Friday

November 27, 2015
Total # Posts: 269

**math**

let θ(in radians) be an acute angle in a right triangle, and let x and y, respectively, be the lenghts of the sides adjacent and opposite θ. suppose also that both x and y vary with time how are dθ/dt, dx/dt, and dy/dt related?
*October 19, 2011*

**Algebra 2**

3 5 7 are odd and consecutive-- they add to 15 which is greater than 10 and less than 20.
*October 19, 2011*

**Calc**

let theta (in radians) be an acute angle in a right triangle, and let x and y, respectively, be the lenghts of the sides adjacent and opposite ?. suppose also that both x and y vary with time
*October 19, 2011*

**Algebra**

y- intercept is b in the formula y=mx+b hence your y intercept is 7/2.
*October 19, 2011*

**Algebra**

y=mx+b and m is the slope rearrange the equation so you can find what y equals. in this case you would rearrange it to equal y=-5x/2+7/2. so your slope is -5/2.
*October 19, 2011*

**Calculus**

Assume that x>0 and y>0. If y=5sqrt{x+9} and dx/dt = 2, find dy/dt when x=7.
*October 17, 2011*

**Algrebra**

Please advise on the following: From 1993 to 2003 the cumulative number N of AIDS cases in thousands can be approximated by, where corresponds to the year 1993. N = -2 x2 + 76x + 430, where x = 0 corresponds to. 1) Show how well the equation approximates the data. 2) Rewrite ...
*July 25, 2011*

**world issuse**

Don't kno the answe...pls tell me the answer
*May 24, 2011*

**math**

Probability: 11 out of 29; or 37.9310345%. Method: Take a sample of 100. 45 are men; 40% or 18 men wear glasses 55 are women; 20% or 11 women wear glasses. So out of 100, 18+11=29 wear glasses out of which 11 are women. Probability: 11 out of 29
*April 13, 2011*

**math**

-1/2, 1/7, 2/7, 6/7 Method: Negative (-1/2)is obviously smaller than positives. So that is the smallest. Then arrange the rest in order of the top (numerator), since the bottom (denominator) in each case is the same.
*April 13, 2011*

**algebra 1-B**

how to write 24th march 2011 in 5b letter without using number
*March 24, 2011*

**geometry**

A right triangle has a base that is 2 more than twice the height. Find the length of the base for the triangle. If the area is 30 square units.
*January 31, 2011*

**MATH !!**

could you also tell me what the series will be ? thanks.
*December 19, 2010*

**MATH !!**

n lim(n→+∞) ∑ (3/4)^k = k=1 the n is supposed to be above the sigma sign and the k=1 is supposed to be below the sigma sign. thanks.
*December 19, 2010*

**Please Help **

the n is supposed to be above the sigma sign and the k=1 is supposed to be below the sigma sign. thanks.
*December 19, 2010*

**Please Help **

n lim(n→+∞) ∑ (3/4)^k = k=1
*December 19, 2010*

**Calculus**

Use a simple area formula from geometry to find the area under function A(x) that gives the area under the function f(x) = 9 on the interval [2, x].
*December 19, 2010*

**Calculus**

Find all values of x, where the graph of y = [(5x^3)-(6x)+(8)] / (x^2) crosses its oblique asymptote.
*November 29, 2010*

**Calculus**

Find all values of x, where the graph of y = [(5x^3)-(6x)+(8)] / (x^2) crosses its oblique asymptote.
*November 29, 2010*

**calculus**

use the definition of the derivative to calculate f'(x), if f(x)= SQRT(2x) and find the equations of the tangent line and the normal line to the graph of f at x=2
*November 13, 2010*

**Physics-work,power,energy**

A 20 ton truck is pulling a 5 ton trailer.their common uniform velocity is 54 kmph.if the frictional force is 20N per both the truck and the trailer then power developed is?
*October 31, 2010*

**Chemistry**

0.2M
*October 10, 2010*

**algebra 1a**

Soybean meal is 18% protein, cornmeal is 9% protein. How many pounds of each should be mixed together in order to get a 360-lb mixture that is 10% protein? Cornmeal-how many pounds:__________ Soybean meal-how many pounds:______
*May 27, 2010*

