lewis.h
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Object A and Object B have the same shape and size, but Object A is double the mass of Object B.

Will object A reach terminal velocity quicker or slower than object B’s , and how will the magnitudes of these terminal velocities compare? Why ?

I mean, surely object A will reach terminal velocity faster than object B and have a smaller terminal velocity, as it’s drag will be much greater than Object B’s as drag is directly proportional to the density of an object , but equally object B will thus be accelerating for longer, so wouldn’t object B’s terminal velocity be greater than object A’s as it’ll take longer for its downwards resultant Force to decrease so that the object has a zero resultant Force (as opposed to a non-zero resultant Force) ?

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Joinedup
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Not sure where you heard that drag is proportional to density... but I'd try forget it before doing any exams.

I'd say that same shape and size means same cross sectional area... at a given velocity objects with the same cross sectional area will experience the same drag.

Double mass means double weight force

terminal velocity is reached when drag is equal to weight so the object with the greater mass will have the greater terminal velocity... and it reaches that greater velocity by accelerating for a greater length of time.
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lewis.h
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(Original post by Joinedup)
Not sure where you heard that drag is proportional to density... but I'd try forget it before doing any exams.

I'd say that same shape and size means same cross sectional area... at a given velocity objects with the same cross sectional area will experience the same drag.

Double mass means double weight force

terminal velocity is reached when drag is equal to weight so the object with the greater mass will have the greater terminal velocity... and it reaches that greater velocity by accelerating for a greater length of time.
Isn’t drag directly proportional to V^2 ?

So if the heavier object reaches a fast speed much quicker than object B does, wouldn’t that mean it’s drag will increase much quicker too,so it’ll reach terminal velocity faster ?

Thanks.
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