# Posts by Hannah

Total # Posts: 3,323

**Halfway solved-calc**

Wow, thank you so much! But I'm wondering where the + 1 for the R and r, comes into play?

*May 22, 2013*

**Halfway solved-calc**

So I'm trying to solve this problem but one thing I don't get is, how do I know which method to use just by looking at the graph (disk, washer, or shell)? Find the volume of the solid generated by revolving the region bounded by the graphs y=x^2- 4x+ 5 and y= 5-x about...

*May 22, 2013*

**Math**

I absolutely understand this now. Thank you so much. I really couldn't have done it without your help Steve.

*May 22, 2013*

**Math**

No there wasn't. This is exactly the problem our substitute gave us, and I was having a hard time figuring out why that was so. Do they not intersect at (2, 0) as well? I was told this answer is incorrect as well (-1/4). I'm perplexed. :S

*May 22, 2013*

**Math**

3) Find the area bounded by the curves f(x)= x^3 + x^2 and g(x)= 2x^2 + 2x. I get 4653pi/105 after help from Mr. Reiny, but this is wrong. Have I calculated incorrectly? Thank you

*May 22, 2013*

**integral calculus**

I'm sorry about that. Can you explain why there is an error Mr. Pursley? I genuinely don't understand how there is an error.

*May 22, 2013*

**integral calculus**

let u=x^2 du= 2x dx dx=du/2x dx=du/2sqrt(u) -1/4 cos u is the integral

*May 22, 2013*

**Calculus**

3) Find the area bounded by the curves f(x)= x^3 + x^2 and g(x)= 2x^2 + 2x. I get 4653pi/105 after help from Mr. Reiny, but this is wrong. Have I calculated incorrectly? Thank you

*May 22, 2013*

**Calculus**

I did it and I get 4653pi/105 but this is wrong. Have I calculated incorrectly?

*May 21, 2013*

**Calculus**

Thank you very much Reiny. I understand it a bit better now.

*May 21, 2013*

**Calculus**

We're learning disks, shells, and cylinders in school but we have a substitute and I've been trying to teach this to myself. Can you check them please? =) Thank you! 1) Find the volume of the solid formed when the region bounded by curves y=x^3 + 1, x= 1, and y=0 is ...

*May 21, 2013*

**Calculus**

We're learning disks, shells, and cylinders in school but we have a substitute and I've been trying to teach this to myself. Can you check them please? =) Thank you! 1) Find the volume of the solid formed when the region bounded by curves y=x^3 + 1, x= 1, and y=0 is ...

*May 21, 2013*

**biology**

ap biology lab -what barriers might hinder the acquisition of plasmids

*May 17, 2013*

**bio**

I am doing the biology ap bacteria DNA transformation lab and I came up with a transformation efficiency of 150,000. I read somewhere that they should be between 2,000-8,000. is my answer way off? My group counted an average of 1529 colonies to begin with so i don't see ...

*May 17, 2013*

**geometry**

AB= ft2 CB = ft l (slant height) = ft S = ft2 I need to find the answers this is a cone with a radius of 5 and a height of 13. Thank you

*May 16, 2013*

**math**

I need to find the A small b, C small b, slant height, and surface area of a cone. The height is 9.2 and radius is 5.6. Please help

*May 16, 2013*

**math**

The Transamerica Pyramid in San Francisco is shaped like a square pyramid. It has a slant height of 856.1 feet and each side of its base is 145 feet. Find the lateral area of the building.

*May 16, 2013*

**geometry**

please help

*May 15, 2013*

**geometry**

The Transamerica Pyramid in San Francisco is shaped like a square pyramid. It has a slant height of 856.1 feet and each side of its base is 145 feet. Find the lateral area of the building.