**Math **

Soybean meal is 18% protein, cornmeal is 9% protein. How many pounds of each should be mixed together in order to get a 360-lb mixture that is 10% protein? Cornmeal-how many pounds:__________ Soybean meal-how many pounds:______
*May 27, 2010*

**English-please help**

To bring to your organization enthusiasm, dedication, responsibility, and good work ethic, combined with a desire to utilize my skills obtained through work experience. Is that correct sentense??
*May 10, 2010*

**English-please help**

I am reliable dishwasher seeking for a position of dishwasher where I can use my previous dishwashing experience for a leading restaurant. Is that correct sentense??
*May 10, 2010*

**English-plese hepl**

I am reliable dishwasher seeking for a position of dishwasher where I can use my previous dishwashing experience for a leading restaurant. Is correct sentense??
*May 10, 2010*

**math**

So i was working in the office with Matt today and he said the funniest thing. He said if you get 1 stick and hit a bird with it two birds will appear! But if you hit the two birds with 2 sticks a pineapple with appear. But if you eat the pineapple you will become the ...
*May 7, 2010*

**Physics **

The small archerfish (length 20 to 25 cm) lives in brackish waters of Southeast Asia from India to the Philippines. This aptly named creature captures its prey by shooting a stream of water drops at an insect, either flying or at rest. The bug falls into the water and the fish...
*April 17, 2010*

**chemistry**

When excess solid Mg(OH)2 is shaken with 1.00 L of 1.2 M NH4Cl solution, the resulting saturated solution has pH = 9.30. Calculate the Ksp of Mg(OH)2 I am not sure where to even begin on this problem.
*March 21, 2010*

**CHEMISTRY**

What is reaction between HI+HNO3
*February 21, 2010*

**English**

ut the words in correct sentence order. If necessary, change the form of the simple verb in boldface. Be sure to begin each sentence with a capital letter. Pay attention to the final punctuation. 1)be no, she. 2)don't no, you.
*February 10, 2010*

**English**

to Steve go City College. Steve goes to city college.is that right?
*February 9, 2010*

**English**

Put the words in correct sentence order. If necessary, change the form of the simple verb in boldface. Be sure to begin each sentence with a capital letter. Pay attention to the final punctuation. 1)be we library the in. 2at college be she the? 3)be no, she. 4)be he late ever ...
*February 9, 2010*

**probability**

1/36
*January 1, 2010*

**chemistry**

a 500 ml portion of .0020 M Na2C2O4 solution is able to dissolve .47g of MgC2O4. What is the Ksp for MgC2O4
*November 24, 2009*

**Social Science**

Can anyone help me get some points? What can the Church do today to make itself more relevant to Generation X?
*July 9, 2009*

**Algebra Honors**

The length of the base of a triangle is 4 times its altitude. If the area the triangle is 162 cm2, find the altitude.
*April 2, 2009*

**Chemistry**

PartA: What volume of 10.0M NaOH is needed to prepare a buffer with a pH of 7.79 using 31.52 g of TrisHCl? TrisHCl is a weak base and the molecular weight is 157.67 g/mol. I found the solution, it is 6.67 milliliters. The main question is:Part B: "The buffer from Part A ...
*March 1, 2009*

**CHemistry**

45.00 mL of 1.55×10^−2 M HI(aq) is mixed with 85.00 mL of 1.08×10^−2 M KOH(aq). What is the pH of the solution?
*February 18, 2009*

**Chemistry**

What is [H3O+] in a solution obtained by dissolving 215 mL HCl(g), measured at 23 degrees C and 757 mmHg, in 4.30 L of aqueous solution?
*February 14, 2009*

**Chemistry**

can u tell me what your final answer is? I got 7.96 * 10 ^5 ml.
*February 14, 2009*

**Chemistry**

thnx
*February 14, 2009*

**Chemistry**

How many millimeters of this solution should be diluted with water to produce 650 mL of a solution with pH= 11.50? 6.8% ammonia (d= 0.97g/ml)
*February 14, 2009*

**Chemistry**

I thought for the density, the calculation would be as follows: 0.15gKOH/g---> 1g of solution, density=1.14 g/ml.......0.15g/(1g/1.14g/ml) to get 0.171 g/ml. and then I thought molarity for [OH^-] was 2.51 * 10^-3. The proper set up I got like 3.66 g/? mL. I might be wrong...
*February 14, 2009*

