Monday

March 2, 2015

March 2, 2015

Total # Posts: 1,531

**Chemistry**

If water I'd added to magnesium nitride, ammonia gas is produced when the mixture is heated Mg3N2 (s) + 3H2O (l) ----> 3MgO) (s) + 2NH) (g) *Only the numbers at the beginning aren't subscripts* If 10.3 g of magnesium nitride is treated with water, what volume of ...
*January 19, 2011*

**Chemistry**

Determine the pressure in a 125-L tank containing 56.2 kg of oxygen gas at 25 °C. So, PV=nRT I convert 25 °C to 298.15 K Do I have to convert anything else? What else do I do?
*January 19, 2011*

**Chemistry Lab**

1.312E03
*January 17, 2011*

**Combinatorics**

In how many ways can 8 students be assigned to 2 groups if each group must have at least 3 students?
*January 17, 2011*

**Ochem**

For the reaction between chloroacetic acid and 4-chlorophenolate to synthesize 4-chlorophenoxyacetic acid, why is this reaction a sn2 reaction?
*January 15, 2011*

**trigonometry**

can you explain to me in details please of how these type of questions can be answered without using a calculator to find the direct answer. Find the following functions correct to five decimal places: a. sin 22degrees 43' b. cos 44degrees 56' C. sin 79degrees 23'...
*January 13, 2011*

**trigonometry**

sinA= 3/5 and C=17 Finding a and b
*January 12, 2011*

**trigonometry**

sinA= 3/5 and C=17 Finding a and b Their two triangles and i have to find the ratio i just can’t seem to set up the problem right but i gave an example of one of the practice exercise that dealt with finding only (a) so i got confused with finding a and b in that question...
*January 12, 2011*

**trigonometry.**

b= sqrt 17^2 - 10.2^2 = 13.6 ??
*January 10, 2011*

**trigonometry.**

sinA= 3/5 and C=17 Finding a and b would this work as an answer ..? sinA = opp/hyp = a/c = 3/5 = 3*3.4/5*3.4 = 10.2/17 a = 10.2 Applying Pythagoream Theorem a^2 + b^2 = c^2
*January 10, 2011*

**trigonometry.**

In a right triangle sinA= 3/5 and C=17. Find a and b. Be sure to draw a right triangle and letter it properly. how can i solve the math in this problem. i know i would have to use the Pythagoream Theorem but i dont know how to set the problem up first.
*January 10, 2011*

**Physics**

Does the frequency of light change as it enters a different substance? I know that the speed changes. The question might seem easy, but I have contradicting notes, so I'm confused.
*January 6, 2011*

**Trigonometry**

``(please show the steps to how the problems were solved) Using exact values, find the value of: A.12sin 30 degree - 6 tan 45 degree + sec 45 degrees/ 52 B.Sin2A + tan3A/2 - cos A + sec(a+ 15), when A=30degrees
*January 6, 2011*

**Trigonometry**

I need to show my work so i cant use a calculater . did i show it correctly?
*January 1, 2011*

**Trigonometry**

Please review and tell me if i did something wrong. Find the following functions correct to five decimal places: a. sin 22degrees 43' b. cos 44degrees 56' c. sin 49degrees 17' d. tan 11degrees 37' e. sin 79degrees 23'30' f. cot 19degrees 0' 25'...
*January 1, 2011*

**re post Trigonometry**

hopefully this will post more clearly! 12sin 30 degree - 6 tan 45 degree + sec 45 degrees/ 52 = 12¡¤1/2 -6¡¤ 1 + ¡Ì2/52 = ¡Ì2/52 Sin2A + tan3A/2 - cos A + sec(a+ 15)= ¡Ì3/2 + 1 - ¡Ì3/2 + ¡&...
*January 1, 2011*

**Trigonometry**

Using exact values, find the value of: a. 12 sin 30 degrees ¨C 6 tan 45degrees + sec 45degrees / 52 12-1/2-6*(1) + ¡Ì2/52=¡Ì2/52 12-1/2-6+¡Ì2/52 what should i do next?? b. Sin2A + tan3A/2 - cos A + sec(a+ 15) Sin2A + tan3A/2 - cos A...
*January 1, 2011*

**Calculus**

As a baseball player runs from second to third base, he is going 20 feet per second. What is the rate of change from the runner to home when he is halfway to third base? (The sides of a baseball field are 90 feet)
*December 31, 2010*

**Calculus**

At a certain point in time, a cubical crystal has edges 5 mm in length, and these edges are growing at a rate of 2 mm per hour. How fast is the volume increasing?
*December 31, 2010*

**Trigonometry**

tan45+sin60=(sin30+cos30) 1+ã3/2=(1/2+ã3/2) How do i work it from her?
*December 31, 2010*