*May 15, 2013*

**geometry**

Find the surface area of a cone with diameter 27 m and slant height 19 m. Leave your answer in terms of pie

*May 15, 2013*

**math**

Find the surface area of a cone with diameter 27 m and slant height 19 m. Leave your answer in terms of . Note: You do not need to include in your answer

*May 15, 2013*

**math**

The Transamerica Pyramid in San Francisco is shaped like a square pyramid. It has a slant height of 856.1 feet and each side of its base is 145 feet

*May 15, 2013*

**gov**

what was the lower courts decision of the terry v.s ohio case?

*May 8, 2013*

**math**

7 inches is across the top of the can and 5 goes up and down.

*May 8, 2013*

**math**

can you pleae explain how to do this?

*May 8, 2013*

**math**

a cylinder can of coca has the dimensions of base 7in and height 5 inches. what is the approximate surface area available for the label?

*May 8, 2013*

**math**

197.8

*May 8, 2013*

**math**

I don't understand how to do this

*May 8, 2013*

**math**

A cylindrical carton of oatmeal with radius of 3.5 in. is 9 in tall. If all surfaces except the top are made of cardboard , how much cardboard is used to make the oatmael carton. Round your answer to the nearest square inch

*May 8, 2013*

**Math story problem**

A satellite dish is shaped like a paraboloid of revolution. the signals that emanate from a satellite strike the surface of the dish and are reflected to a single point, where the receiver is located. If the dish is 14ft across at its opening and 4ft deep at its center, at ...

*May 7, 2013*

**Math!**

Solve the equation on the interval 0<theta<2pi -tan(2theta)+2sin(theta)=0

*May 7, 2013*

**Trig**

cos[(tan^-1(3/4))+(cos^-1(9/41))]

*May 6, 2013*

**math**

I am supposed to find the area of a segment of a circle. The circle is cut with two radi with an angle of 90 degrees. Then where the radi touch the circle another line is drawn to connect them. The triangle and the small section between the triangle and the edge of the circle ...

*May 5, 2013*

**geometry**

possible answers are a 9 pi / 4 - 9 units squared b 6 pi / 4 - 4.5 units squared c 9 pi / 4 units squared d 9 pi /4 - 4.5 units squared

*May 4, 2013*

**geometry**

Find the area of the segment of the circle. Leave your answer in terms of pi. there is a circle with a 90 degree triangle and one side is 3 cm

*May 4, 2013*

**geometry**

You and your friend ordered a 12 cut pizza with a radius of 8 inches. How much cheese is needed to cover one slice of the pizza? Hint: Find the area of one slice. Round your answer to the nearest tenth

*May 4, 2013*

**math**

If a ramp has a slope of 1/8, and I need to put a support post 11 feet from the low point on the ramp, how long should the post be?

*April 29, 2013*

**Calculus**

Nevermind you can ignore this, I figured it out. I was just forgetting to do e^answer at the end.

*April 25, 2013*

**Calculus**

Find the limit as x approaches infinity of (lnx)^(1/x). This unit is on L'Hopital's rule. I know that the answer is 1, I just don't know how to get there. I tried taking the ln of everything so that you have ln(the whole limit) = limx-->infinity (1/x)ln(lnx) but...

*April 25, 2013*

**physics**

In a series circuit, the voltage across the resistor has an amplitude of 10 V. Across the inductor it is 25 V and across the capacitor it is 9 V. To the nearest tenth, what is the amplitude of the voltage across the whole group?

*April 22, 2013*

**Algebra (logs)**

Log3 15

*April 22, 2013*

**Economics**

Would leisure time considered an inferior good when the substitution effect dominates? I think that the answer is yes because if you are willing to work more hours in order to make more money than you do not value leisure time that much. Is this correct? Thank you

*April 22, 2013*

**Microeconomics**

Is leisure time considered an inferior good when the substitution effect dominates? I think that the answer is yes because if you are willing to work more hours in order to make more money than you do not value leisure time that much. Is this correct? Thank you!