**Chemistry**

How many millimeters of a 15.0%, by mass solution of KOH(aq)(d = 1.14 g/ml ) are required to produce 26.0 L of a solution with pH = 11.40?
*February 14, 2009*

**Chemistry university level**

what mass of ethylene glycol, the main component, of antifreeze, must be added to 10.0 L water to produce a solution for use in a car's radiator that freezes at -23.3 degree C? Assume the density for water is exactly 1 g/ml.
*January 27, 2009*

**chemistry**

what is the lewis dot structure for SO4 -2 and the ideal bonds, mollecular structure and hybrid orbitals?
*January 15, 2009*

**Organic Chemistry**

i am not able to get the proper name but i can tell the structure i.e. ch3 ch3-ch2-ch2oso3
*January 7, 2009*

**chemistry**

the wander walls force of attraction increases,it become more stable and it requires less energy.
*January 7, 2009*

**Chemistry...Please Help**

GK, why don't you write the concentration of water for (e)?
*January 6, 2009*

**Statistics**

The percentage of adults who have been told at some point that they have hyptertension is 23.53%. If 10 adults are randomly selected, what is the probability that at least 8 have been told that they have hypertension?
*October 9, 2008*

**Chemistry**

Draw the Lewis structures for BrO3- and ClO4- and indicate their correct number of additional resonance structures. I'm a little confused about this. For example, I've got the correct original form of BrO3- down. Where all 3 O atoms are single bonded to Br, and the Br ...
*September 28, 2008*

**history**

I need information on Bull Capital Rampurva Maurya 323. thank you
*June 21, 2008*

**Chemistry**

Can someone please explain to me whats the difference between a buffered and non-buffered solution?
*March 23, 2008*

**Chemistry**

Yes I know it will be m=1. But what if I have something like log (base 1/4) 0.33 = m Then how would I solve something like that.
*March 11, 2008*

**Chemistry**

I haven't calculus in a while. So can someone please help me with this, its for rates: log (base 1/4) 0.25 = m I know that m = 1, but how would I solve for it using the log method.
*March 11, 2008*

**Chemistry**

I need help distinguishing between nucleophiles and electrophiles. Like one of the examples I am given shows methanal, chloroethane, and methanamine. Now it says methanal is electrophilic because the carbonyl group is polar since the more electronegative oxygen atom has a ...
*March 5, 2008*

**Chemistry**

I understand why PCl3 is zero order, but I don't get why Cl2 is second order.
*February 27, 2008*

**Chemistry**

In the reaction PCl3 + Cl2 ---> PCl5. If the rate doesn't increase when the concentration of PCl3 is doubled and the rate increases by a factor of four when the concentration of Cl2 is doubled, how would I write the rate law for the reaction?
*February 27, 2008*

**Chemistry**

If I2 reacted with hexane, how would we know, which carbons the Is go on? Would only one of the iodine go to the hexane and the other form HI, or would they both join and H2 is a by-product?
*February 11, 2008*

**Chemistry**

Sorry, I meant hexane and not toulene. For hexane, I would expect a reaction to occur, but the colour stayed dark purplish. Would HI form here?
*February 10, 2008*

**Chemistry**

For a lab, I had to react toulene with 1% I2 in dichloromethane. Would HI form as a result of this? Logically, I think there would be no reaction because toulene looks too stable. But a colour change occured. Why would this happen?
*February 10, 2008*

**Chemistry**

Nevermind.
*February 6, 2008*

**Chemistry**

Given the weight of phenacetin and its percentage yield...how would I calculate its melting point?
*February 6, 2008*

**Chemistry**

Write the structure for the alkane: molecular mass = 72 u; forms four monochlorination products. Well since its 72u and its an alkane, I figured out that the formula is C5H12. But what does it mean that it "forms 4 monochlorination products"?
*January 31, 2008*

**Chemistry**

If I am given a molecular hydrocarbon structure, how would I be able to tell how sp3 hybridized carbons it possesses? Like my current question asks How many sp3-hydridized carbon atoms does 11-cis-retinal possess?
*January 27, 2008*

