## mariomintchev Group Title For #9, will I always get the right answer if I take the volume (32), divide it by the pressure (4), and multiply it by the rate (2)? 2 years ago 2 years ago

1. mariomintchev

2. mariomintchev

Because I get the right answer doing that with this problem...

3. KingGeorge

I don't think so. I'm pretty sure that's an artifact of $$2^2=4$$. Or something similar.

4. mariomintchev

what do you mean?

5. KingGeorge

Well, if we do the actual problem out, we get that $$c=128$$. Then, we have that $dV=-\;{128 \over P^2} dP$We know that $$dP =2$$ and $$P=4$$. Solving, we find that $$dV =-16$$. So really, it seems like it's because everything is just a power of two.

6. mariomintchev

i see

7. KingGeorge

For a counterexample, let $$V=40$$. Then we get that $$dV =-35/2$$ using the method I wrote out. Using your hypothetical method, we get that it would be $$-20$$.

8. mariomintchev

haha i like creating my own ways to solve things.