*April 21, 2013*

**Algebra**

Find the specified value of the following functions and state the domain of each one. f(x)=x-11;g(x)=7x^2 (a) (f+g)(5)=

*April 19, 2013*

**Economics(Please check, thank you)**

Is leisure time considered an inferior good when the substitution effect dominates? I think that the answer is yes because if you are willing to work more hours in order to make more money than you do not value leisure time that much. Is this correct? Thank you!

*April 19, 2013*

**Data Management**

How many 4 digit number can be made using 0 -7 with no repeated digits allowed?

*April 16, 2013*

**Data Management**

A bag contains three green Christmas ornaments and four gold ornaments. If you randomly pick two ornaments from the bag, at the same time, what is the probability that both ornaments will be gold?

*April 16, 2013*

**Data Management**

How many ways can the manager of a baseball team put together a batting order of his nine players, if the shortstop must bat 3rd?

*April 16, 2013*

**physics**

Suppose the Sun is 1.52669 × 108 km from Earth. The speed of light is 2.99792 × 108 m/s. How long does it take for its light to reach us? Answer in units of min

*April 8, 2013*

**chem**

A certain constant-pressure reaction is nonspontaneous at 37°C. The entropy change for the reaction is 83 J/K. What can you conclude about the sign of ÄH? What can you conclude about the magnitude of ÄH?

*April 6, 2013*

**chem**

Express the second law of thermodynamics as a mathematical equation. (Select all that apply.) For a reversible process, ÄSuniverse = 0. For a spontaneous process, ÄSuniverse > 0. For a spontaneous process, ÄSuniverse = 0. For a reversible process, Ä...

*April 3, 2013*

**chem**

the volume of 0.220 mol of an ideal gas at 34°C is increased isothermally from an initial volume of 12.0 L. If the final volume is 21.5 L, calculate the entropy change for the process.

*April 2, 2013*

**Math**

Which is the best estimate of -15/16 divided (-1/2)?

*April 1, 2013*

**biology**

how do chromosomes move inside a cell during each stage of cell division?

*March 31, 2013*

**chem**

Which of the following could be added to a solution of sodium acetate to produce a buffer? ? A) acetic acid only B) acetic acid or hydrochloric acid C) potassium acetate only D) sodium chloride or potassium acetate E) hydrochloric acid only i knowt he answer is b but i don'...

*March 31, 2013*

**chem**

how do i do the ^4 when there is an x and it is a bionomial. i am having trouble

*March 28, 2013*

**chem**

In an excess of NH3(aq), Cu2+ ion forms a deep blue complex ion, Cu(NH3)42+, which has a formation constant Kf = 5.6 1011. Calculate the Cu2+ concentration in a solution prepared by adding 4.8 10-3 mol of CuSO4 to 0.500 L of 0.32 M NH3.

*March 28, 2013*

**government**

how did the watergate scandal gain attention? and why was an investigation launched?

*March 28, 2013*

**chemistry**

Calculate the solubility of Mn(OH)2 in grams per liter when buffered at each of the following. (a) pH 7.7 (b) pH 9.6 (c) pH 11.3

*March 27, 2013*

**chem**

The molar solubility of MgF2 at 25°C is 1.2 10-3 mol/L. Calculate Ksp. i got the euqation ksp= [F-]^2[Mg]2+ and plugged in 1.2e-3 and got 1.7e-9 but it is wrong. also this question If 0.0968 g of CaF2 dissolves per liter of solution, calculate the solubility-product ...

*March 26, 2013*

**chem**

Consider the titration of 30.0 mL of 0.050 M NH3 with 0.025 M HCl. Calculate the pH after the following volumes of titrant have been added. (The Kb for NH3 is 1.8e-05.) (a) 0 mL . (b) 25.0 mL . (c) 59.0 mL . (d) 60.0 mL (e) 63.0 mL (f) 67.5 mL

*March 25, 2013*

**government**

I have serrched her name under google but still have not found what i need. what does committee membership mean? isnt she just a senator? and i cant find her party duties

*March 25, 2013*

**government**

I am doing a research paper on senator Debbie Stabenow and I cant find some information. What are her years of experience, committee membership and party duties? also how is she viewed by different special interst groups? thanks!