**Antiderivatives**

I can't figure this one out, the antiderivative of x^-1. I thought it would be c, but the derivative of c is zero.
*January 22, 2008*

**Math**

4/5 - 1/2 Find a common denominator and solve.
*January 10, 2008*

**Chemistry**

Thanks, for the help, although the last one doesn't look right, I understand it now. Thank You.
*January 10, 2008*

**Chemistry**

Can someone explain for organic chemistry naming, when something would be given something like "iso" in it or when we would say "s-butyl" or "t-propyl" etc., with "s" meaning secondary and "t" meaning tertiary.
*January 10, 2008*

**Chemistry**

How can I tell whether something is a weak, strong, or non-electrolyte? I know non-electrolytes do not ionize, strong almost completely ionize and weak only partially. But how would I be able to tell? Like, something like KOH is a strong electrolyte because it can ionize into ...
*December 16, 2007*

**Chemistry**

In a thermochemistry experiment the reaction of 0.0857 g of an unknown metal and an excess of 4.0 M HCl resulted in a 0.210 mL decrease in the volume of an ice/water mixture. Calculate the enthalpy of this reaction per 1 g of metal reacted. Needed data: density of water at 273...
*December 1, 2007*

**Chemistry**

The reaction between 0.055 g of calcium with an excess of water was carried out in an ice calorimeter. The volume of water in the calorimeter decreased by 0.20 mL during the reaction. Calculate the enthalpy of the reaction (in kJ/mol).
*November 24, 2007*

**Chemistry**

Oh, alrite so then heres what I get. 2 Cl(g) --> Cl2(g) exo-on H2O(l) --> H2O(g) endo-by 2 H2(g) + O2(g) --> 2 H2O(l) exo-on 2 Li(s) + H2O(l) --> 2 LiOH(aq) + H2(g) endo-by 3 NaN3(s) --> Na3N(s) + 4 N2(g)endo-by
*November 20, 2007*

**Chemistry**

When given a chemical reaction, how would I know whether a reaction is endo or exothermic and whether work is done on the system or by the system. Without using any calculations. So I have a couple reactions which I have to use chemical reasoning to to determine. 2 Cl(g) -->...
*November 20, 2007*

**Chemistry**

You have to determine the molar mass of CaCO3, by getting the molar mass of Ca and the molar mass of C, and the molar mass of O multiplied by 3 (since there are 3 oxygen atoms). You would get 100.087 g/mol. You would then do the mass/molar mass. 30.6/100.87 = your answer
*November 20, 2007*

**Chemistry**

How did you get 1 cal/g*c....is that a calculated constant or is manual conversion required? The answer I get using your method is 96.4kg, which is correct.
*November 20, 2007*

**Chemistry**

Wait, I did it wrong. q = mH(Tf - Ti) m = q/H(Tf-Ti) m = 675/[4.18x7] m = 23.06 But its still the wrong answer.
*November 20, 2007*

**Chemistry**

m = q/[(H)(Tf-Ti)] m = (4.18)[(675)(37-30)] m = 8.84 x 10^-4 I'm pretty sure this is wrong.
*November 20, 2007*

**Chemistry**

A person falls in water at 0 degrees C. After 20 minutes of exposure, they are suffering acute hypothermia, as their core body temperature has dropped to 30.0 degrees C. Assume that a person’s heat capacity can be approximated by the heat capacity of water, 4.18 J/g/oC. ...
*November 20, 2007*

**Chemistry**

So for ii) If HClO2 is the stronger base, then does that mean that ClO2 is also the stronger base?
*November 20, 2007*

**Chemistry**

Sorry, for iii) I meant that I think Cl3CCOO- is the stronger base.
*November 20, 2007*

**Chemistry**

For each of the pairs of bases below, choose the stronger base: (i) NH2- or NH3 (ii) ClO3- or ClO2- (iii) Cl3CCOO- or Cl2HCCOO- For i) I think it is NH2-, because it has a stronger ability to attract an H+ atom to become de-ionized. For ii) I don't know how to determine it...
*November 20, 2007*

