Thursday

July 31, 2014

July 31, 2014

Total # Posts: 44

**Chemistry**

what effect does a catalyst have on entropy?

**U.S. History**

I can't think of ideas for this essay topic: What role does white resistance to integration play in the success of the civil rights movement by 1965?

**U.S. History**

I can't think of ideas for this essay topic: What role does white resistance play in the success of the civil rights movement by 1965?

**Chemistry Lab**

Nevermind I think i figured it out. But CaCO3 is supposed to react with water in the presence of CO2

**Chemistry Lab**

We did a lab where we reacted antacid with HCL and measured the pressure increase after the reaction. Then we found the percent concentrations of calcium carbonate of the antacid tablet. The question is: say the percent of calcium carbonate from trials 1 & 2 are consistent whi...

**Chemistry Lab**

We did a lab where we reacted antacid with HCL and measured the pressure increase after the reaction. Then we found the percent concentrations of calcium carbonate of the antacid tablet. The question is: say the percent of calcium carbonate from trials 1 & 2 are consistent whi...

**Chemistry**

Why does O3 have a dipole moment?

**Chemistry**

Ooh I forgot about that one. thank you

**Chemistry**

A beam of neutrons (mneutron = 1.6749 x 10^-24 g) has a velocity of 1.44 km/hour. What is the wavelength of the neutron wave? The answer is 993 nm. I tried to use 1/2mv^2=hc/lambda but I got 1483.5 m

**Chemistry**

When light of a wavelength of 125 nm strikes a certain metal, electrons having a velocity of 8.2 x 10^5 m/s are emitted from the surface of the metal. What is the threshold frequency of the metal? The answer is 1.9 x 10^15 s^-1 I'm not sure how to do this. The equations th...

**Chemistry**

nevermind I got it

**Chemistry**

If the wavelength of an electron is equal to the radius of the n=2 orbit in He+, what must the velocity of the electron be? The answer is 6.88 x 10^6 m/s How do I find this? I tried E = Z^2hcRh/n^2 and E= 1/2mv^2 with Z = 1, n=2, m=9.109E-31

**Science**

lysosomes they are organelles, though. I don't know if you meant cell or organelle. if you meant cell, I don't know the answer

**Chemistry**

Why does MgO have a higher melting point than CaS? They are both ionic compounds with the same charges, but CaS is heavier so shouldn't it have a higher melting point?

**Science**

Yes. Muscle cells use energy and need lots of ATP so it has large numbers of mitochondria

**Chemistry**

That is correct. The radius increases down and to the left of the periodic table

**Calculus**

Find the partial derivatives of f(x,y)=(sinx + y)^(y sinx)

**Calculus**

that doesn't mean it's convergent, necessarily. but i found it is actually convergent because if you divide by 1/2^n, which is also a positive term series, you get 9, which means the series is convergent.

**Calculus**

Is the series (8+1^n)/(1+2^n) divergent or convergent?

**Calculus**

What methods can I use to prove that the limit as (x,y,z)--> (0,0,0) of a function of 3 variables does not exist?

**Calculus**

series n=1 to n=inf 4/(n^2 - 36) what happens when n=6 and there is 0 in the denominator? do we just skip it?

**calculus**

76 and 100 are both divisible by 4 76/4 = 19 100/4 = 25 therefore 76/100 = 19/25

**Calculus**

I don't need the limit, I just want to know how to show it is in the indeterminate form.

**Calculus**

limit as x-> 0 (1+sinx)^(cscx) How do I show that this is indeterminate? Can I say that 1^(1/0) = 1^infinity?

**Calculus**

nvm

**Calculus**

How do I prove that the series ln(n)/(3n) is divergent?

**Calculus**

nvm i think it is absolutely convergent

**Calculus**

series: n=1 to n=inf of 6/(n^3-4) convergent or divergent?

**Calculus**

Yes. I found that the limit of the sequence goes to 0 and that it is a positive term series. Now what do I do?

**Calculus**

how do I know if the series ln(n)/(2n) is DV or CV?

**Calculus**

Squeeze law? then the limit is 0 right? -pi/sqrt(1-x) <= f(x) <= 0

**Calculus**

what is the limit as x goes to 1- of (arcsin(x) - pi/2 ) / sqrt(1-x) ? I tried using L'Hopital's and it doesn't work.

**math**

300/8 x 100 = 37.5 x 100 = 3750%

**College Algebra**

2y = 6 - 5x y = 3 - 5/2 x this is in the form y = mx + b where m is the slope and b is the y-intercept. therefore -5/2 is the slope, 3 is the y-intercept

**EXAM TMRW**

for the first one I got 332 kJ/mol E = hc/lamda E = (6.626E-34)(2.998E8)/(360E-9) E = 5.522 J To convert it to kJ/mol, multiply by 6.022E23 and divide by 1000 to get 332 kJ/mol

**Algebra check**

27) 10^-3 = x x = .001 28) yes 29) take ln of both sides. xln(8)= ln(5.2) x = ln(5.2)/ln(8) ~ 0.7928 30) raise both sides to the e e^ (lnx) = e^(5/8) x=e^(5/8) ~ 1.868

**Calculus**

Is sum of sin(pi/n) DV or CV? I don't understand why it is DV.

**Calculus - Series**

Why is the limit of the sum n=1 to infinity of ln(2(n+1))â€“ln(2n) divergent? I thought it would be -ln2 because all the other terms cancel out cancel out.

**Physics**

The intensity of sound from a source is measured at two points along a line from the source. The points are separated by 14.7 m, the sound level is 67.10 dB at the first point and 55.68 dB at the second point. How far is the source from the first point?

**Physics**

Use f=nv/(2L) f = 5*1.25m/s/(2*4.0 m) f=.781 Hz

**4th grade**

"Girl" and "lake" are nouns in the first sentence. "Fish" "river" and "lake" are nouns in the second sentence.

**9th grade**

Cons - a lot of waste material and pollution, coal mining accidents, black lung disease Pros - Abundant

**MATH PLEASE HELP!**

What is the question?

**biology**

organs?

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