*March 25, 2013*

**math**

Classify each statement as sometimes, always, or never true. A. 2^(2/3)*4^(4/3)=8*2^(1/3) B. If x>0, then (squareroot x*squareroot 2)^3 =x^(3/2) 2^(3/2) C. If x>0, then (squareroot x+ squareroot 2)^3 =x^(3/2) 2^(3/2) D. The only solution to x^(2/3)= 4 is x=8

*March 24, 2013*

**chem**

Assume that 35.0 mL of a 0.13 M solution of a weak base B that accepts one proton is titrated with a 0.13 M solution of the monoprotic strong acid HX. (a) How many moles of HX have been added at the equivalence point?

*March 24, 2013*

**chem**

i am confused how you got the .0444?

*March 23, 2013*

**chem**

Calculate the pH at the equivalence point in titrating 0.100 M solutions of each of the following with 0.080 M NaOH. chlorous acid (HClO2) benzoic acid (C6H5COOH)

*March 23, 2013*

**AP Physics**

A small block with mass 0.035 kg slides in a vertical circle of radius 0.425 m on the inside of a circular track. During one of the revolutions of the block, when the block is at the bottom of its path, point A, the magnitude of the normal force exerted on the block by the ...

*March 22, 2013*

**physics**

Why is an echo weaker than the original sound? 1. The echo has a shorter wavelength than the original sound due to the reﬂection. 2. The echo has a smaller amplitude than the original sound because sound spreads and its intensity decreases with distance. 3. The echo has...

*March 21, 2013*

**physics**

If the intensity of a person’s voice is 3.6×10−7 W/m2 at a distance of 2.1 m, how much sound power does that person generate? Answer in units of W

*March 21, 2013*

**chem**

How many grams of NH4Cl must be added to 0.560 L of 1.90 M NH3 solution to yield a buffer solution with a pH of 8.50? Assume no volume change. Kb for NH3 = 1.8 10-5. i am confused as how to find the grams?

*March 19, 2013*

**chem**

What CH3COONa concentration is required to prepare a buffer solution with a pH of 4.80 if [CH3COOH] = 0.150 M? Ka of CH3COOH = 1.8 10-5.

*March 19, 2013*

**chemistry**

at the bottom i put a)more acidic? b)less acidic? c)will noit chnage d)less

*March 19, 2013*

**chemistry**

thanks! were my c and a correct?

*March 19, 2013*

**chemistry**

Acetic acid, CH3CO2H, is the active ingredient in vinegar. It's often abbreviated "HOAc". Vinegar is acidic because acetic acid makes H3O+ when it partially ionizes in water: HOAc(aq) + H2O H3O+(aq) + OAc–(aq) Suppose that you have a solution of acetic acid ...

*March 19, 2013*

**chem**

so how do i know if the ph is changing?

*March 18, 2013*

**chem**

Indicate whether the pH increases, decreases, or remains the same when each of the following is added. (CH3NH3)Cl to a solution of CH3NH2 pyridinium nitrate, (C5H5NH)(NO3) to a solution of pyridine, C5H5N sodium formate to a solution of formic acid how do you know these?

*March 18, 2013*

**chemistry**

use a calulater

*March 12, 2013*

**gepmetry**

what grade science is this so i can help you

*March 12, 2013*

**Chem**

hi dan can you help me please on the science tab and it has my name on it hannah please thank you very much and have a very wonderful day

*March 12, 2013*

**science**

Ecological ________ - normal, gradual changes that occur in the types of species that live in an area. Help please and help me fast please!!!!!

*March 12, 2013*

**biology**

if you want to know what it is then go to google and type in your question and there you go and remember to click on the first link to the question so thst way you can know what the correct answer is!!!!!!!!!!