**Chemistry**

Do I have to make equations and see which one forms a precipitate again? I don't think its H2CO3 or HCl because that would not minimize the effect of acid rain. So its either the 2 bases or CCl4. CCl4 + SO2 ==> CO2 + SCl4 ClOH + SO2 ==> CO2 + SOH Ca(OH)2 + SO2 ==>...
*November 18, 2007*

**Chemistry**

Stelco has been recently legislated to reduce total SO2 emissions from iron smelting operations. Select the most effective chemical reagent to desulfurize Stelco’s gas emissions as a strategy to minimize the environmental impact of acid rain in eastern Canada and why? ...
*November 18, 2007*

**Chemistry - DrBob222**

Alright. Thank you so much for the help today.
*November 11, 2007*

**Chemistry - DrBob222**

About these: NaCl + Zn No reaction CaCl2 + NaOH No reaction CaCl2 + Zn No reaction CaCl2 + Na2SO4 No reaction How would these give no reaction. NaCl + Zn ==> ZnCl + Na CaCl2 + NaOH ==> Ca(OH)2 + NaCl CaCl2 + Zn ==> ZnCl + Ca CaCl2 + Na2SO4 ==> CaSO4 + Na
*November 11, 2007*

**Chemistry - DrBob222**

Wait, AgNO3 with any unknown with Cl present would form a precipatate. So I can use that to tell between HNO3 and HCl. So now is the whole thing correct?
*November 11, 2007*

**Chemistry - DrBob222**

Alright, I've made a list of reactions that would produce precipatations. NaCl + Zn CaCl2 + NaOH CaCl2 + Zn CaCl2 + Na2SO4 CuSO4 + NaOH CuSO4 + Zn NaOH + AgNO3 NaOH + Zn BaOH2 + AgNO3 BaOH2 + Zn BaOH2 + Na2SO4 So this way I can figure if it is NaCl, CaCl2, CuSO4, NaOH,Ba(...
*November 11, 2007*

**Chemistry**

I posted before about designing a procedure to determine two unknowns (1 solid, 1 solution). The possible solutions were: NaCl, CaCl2, CuSO4, NaOH,Ba(OH)2, HCl, HNO3, or H2O. The reagents given are: NaOH, HCl, AgNO3, Zn metal, Na2SO4, and H2O. The procedure I've designed ...
*November 11, 2007*

**Calculus**

f(x) = x(x^2 + 1)^(1/2) f'(x) = (x)(1/2)(x^2+1)^(-1/2)(2x) + (1)(x^2+1)^(1/2) f'(x) = (x^2)(x^2+1)^(-1/2) + (x^2+1)^(1/2)
*November 11, 2007*

**Chemistry**

Oh thanks. But can you tell me what this means "quantify the amount of solute in the solution".
*November 11, 2007*

**Chemistry**

I have to do lab experiment where I design a procedure to determine the identity of two unknowns given to me. One will be a solid and one will be a solution. I also have to quantify the amount of solute in the solution. The possible solids it could be are NaCl, KNO3, KHP, Zn, ...
*November 11, 2007*

**math**

This is probably really easy to work out: x^2=(x-2)(x+3) ^meaning to the power of I've got to: x^2=x^2+x-6 Don't know what to do next
*October 31, 2007*

**math**

Solve the following equations giving any roots in terms of pi in the .......? interval -2pi ≤ 0 ≤ 2pi. a) 2cos²Θ + sin²Θ = 0 b) 2cos²Θ + sin²Θ = 1 c) 2cos²Θ + sin²Θ = 2
*October 29, 2007*

**Chemistry**

Copper dissolves in nitric acid, producing copper (ll) nitrate. After reaction with sodium hydroxide and heating, copper nitrate changes to copper (ll) oxide. Calculate the percent yield of this process if 1.235 g of copper produced 1.452 g of copper oxide.
*October 28, 2007*

**Physics**

Mars' moon Phobos has a mass of 1.07x1016 kg and a mean radius of 11.1 km. Let's say our rocket blasts off from the surface of Phobos when Phobos is 9500 km from the surface of Mars. Does the rocket have to work harder to escape from the gravitational pull of Phobos or...
*October 21, 2007*

**science**

to find the vertical velocity we use 40*cos(30)=34.6 m/s W= KE = 1/2 mv^2 =1/2*0.15*34.6^2= 89.797 J or 90 J
*October 21, 2007*