#pls help

42 messages · Page 1 of 1 (latest)

tardy pawn
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The length of the arc of radius R and angle α is L = αR.

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The angle must be in radians, of course.

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Well, what did you get?

tribal needle
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pi radians = 180°

tardy pawn
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Oh, interesting.
We have:
F(grav) = P = GmM/(R + h)^2
Thus:
P2/P1 = (R + h1)^2/(R + h2)^2 = ((R + h1)/(R + h2))^2
Since h1 = 0:
P2/P1 = (R/(R + h2))^2
Now, let's find h2.
R/(R + h2) = √(P2/P1)
(R + h2)/R = √(P1/P2)
1 + h2/R = √(P1/P2)
So, we get:
h = (√(P1/P2) - 1)R

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Well, you need to substitute the ratio.

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Note that your given ratio is P2/P1, but I used P1/P2 in the final expression.

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Yes.

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Yes, that's correct.

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No.

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Can you show your solution?

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Well, can you type it?

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Well, fine.
Let's find the mole fraction of C.
x(C) = n(C)/n(total) = n(C)/(n(C) + n(H))
n(C) = m(C)/M(C)
n(H) = m(H)/M(H)
So:
x(C) = (m(C)/M(C))/(m(C)/M(C) + m(H)/M(H)) = (150 g/(12 g/mol))/(150 g/(12 g/mol) + 50 g/(1 g/mol)) = 0.2 = 1/5
Thus:
x(H) = 1 - x(C) = 1 - 1/5 = 4/5
So, the ratio of carbon to hydrogen atoms in our compound is 1:4. So, it's methane.

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Well, a line can only lie in zero, two or three quadrants.
For the three quadrants, the conditions are the following:

  1. Slope is neither 0 nor ∞.
  2. Line doesn't pass through the origin.
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Yeah, that's a horizontal line.

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No, A is a vertical line.

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Well, have you simplified all the equations?

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No, C passes through the origin.

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Yes.

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Can you write the simplified equations of each line?

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Well, write all four.

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Yes.

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Hm... Don't know, honestly.

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No, sorry, still not sure.

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Oh, easy enough.
Solubilities (s) are given per 100 g of the solvent (H2O in our case, obviously). So, we make a proportion:
s(salt)/(100 g) = m(salt)/m(water)
As m(water) = m(sol.) - m(salt):
s(salt)/(100 g) = m(salt)/(m(sol.) - m(salt))
Now we find m(salt) from here.
(m(sol.) - m(salt))/m(salt) = 100 g/s(salt)
m(sol.)/m(salt) - 1 = 100g/s(salt)
m(sol.)/m(salt) = 100g/s(salt) + 1
m(salt) = m(sol.)/(100g/s(salt) + 1)
Now just substitute the values.

exotic sage
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in which class are u?

tardy pawn
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Hm, let's see. I will denote molality by b, though.
b(NaOH) = n(NaOH)/m(H2O) = c(NaOH)V(sol.)/(m(sol.) - m(NaOH)) = c(NaOH)V(sol.)/(ρ(sol.)V(sol.) - n(NaOH)M(NaOH))
Now, let's divide the numerator and denominator by V(sol.).
b(NaOH) = c(NaOH)/(ρ(sol.) - (n(NaOH)/V(sol.))M(NaOH)) = c(NaOH)/(ρ(sol.) - c(NaOH)M(NaOH))
And now we divide the numerator and denominator by c(NaOH).
b(NaOH) = 1/(ρ(sol.)/c(NaOH) - M(NaOH)) = 1/(1.12 kg/l/(3 mol/l) - 0.04 kg/mol) = 3 mol/kg

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The answer I got is exact.

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Maybe you rounded somewhere?

exotic sage
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they are teaching u this in class 9th?

tardy pawn
tardy pawn
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Oh, right... Well, then I don't know.

tribal needle
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ar(FGDE) = 83 + 17 = 100
ar(EFD) = ar(DFG) = 100/2 = 50
ar(ADF) = ar(EFD) - ar(DEA)
ar(ADF) = 50 - 17 = 33
ar(ADF) = ar(ABF) + ar(DCF)
ar(ABCD) = ar(ADF) + ar(ABF) + ar(DCF)
ar(ABCD) = 33 × 2 = 66 cm²

exotic sage
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ic

glacial flameBOT
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@warm flume has given 1 rep to @tribal needle

tribal needle
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urwelcome

tribal needle
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the thing I observe is that
ar(EDB) = ar(EDC) = ar(AEB) = ar(AEC)

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@mossy flicker how did u get b?

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this

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but you said it here?

mossy flicker
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wow you guys are quick to respond