# Posts by Rachel

Total # Posts: 1,553

**Calculus**

Find the integral of x/ (x^4+x^2+1) from 2 to 3. I was going to integrate using the method for partial fractions but I can't factor x^4+x^2+1.

**Calculus**

What is the integral of 1-tan^2theta from 0 to pi/3? Using the identity tan^2theta=sec^2theta-1, I got my answer to be 2pi/3 - sqrt*3 Can someone verify this for me please?

**Chem- Dr. Bob!**

Oh! Okay, I'm familiar with R groups on amino acids etc.. The question just asks me to label the hybridization for each carbon and oxygen atom. So here's what I've got: The carbon atoms bonded to eachother are sp2 hybridized atoms. The carbon atoms bonded double ...

**Chem- Dr. Bob!**

Posted by Rachel on Thursday, January 20, 2011 at 3:57pm. Does anyone know where I can get an image of the valence bond model for maleic acid? ie. showing the pi and sigma bonds and indicating the hybridization (sp2, sp3.. ) OR could someone describe these things to me? I'...

**Chemistry**

Can someone please check my work? Calculate the mass of (NH4)2S2O8 needed to prepare 250mL of a 0.100M solution. I got 5.705 g. Calculate the volume of 2.00M KI needed to prepare 250mL of a 0.200M solution. I got 0.025L or 25mL. Calculate the volume of 0.100M Na2S2O3 needed to...

**Chemistry**

Does anyone know where I can get an image of the valence bond model for maleic acid? ie. showing the pi and sigma bonds and indicating the hybridization (sp2, sp3.. ) OR could someone describe these things to me? I'm just trying to check my work and make sure I didn't ...

**statistics**

Ordinal. Data is classified into two types: qualitative (aka categorial) or quantitative. Within the qualitative types, there are ordinal (which is ordered data- common ex. is sm, md, lrg- just as in your question) or non-ordinal.

**geometry**

How can I prove that triangle jlm is congruent to triangle ljk if line jl is perpendicular to line lm and line lj is perpendicular to line jk and line mj is congruent to line kl

**English**

It was impossible for him to come. What part of speech is "impossible" in the previous sentence?

**English**

In the sentence "He was made clean." what part of speech is clean?

**math**

528

**math**

The answer is 18,444

**Algebra-Please help**

so the answer is x = 6 according to what you're saying? and the domain is the (h) in here correct? So in the future I just look for the h , take the opposite and that is my domain?

**Algebra-Please help**

Where do I look for the domain in this- The domain of y =1/(x-6) + 3 Possible answers: All real numbers except x=6 All real numbers except x = -6 All real numbers except x=3 All real numbers except x= -3 Thank you

**Algebra**

Is there an easier way to do this? "A freight train leaves a station at 4:00 p.m. traveling at 30 kilometers per hour. A passenger train leaves 1 hour later, traveling at 50 kilometers per hour. At what time will the passenger train overtake the freight train?

**5th grade math**

3/6 - 2/6 = 1/6

**Physics**

Consider a version of the atwood machine in which the masses are frictionless incline. The mass sliding on incline 1, m1, is 1.5 kg, and the angle of this incline is 62 deg. If the mass on the second incline, m2, is 2.5 kg, what is the angle 2 so that the system does not ...

**math**

how to make 29 9ths a mixed number

**English**

with my irl

**Physics**

Describe how an electroscope works?

**biology**

I don't know myself. I am asking the same question.

**algebra 2**

The length of a rectangle is 5 less than 3 times the width. If the perimeter is 54 units, what is the length and the width?

**algebra**

combine and reduce 6b/3a + b/a = answer 3b/a

**mrs. sue please read (History)**

What about for single parents?

**History quick question**

Did people back in the 1700's use financial aid/assistance.?

**huckleberry finn**

thrashed (25) cowhiding (25) licked (26) skinned stonned tanned I do not know the page numbers for the last 3

**Chemistry**

Explain why CH2ClBr and CH2Cl2 do not have optical, geometric, or structural isomers?

**physics**

how many lunar radii are in one AU?

**More Frequency - Physics**

A guitar player plucks two strings simultaneously. One string is tuned to a (fundamental) frequency of 381 Hz. It is found that beats are audible, with a beat frequency of 5.54 Hz. What are possible values for the frequency of the other string? (Answer the larger frequency ...