**trigonometry**

tan^2 30 sqrt(3)/3 To the second power how can i do that ??
*December 30, 2010*

**trigonometry**

tan60=2 tan30/1-tan^2 30 sqrt(3)=I'm confused of that 2 but i guess it means to multiply. again.. sqrt(3)= (2) sqrt(3)/3 / 1- sqrt(3)/2 ^2 now i dont know how to square tan . if u can show me in details i would appreciate it. this is just a practice problem and i want to ...
*December 30, 2010*

**French**

Hi, I'm wondering if any of you could lead me to the mark scheme for the IGCSE French Reading and Directed Writing Paper 23 May/June 2010? Any help would be appreciated. Thank you.
*December 21, 2010*

**Math**

By solving the equation x/8 + x/10 = 90. Sorry for the late response.
*December 17, 2010*

**Math**

In jar 1, 1/8 of the marbles are white. In jar 2, 1/10 of the marbles are white. Since the jars are filled with an equal amount of marbles, take this value to be x. Therefore, x/8 + x/10 should equal to 90, the total number of white marbles. From this, we get x = 400 marbles ...
*December 17, 2010*

**Physics**

It's from a textbook, the answer I'm supposed to get is 5250 Joules..
*December 17, 2010*

**Physics**

A bungee jumper of mass 60 kg jumps from a bridge tied to an elastic rope which becomes taut after he falls 10 m. Consider the jumper when he has fallen another 10 m and is travelling at 15 m/s. Work out how much energy is stored in the rope. Take g=10 m/s^2 and ignore air ...
*December 17, 2010*

**Physics**

At t = 0, a 785 g mass at rest on the end of a horizontal spring (k = 125 N/m) is struck by a hammer, which gives the mass an initial speed of 2.70 m/s. (a) Determine the period of the motion. T= .4979201367s Determine the frequency of the motion. f= 2.008354 Hz (b) Determine ...
*December 7, 2010*

**Math**

There are 4 black marbles and 5 red marbles in a bag. If you reach in and randomly select 2 marbles, what is the probability that both are red? Explain your reasoning.
*December 3, 2010*

**6th grade**

12% is the same thing as .12 So .12*(number of sixth graders) = 24 number of sixth graders = 24/.12 = 200
*December 1, 2010*

**chem**

what is the name of ONO and what is its charge
*December 1, 2010*

**chemistry**

complete and balance the following equation: CoCl*6H2O+ NH4Cl+ NH3+ H2O ---> [Co(NH3)5Cl]Cl2+ H2O
*December 1, 2010*

**chem**

you used a pencil to mark the chromatography paper since the carbon in the "lead" pencil does not dissolve in the solute. why does carbon not dissolve? what type of pen (ink) will also not produce a chromatogram when water is used as the solovent? explain using ...
*November 29, 2010*

**chem**

the total pressure of n2o4 and no2 IS 1.38 atm. if kp is 6.75(25 C) calculate partial pressure of NO2 in the mixture. 2NO2<---> n2o4
*November 28, 2010*

**C++**

I have no idea how to construct this program. Any help is appreciated. Thank you. In a population, the birth rate is the percentage increase of the population due to births and the death rate is the percentage decrease of the population due to deaths. Write a program that ...
*November 17, 2010*

**physics**

An undersea research chamber is spherical with an external diameter of 3.70 m. The mass of the chamber, when occupied, is 26000 kg. It is anchored to the sea bottom by a cable. What is the tension in the cable?
*November 16, 2010*

**Chemistry**

lawls
*November 14, 2010*

**Chemistry**

tony is stupid
*November 14, 2010*

**Earth CRYience**

Assume a parcel of air on the surface with a temperature of 29 degrees Celsius with a relative humidity of 50%. If the parcel rises at what altitude should clouds form?
*November 12, 2010*

**math**

no typo. I tried the quadratic equation and got -.986 and 1.24. Does this mean there are no real roots (an option in the question). Also, for the question 4x^2-12x+9, is the real root (2x-3)?
*November 12, 2010*

**math**

What are the real roots of the quadratic function 4x^2-x+5?
*November 12, 2010*

**4th grade**

Let n= a number n-5
*November 11, 2010*

**3rd grade**

Eleven and five. 11+5=16 11-5=6
*November 11, 2010*

**algebra**

Distribute. 40x-16=84 Add 16 to both sides. 40x=100 Divide both sides by 40. x=2.5
*November 11, 2010*

**English**

Thank you.
*November 11, 2010*

**English**

Complete the sentence by writing the correct form of the word in parentheses. You may not need to change the form that is given. 1. She made her fortune in the ____ market before she became a full-time philanthropist. (security) Would the correct answer be "securities&...
*November 11, 2010*