*March 12, 2013*

**chemistry**

thanks! also for this question Calculate the hydronium ion concentration and pH in a 0.037 M solution of sodium formate, NaHCO2. hydronium ion concentration I made an equation: k=x^2/.037-x but when i look up the k what compound am i looking for? how do i know?

*March 7, 2013*

**chemistry**

For each of the following reactions, predict whether the equilibrium lies predominantly to the left or to the right. HCN(aq) + SO42-(aq) CN -(aq) + HSO4-(aq) I think it has something to do with the Ka but im not sure!

*March 7, 2013*

**physics**

An ocean wave travels 17.1 m in 6.7 s. The distance between the two nearest wave crests is 5.1 m. What is the frequency of the wave? Answer in units of H

*March 4, 2013*

**social studies!!!**

Why don't you try to look up the textbook online for that just go on google and type in what your textbook name is and try it! And TELL ME IF IT WORKS OR NOT!!!

*March 4, 2013*

**math**

NOOOOO THAT IS NOT WHAT I MENT I MEANT BY THERE SELFS WHEN THEY HAVE NUMBERS AROUND THE SHAPES AND YOU HAVE TO MULTIPLY THE NUMBERS BY BASE AND THE HIEGHT!!!!!

*March 4, 2013*

**math**

For MATH and its call MULTIPLYING TRAPEZOIDS AND TRIANGLES?

*March 4, 2013*

**math**

hi my name is Hannah and I need help with my math homework it is something to do with multiplying trapezoids and triangles? Also, what are the formula for the shapes so that way i would be able to do my homework? THANKS FOR THE HELP!!!!!!

*March 4, 2013*

**chemistry**

Phenylacetic acid (C6H5CH2COOH) is one of the substances that accumulates in the blood of people with phenylketonuria, an inherited disorder that can cause mental retardation or even death. A 0.021 M solution of C6H5CH2COOH has a pH of 2.99. Calculate the Ka value for this ...

*March 4, 2013*

**chem**

Calculate [OH- ] and pH for each of the following strong base solutions. (Kw = 1.0 10-14.) 3.155 g of KOH in 460.0 mL of solution] how do you do this

*March 3, 2013*

**Chemistry**

How many grams of carbon are in 4.30×1023 molecules of (C3H5)2S?

*March 3, 2013*

**chemistry**

a similar problem i am having troube with is 15.10 mL of 2.00 M HCl diluted to 0.530 L

*March 2, 2013*

**chemistry**

Calculate the pH of each of the following strong acid solutions. 0.697 g of HClO3 in 2.97 L of solution. so i convenrted grams to moles then moles/L to get M of HCl03 then i did -log of that cocentration and put htat as the ph. did i do something wrong? i got 2.415 but it was ...

*March 2, 2013*

**physics**

what caused a little puddle of water to appear under the syringe tip after ten minutes in the sun?

*February 27, 2013*

**chemistry**

why is HS- a stronger BL base compared to HSO4 In a series of oxybases with the same central atom, the base with more O atoms is stronger. In a series of oxybases with the same central atom, the base with less O atoms is stronger. Since H2SO4 is one of the seven strong acids, ...

*February 26, 2013*

**health**

What is atmospheric pressure? A. Pressure of the air inside the body B. Pressure of the air outside the body C. Pressure of the air within one’s mouth D. Pressure of the air within one’s lungs i think its D

*February 25, 2013*

**math**

The price in dollars of a house during a period of mild inflation is described by the formula P(t)=94000 e0.03 t, where t is the number of years after 1990. Answer the following questions: B. In the year 2000 the value will be increasing at a rate of dollars per year. (Round ...

*February 22, 2013*

**calc**

The equation is 94000e^(0.03t)

*February 22, 2013*

**calc**

The price in dollars of a house during a period of mild inflation is described by the formula P(t)=94000 e0.03 t, where t is the number of years after 1990. Answer the following questions: B. In the year 2000 the value will be increasing at a rate of dollars per year. (Round ...

*February 22, 2013*