Recent content by justine411

Homework Statement (cos2x)^2 Homework Equations The Attempt at a Solution I'm not sure if it is cos^2(2x) or cos^2(4x) or what. Should I use an identity to simplify it to make it easier to solve? Please help! :)

nevermind, I figured it out on my own BOARD CLOSED

Homework Statement A wire of resistance 5.0 Ω is connected to a battery whose emf ε is 2.0 V and whose internal resistance is 1.0 Ω. In 2.0 min, how much energy is (a) transferred from chemical to electrical form in the battery, (b) dissipated as thermal energy in the wire, and (c)...

multiply everything out, like you did in your first suggestion, but then multiply those together ((3x^2-12x)(3x^2+6x)) then take the derivative.

Thanks! I wondered if it was a separable equation, but because the rate in is different from the rate out, isn't it linear, but not separable? That was sort of also holding me back...

I end up with integral ((400-6t)(y))prime=integral 0dt, and that can't be right. PLEASE I AM DYING TO KNOW WHAT I'M DOING WRONG!

sorry...it seems like a lot of people have looked at my problem...what is unclear about it? Why can't anyone help? Is there something I could do?

rate in= (4L/s)(0g/L)=0 rate out=(10L/s)(y(t)/(1000-6L)) then dy/dt-(10y)/(1000-6t)=0 I(t)=(1000-6t)^-10/6 (took a few steps to find, but I think it's right).

Homework Statement we have a tank with 400L of water with Cl, 0.02kg of Cl. Fresh water is pumped in at 4L/s and out at 10L/s. Find the amount of Cl in the tank as a function of t. Homework Equations Use of differential equations The Attempt at a Solution I set up V(t)=400-6t in...

I understand calculus, at least derivatives and integrals, so you can move it there if you want. Thanks SO much for your help. I thought it belonged here because it was in a chemistry tutorial, though it doesn't seem much like chem.

Homework Statement Vancouver Island has an area of 33000km^2 but no wombats. If we release a pair of wombats on Vancouver Island and their annual rate of increase is 50%, how many years will it be before the wombat population reaches one pair per km^2? Homework Equations [A]t=[A]oe^-kt...

Ok thanks! That's what I thought...hopefully I'll be able to get my prof to change my mark!

I just got my calculus midterm back, and I lost one mark on an area problem. I did the problem properly, but I may have made a mistake at the end. I end up with arctan1-1/2ln3-1/2ln1 (this step did not have an "x") I simplified this to pi/4-1/2ln3 (here, the grader put a 2 over my 3 in ln3)...

Ok. I'm still not getting the right answer for some reason! I have for my expression (Lm)+mc(T-273.15)=-mc(360.15-T) What am I missing now?

Sorry...it seems like some people have viewed, but haven't posted yet. Is there anything I did wrong or should add? Basically, I'm just trying to figure out how the latent heat of fusion is incorporated into the two equations I set up above.