**MAT 116**

You are on the right track. Be sure to use the order of operations (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction). Multiply the 8 and 15 to get 120, then multiply the 6 and 3 to get 18. That leaves 120-18, which you would simply subtract to get your ...
*November 11, 2010*

**calculus**

Alright. a. y1+y2 should be set up as follows: (x^2+3x-1)+(x-5), which equates to x^2+4x-6 You just combine the like terms. b. (x^2+3x-1)-(x-5) For this one you need to distribute the negative, to get x^2+3x-1-x+5, then combine like terms. c. (x-5)(x^2+3x-1)= x^3+3x^2-x-5x^2-...
*November 11, 2010*

**Earth Science**

what is the dewpoint temperature of a kilogram of air when a psychrometer measures an 8 degree Celsius dry-bulb temperature and a 6 degree Celsius wet-bulb reading?
*November 11, 2010*

**C++**

Write a statement that passes the value 4 to the function below and assign it's return value to the variable result. Thank You. int cube(int num) { return num*num*num; }
*November 11, 2010*

**Statistics**

My apologies, the figure got messed up Paper shredders --------------- 75 115 118 287 250 300 50 Calculators -------------- 110 140 165 90 230 97 269
*November 10, 2010*

**Statistics**

The figures below represent the prices (in dollars) for both paper shredders and calculators. At the 0.10 level of significance, can it be concluded that the variance in price differs between the two types of machines? Paper shredders | Calculators...
*November 10, 2010*

**Earth Science**

What are the effects radiation has on the heating of land and water? Thank You.
*November 4, 2010*

**Earth Science**

What are the primary heat absorbing gases in the atmosphere? What wavelength of radiation do they absorb?
*November 4, 2010*

**chemistry**

what is the reaction equation when maleic anhydride is combines with granular zinc and HCl propose structures for the products you would obtain by treating fumaric acid, cinnamic acid, and butynedioic acid with zinc and HCl. write balanced equations for the reactions.
*October 30, 2010*

**Earth Science**

What are the minimum and maximum durations of daylight at a latitude of 39 degrees north? Thanks.
*October 30, 2010*

**Earth Science**

What causes the intensity and duration of solar radiation received at any place to vary throughout the year?
*October 30, 2010*

**chemistry**

AgI (aq) + NH3 (aq) -->
*October 28, 2010*

**chemistry**

how can AgCl(s) be dissolved completely? write an equation for the reaction
*October 25, 2010*

**Statistics**

find the 90% confidence interval for the variance and standard deviation of a sample of 16 and a standard deviation of 2.1 Assume the variable is normally distributed.
*October 24, 2010*

**Statistics**

Thank you so much!
*October 24, 2010*

**Statistics**

For a sample group of 22, the mean is 86 with a standard deviation of 5. What is the 90% confidence interval of the true mean of the sample? Can you please explain the steps you used to get the answer. Thanks.
*October 24, 2010*

**chemistry**

ok thank you:)
*October 13, 2010*

**chemistry another add on**

c)what is the pH after the addition of 1.0 mL of 0.10 M NaOH to 15 mL of the original solutiom.... i dont really need a im pretty sure my answer is right but should i really be getting the same answer for b and c?
*October 13, 2010*

**chemistry**

b) what is the pH after the addition of 1.0 mL of 0.10 M HCL to 15.00 mL of the solution?
*October 13, 2010*

**chemistry**

what is the pH of a solution prepared by adding 20.00 mL 0f a 0.10 M acetic acid and 10.00 mL of 0.10 M sodium acetate
*October 13, 2010*

**chemistry**

net ionic equations of nitric acid with CO3 2- and with PO4 3-.
*October 13, 2010*

**chemistry**

a titration is done with with 25.00 mL of a .1500 M HBrO solution is titrated with .1025 M NaOH. Ka for HBrO= 2.0 x10^-9. The pH of HBrO before the titration begins is approx. closest to which of the following a. 0.82 b. 4.76 c. 8.70 d 10.60 e. 13.01 the answer is b 4.76 but how?
*October 11, 2010*

**chemistry**

the Ksp for CaF2 is 3.9*10-11. assuming that calcium flouride dissociates completely upon dissolving and that there are no other important equilibria affecting the solubility, calculate the solubility in pure water, of calcium floride in m/L and in g/L
*October 10, 2010*

**physics**

^ That is just an equation, it does not even answer the question.. I don't mean to be rude but even if you know the equation you can't answer the question if you do not know how to apply it.
*September 27, 2010*

**physics (SAT 2)**

just by putting cos(12) in calculator
*September 27, 2010*

**algebra**** 1**

x= 51428571.43 square miles
*September 26, 2010*

**PHyiscs**

A HELICOPTER hovering above a forest fire dumps a large bucket of water. How far does the water fall in the first 3.0 seconds t=3.0s
*September 24, 2010*

