(adsbygoogle = window.adsbygoogle || []).push({}); Can this problem be done????

I just took a test with this problem on it (50% of the test grade) but I don't know if it can even be done or not.

We have a space craft landing on Mars. The space craft is landing "steadily at 1 m/s". It's basically a conic section with a "shell" around it (picture a thick vertical cylinder with inside diameter increasing except that the hollow part is the outside, not inside). It has rotors on the bottom which pull the air through the hollow part and accelerate it and push it out the bottom to balance out the force of gravity on the craft. The speed of the air going in from top and the area of the top hollow part are given. We need to find the speed of the air coming out of the bottom and the area of the hollow part where the air comes out from the bottom.

I don't know if this problem is right or wrong because the area*velocity has to be a constant (conservation of mass), but the area itself doesn't have to be a constant, nor does the velocity.

Conservation of mass:

(pAV)1 = (pAV)2

where p is the desnsity.

The density cancels out and we're left with

(AV)1 = (AV)2

We need one (area or velocity) to solve for the other.

I'm not going to go through everything I did on the test, but just give me your thoughts about this problem.

PS. This is a fluid mechanics class.

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# Homework Help: Can this problem be done?

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