Air Resistance

[Hemichordate]

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So if know that if two objects with the same shape and surface area are supposed to have the same air resistance (regardless of mass), why does the heavier object have greater velocity when falling? Wouldn't that INCREASE its air resistance?

 

[raab32]

So the basic idea with air resistance is that an object will continue accelerating downward due to the gravitational force mg until air resistance counters the downward acceleration with an equal and opposite force. If Object A has a mass of 25 kg and Object B has a mass of 5 kg, the gravitational force for A will be 25*10 = 250 N, while on B it will be 5*10 = 50 N. Object A will continue accelerating until air resistance pushes back with 250 N of force, while Object B will fall until air resistance pushes back with 50 N of force. Therefore, A will be accelerating for a longer amount of time, causing it to have a greater terminal velocity than B.

 

[Hemichordate]

Ok. I see how A will have greater velocity, but will the magnitude of the air resistance acting on both A and B be the same?

 

[loveoforganic]

Only when they are at the same velocity. At the terminal velocity, the forces will differ.