**Frequency - Physics**

An organ pipe that is closed at one end has a fundamental frequency of 128 Hz. There is a leak in the church roof, and some water gets into the bottom of the pipe, as shown in the Figure. The organist then finds that this organ pipe has a frequency of 217 Hz. What is the depth...

**math**

Ms. Gutierrez needs to order rope for her gym class of 32 students. Each student will receive a piece of rope that is 5 feet 8 inches long. What is the total length of rope Ms. Gutierrez needs to order for her class?

**Math**

Rationalize the denominator. Assume all variables represent positive numbers? - 245x3 y5

**physics**

How much work must be done to stop a 1040 kg car traveling at 111 km/h?

**Algebra**

Show that two WRONG's can make a RIGHT. Replace each different letter in the addition problem with a different digit. It is required that O=zero.

**Chemistry**

Cobalt-60 is a radioactive isotope used to treat cancers. A gamma ray emitted by this isotope has an energy of 1.33 MeV (million electron volts; 1 eV = 1.602 multiplied by 10-19 J). What is the frequency (in Hz) and the wavelength (in m) of this gamma ray?

**algebra 2**

can you answer this question? a store is offering a discount of 30% on a suit. There is a sales tax of 6%. A) using a composition of function, represent this situatio in which the discount is taken before the sales tax is applied. B) using a composition of functions represent ...

**sociology**

Ok thank you so much for the help!! This is how I described the difference between them. Deviance-In a sociological context describes actions or behaviors that violate cultural norms including formally-enacted rules as well as informal violations of social norms. It is the ...

**sociology**

What is the difference between deviance and nonconformity?

**math**

not sure!

**math**

solve for x: 2xcubed+18x=-15xsquared

**chemistry**

For each of the following acid-base reactions, calculate how many grams of each acid are necessary to completely react with and neutralize 2.1g of the base. 1) HCl(aq)+NaOH(aq)-->H2O(l)+NaCl(aq) 2) 2HNO3(aq)+Ca(OH)2(aq)-->2H20(l)+Ca(NO3)2(aq) 3) H2SO4(aq)+2KOH(aq)-->...

**chemistry**

Determine the theoretical yield of C when each of the following amounts of A and B are allowed to react in the generic reaction: A+2B-->3C 1) 1mol A; 1 mole B 2) 1mole A; 3 mole B 3) 2mole A; 2 mole B 4) 32mole A; 68 mole B

**chemistry**

the value for the Ksp of silver chromate is reported to be 1.1 x 10^-12. in a saturated solution of silver chromate, the silver ion concentration is found to be 2.5 x 10^-4M. what must the chromate ion concentration be?

**Geometry**

A farmer uses 140 ft. of fencing to enclose a rectangular field. if the ratio of length to width is 3:4, find the diagonal of the field. Any help is appreciated, thank you!

**French**

Can you check these thanks. Le métro Directions: Completez 1. Il y a dix tickets de métr dans un ----------. Answer: carnet 2. On peut acheter des tickets au ----------- ou au -------------. Answer 1: guichet Answer 2: distribueur automatique 3. Les voyageurs ...

**chem**

How do I figure out the final Fe?

**chem**

A 455-g chunk of iron is removed from an oven and plunged into 385g water in an insulated container. The temperature of the water increases from 27 degrees celsius to 89 degrees celsius. If the specific heat of iron is 0.449 J g^-1 degrees Celsius^-1, what must have been the ...

**chemistry**

How many calories does it take to convert 22 grams of liquid water with a temperature of 48 degrees C to steam?

**science**

I mean Is 2Ag+S the same as Ag2S? The 2nd 2 is supposedly a subscript

**science**

Is 2Ag+S the same as Ag©üS?

**Statistics**

IQ test scores are normally distributed with a mean of 97 and a standard deviation of 11.An individual's IQ score is found to be 123.Find the z-score corresponding to this value

**physics**

81.7kg

**physics**

thanks

**physics**

What force is required to accelerate a 90kg bike to 20 m/s in 15 sec? I need to know HOW to do it!

**physics**

What force is required to accelerate a 90kg bike to 20 m/s in 15 sec? I need to know HOW to do it!

