses

Discussion in 'MCAT Study Question Q&A' started by m25, Sep 4, 2014.

1. ### m25

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So heavier objects fall faster than lighter objects because heavier objects have greater terminal velocity.
But if the fall distance is so short that neither objects reaches terminal velocity before hitting the ground, would both of the objects hit the ground at the same time? Will they be experiencing the same acceleration before one of them reaches terminal velocity?

In other words, is the "heavier objects fall faster than lighter objects when there's air resistance" statement only true if they reach terminal velocity before hitting the ground?

2. ### type12 5+ Year Member

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Your first phrase is incorrect in the sense of causes: it is true heavier objects fall faster, which means they have greater terminal velocity, but one does not cause the other. Instead, it is because the net force results in a different acceleration. Also, this is only true if there is a force to counter gravity, which would be air resistance on earth.

On earth, objects of different shapes and densities will have different air drags (aka air resistance); as a result, the F side of F = ma will have different values (i.e., mg - F_drag_1 vs mg - F_drag_2).

So, in short, no, it's not true only if they hit terminal velocity.

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