**chemistry**

In the movie "The Raiders of the Lost Arc", Indiana Jones and his guide play catch with a gold idol. The idol had a volume of about 1.30 L. In order to determine whether they could really play catch with the idol, calculate the weight (in pounds) of the idol. The ...
*September 13, 2010*

**physics**

Where to get 44.1 for Velocity as in the Centripetal Acceleration?
*September 9, 2010*

**Math(word problems)**

4.Tracie invested $x at 7% and $y at 6%. Write algebraic expressions for: a.the total amount of money invested b.the interest earned at 7% in one year c.the interest earned at 6% in one year d.the total interest earned in one year
*July 28, 2010*

**math**

1.)Explain why ironing boards always remain parallel to the floor and can be adjusted for people of various heights. You may want to consider the following: a.)The legs of the board are built so that AD = BD and DE = DF, and ADF and BDE are straight lines as shown. b.)Which ...
*July 21, 2010*

**Chemistry**

what's #10
*July 12, 2010*

**physics**

A cylindrical space colony 8 km in radius and 60 km long has been proposed as living quarters for future space explorers. Such a habitat would have cities, land and lakes on the inside surface and air and clouds in the center. All this would be held in place by the rotation of...
*June 25, 2010*

**programmning code**

Is this code right? Declare Integer days, counter = 1 Declare Real penny = 1, salary, total = 0 Display "Enter a number of days." Input days Display "Days",TAB,"Salary While counter <= days Set salary = penny/100 Display counter, TAB, salary Set ...
*May 21, 2010*

**Chemistry**

The element niobium has bcc packing with a body-centered cubic unit cell. The volume of the unit cell is 3.59 x 10-26 L. Calculate the density (g/cm3) of the element
*May 12, 2010*

**5th grade**

Hello there Read the problem as it says. Variable "n" raised to the 10th power is equal to 27.
*May 10, 2010*

**Stats**

What is the probability that a simple random sample of 56 special orders will provide an estimate of the population proportion of special orders specifying the color black that is within plus or minus .05 of the actual population proportion,assuming p = .36? In other words, ...
*May 4, 2010*

**physics**

I think you mean third second
*April 18, 2010*

**language**

lol are you posting under several diff names for the same kinda homework?
*April 15, 2010*

**biology**

Replication of the E. coli chromosome takes 40 to 45 minutes, but the organism has a generation time of 26 minutes. How does the cell have time to make complete chromosomes for each daughter cell? For each granddaughter cell? my reponse was that the cells don't fully ...
*March 29, 2010*

**Chemistry**

bump
*March 14, 2010*

**his 135**

This is one of the more helpful posts I found after finding this site on google, and it (like most others) is almost useless in its content related to the 1960's subculture.. and it is also filled with rude people telling its customers to search elsewhere.. I too will take...
*March 11, 2010*

**chemistry**

NS6 P2S6 C? Phosphorus tetrabromide
*March 11, 2010*

**Global Studies**

actually if you state the documents out like that, you LOSE points and wont be able to go in the expanded core. just say "so and so stated this" and then in parentheses, say the document number. believe me ive been doing this without knowing, and my ap teacher just ...
*March 6, 2010*

**Chemistry *URGENT***

URGENT help! 3. A rock sample was dated using potassium-40, Neasyrenebt ubducated tgat 1/8 of the original parent isotope is left in the rock sample. How old is the rock? 5. When a sample of lava solidfied, it contained 28g of uranium-238. It that lava sample was later found ...
*March 5, 2010*

**Social Studies**

How does a town's economic base determine how the community takes shape? Please help me.
*March 4, 2010*

**chemistry**

the answer you did last night was wrong. sorry DrBOb :{
*February 21, 2010*

**chemistry**

your all idiots!!! both .09505 and 3.3 are wrong were doing it in a computer program and we reworked the problem!!!
*February 20, 2010*

**biology**

oh come on, this is the easiest thing i have ever heard. google much?
*February 15, 2010*

**Chemistry**

What volume ( L ) of the solute HCO2H should be combined with 5480 mL of the solvent H2O to make a solution that is 0.443 m HCO2H.
*February 2, 2010*

**Chemistry**

Calculate the mass ( kg ) of the solute C4H8O and the volume ( mL ) of the solvent C6H6 that should be combined to generate 6450 g of a solution that is 2.07 m C4H8O. Density (kg/l) C4H8O 0.8892 C6H6 0.8786
*February 1, 2010*

**Physics**

Im doing this question right now and I cant understand it! how did you get that value?!
*January 22, 2010*

**Literary Analysis and Composition**

LOL K12 in the house baby
*January 21, 2010*

**chemistry**

i just submitted it and its nf=2 and balmer
*January 15, 2010*

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