**global**

if you are a greek individual living under ottoman rule, what would you say to persuade a European nation to help your cause ?

**physics**

A 625-kg racing car completes one lap in 14.3 s around a circular track with a radius of 55.0 m. The car moves at constant speed. (a) What is the acceleration of the car?

**physics**

Two force vectors F1 = (2.5 N) x - (3.0 N) y and F2 = - (6.0 N) x + (4.8 N) y are applied to a particle. What third force F3 would make the net, or resultant, force on the particle zero? Magnitude ___ N Direction ___° (from the +x axis)

**physics**

Two force vectors F1 = (2.5 N) x - (3.0 N) y and F2 = - (6.0 N) x + (4.8 N) y are applied to a particle. What third force F3 would make the net, or resultant, force on the particle zero? Magnitude ___ N Direction ___° (from the +x axis)

**chemistry**

write a net ionic equation for the following: 1)Iron (III) chloride reacts with Potassium hydroxide to produce Iron (III) oxide, Potassium chloride, and Hydrogen gas. 2)Hydrochloric acid reacts with Potassium carbonate to produce Potassium chloride, Hydrogen gas and Carbon ...

**chemistry**

write a net ionic equation for the following: Copper (II) sulfate reacts with Ammonium hydroxide to produce Copper (II) oxide, Ammonium sulfate, and water.

**Phsyics**

A bullet of mass 1.8 X 10-3 kg is moving at +500. m/s when it impacts a tree stump. It penetrates into the stump 6.00 centimeters before coming to rest. 1. Assuming the acceleration to be constant, calculate the force (including direction) exerted by the stump on the bullet.

**Phsyics**

A bullet of mass 1.8 X 10-3 kg is moving at +500. m/s when it impacts a tree stump. It penetrates into the stump 6.00 centimeters before coming to rest. 1. Assuming the acceleration to be constant, calculate the force (including direction) exerted by the stump on the bullet.

**Phsyics**

A bullet of mass 1.8 X 10-3 kg is moving at +500. m/s when it impacts a tree stump. It penetrates into the stump 6.00 centimeters before coming to rest. 1. Assuming the acceleration to be constant, calculate the force (including direction) exerted by the stump on the bullet.

**chemistry**

A pure copper cube has an edge length of 2.00cm. How many copper atoms does it contain? (volume of a cube = (edge length)^3; density of copper = 8.96g/cm^3 )

**chemistry**

thank you so much. you explain things really well!

**chemistry**

Lead is often found in Earth's crust as several lead compounds. Calculate the mass in kilograms of the amount of each of the following lead compounds that contains 4500kg of lead. 1)PbCO3 (cerussite) 2) PbSO4(anglesite)

**chemistry**

What volume of each of the following solutions contains 0.13mol of KCl? 1).345M of KCl 2)2.0M of KCl 3).895M of KCl

**chemistry**

How many liters of a 0.530M sucrose (C12H22O11) solution contain 1.3kg of sucrose?

**chemistry**

A chemist wants to make 3.1L of a 0.104M solution. How much KCl in grams should the chemist use?

**french**

Could you check these thanks. Directions: Répondez en utilisant un pronom (en). 1. Il y a combien de chambres dans cet hôtel? (cent) Answer: Il y en a cent. 2. Il y a combien de lits dans chaque chambre? (deux) Answer: Il y en a deux 3. Il y a combien de placards ...

**calculus**

find the points on the graph of y=secx where the tangent is parrallel to 6y-4x=8. (0 is less than or equal to x and x is less than or equal to 2pi). Use exact values.

**math**

A ball is thrown upward from a height of 100 ft. with an initial velocity of 80 ft/sec. Find the function.

**Persuasive Topic help**

For my speech class we need to make a speech on a persuasive topic that will be interesting and fun to hear. It needs to be a topic that no one ever really talks about, or something that no one really knows about. For example pregnancy is something we already know. Can you ...

**french**

Can you check these thanks. Part 1 Directions: Répondez selon le modèle. Elle va souvent à Montréal? Oui, elle y va souvent. (As you can see we are now learning the pronoun y) 1. Ils vont souvent à Paris? Answer: Oui, ils y vont souvent. 2. ...

**Chemistry**

I am required to design an experiment which will allow me to produce exactly 12.5g of pure dry Copper Hydroxide. I need to include equipment required, Chemicals required, step by step method and any particular limitations/cautions which must be exercised whilst following the ...

**SraJMcGin**

Correction: I don't know when I'm supposed to add an extra e or ees. Can you give me examples. Thanks so much

**SraJMcGin**

Can you help me with the passé composé: être and avoir. I understand when to use être and avoir but I don't know if I'm supposed to add an extra e or ees for the verbs.

**french**

Can you check these also thanks. Directions: Récrivez les phrases au passé composé. Le passé composé: être ou avoir. 1. Marie monte au troisième étage. Answer: Marie est monté au troisimème êtage. 2. ...

**french**

Can you check these it's based on Le passé composé: être ou avoir. Directions: Complétez au passé composé Les deux copines -----1------ (sortir) de la maison à neuf heures. Elles ------2------ (sortir) tous leurs bagages. ...

**6th grade**

Look up the word "culture."

**economics**

qs=-400+2p qd=1600-2p how do i graph that

**science**

is a rock a compound, element, or solid?

**Gen Chem 1**

A tanker truck carrying 2.01×10^3kg of concentrated sulfuric acid solution tips over and spills its load. The sulfuic acid is 95.0% H2SO4 by mass and has a density of 1.84g/L. Sodium Carbonate (Na2CO3)is used to neutralize the the sulfuric acid spill. How many kilograms ...

**French (need a website link quick question)**

I need a website link that will give me a practice test to Qu'est-ce qui and Qu'est-ce que. Where Qu'est-ce qui acts as a subject and Qu'est-ce que acts as an object. I also need a test on negative and affirmative commands. For example: Montrez-moi-la radio ...

**Linear Equations**

Can you check these thanks. Linear Equations Directions: Write each equation in standard form. 1. y=7x-5 Answer: 7x-y=5 2. y=3/8+5 (3/8 is a fraction) Answer: 3x-8y=40 3. x= -2/7y+3/4 Answer: x+14y=12 4. 3y-5=0 Answer: x+3y=0 Find the x-intercept and y-intercept of the graph ...

**Literature**

Can I get your opinion on the story Sinner's in the Hands of An Angry God. What would be your personal response of this story. (I just need an idea)

**Literature question**

Can you give me a summary to the story Sinners in the Hands of an Angry God? Thanks. By the way if you do give me a link please don't give me a google link because for some reason my computer doesn't want to pull up google's homepage. Thanks.

**physic**

how to caluate a ke vs. time graph

**college physics**

A freight train has a mass of 1.7 multiplied by 107 kg. If the locomotive can exert a constant pull of 7.4 multiplied by 105 N, how long does it take to increase the speed of the train from rest to 68 km/h?

**Chemistry**

The pressure of 6.0 L of an ideal gas in a flexible container is decreased to one-eighth of its original pressure, and its absolute temperature is decreased to one-seventh of the original. What is the final volume of the gas?

**ECONOMICS**

qs=-400+2p qd=1600-2p how do i graph that

**Physics**

First you need to solve for time by using d=(1/2)(a)(t^2)+(vi)t 1m=(1/2)(9.8)t^2 vertical initial velocity is 0m/s t=.45 sec Then you find the horizontal distance traveled by using v=d/t 1.3m/s=d/.54sec d=.585m Then you need to find the time of player B by using d=(1/2)(a)(t^2...

**calc 3**

Find the limit ( e^-3t i + tsin(1/t)j + arctan tk ) if it exists. If not say doesn’t exsist. (t→ ∞)

**Math 117**

length = x width = x-l area = length*width 12 = (x)*(x-1) solve for x... use the equations above to get the length and width..

**calculus**

f(x)=kx^2+3 a) if the tangent lines to the graph of f at (t,f(t)) and (-t, f(-t)) are perpendicular, find t in terms of k b) Find the coordinate of the point of intersection of the tangent lines mentioned in part (a) in terms of k

**Science**

A passenger in a moving train drops an apple. Describe how a man standing by the train tracks sees the apple falling when he looks through the window.

**math 115**

f(-4)=4-2(-4) f(-4)=4+8 f(-4)=12 you must be bored of me by now..haha!

**math/115**

you're welcome again.. =)

**math/115**

solve the second one by substituting x with -3...