Sunday

August 31, 2014

August 31, 2014

Total # Posts: 6,208

**physic**

Find the net change in entropy when 259 g of water at 0.0°C is added to 259 g of water at 97.5°C.
*May 13, 2011*

**Astronomy**

Which of the following developments was most directly responsible for the creation of rockets that were capable of going to the moon? A. gunpowder B. explosives C. single-stage rockets D. multistage rockets
*May 13, 2011*

**Physics**

I've tried a bunch, have no idea. Got the first part, no idea on the second one. A basketball, of mass m = 0.45 kg is dropped, from rest, from a stationary hellicopter at a high altitude. Use g = 9.81 N/kg. (a) If air resistance is negligible, using energy considerations ...
*May 12, 2011*

**CALCULUS HELP PLEASE!!**

Intergral from -2 to 2 (-2 is at the bottom of the integral sign and 2 is at the top) x^-2dx = -x^-1] (the bracket has a 2 at the top and -2 at the bottom) = -(2)^-1-(-(-2)^-1) = (-1/2)-(1/2) = -1 Is this true or false. I think it's false, but can someone explain to me why...
*May 11, 2011*

**Calculus**

Intergral from -2 to 2 (-2 is at the bottom of the integral sign and 2 is at the top) x^-2dx = -x^-1] (the bracket has a 2 at the top and -2 at the bottom) = -(2)^-1-(-(-2)^-1) = (-1/2)-(1/2 = -1 Is this true or false. I think it's false, but can someone explain to me why ...
*May 11, 2011*

**MATH**

How do you factor (x^2)+x+7?
*May 10, 2011*

**keyboarding and word processing**

When creating a 20-page newsletter in which you want different margin settings and other page formats within the multipage document, which one of the following Word features should you use?
*May 10, 2011*

**Chemistry**

The smaller molecules that make up complex carbohydrates are called A. sugars B. amino acids C. fatty acids D. nucleotides
*May 10, 2011*

**statistics**

A consumer group is testing a manufacturer’s claim that a new car model will travel at least 30 miles per gallon of gasoline. Assume that ��0:��=30 and ����:��<30, and that the population standard ...
*May 9, 2011*

**statistics**

what the error is: a) Grade Percent Frequency A 20% B 45% C 30% D 10% F 5% (b) The following table summarizes the grade breakdown on an exam in a small statistics class with 10 students. Grade Percent Frequency A 30% B 35% C 15% D 20% F 0%
*May 9, 2011*

**statistics**

Washington University banned smoking on the Hilltop campus starting in 2010. The student paper decides to do an opinion poll to see if current campus students/faculty/staff support the ban. Reporters are about to start asking a sample of 250 Hilltop people for their opinions...
*May 9, 2011*

**engineering**

How is bacteria used in genetic engineering?
*May 8, 2011*

**physics-nuclear reactors**

this sso guy is nuts if he thinks we should be able to do this...
*May 8, 2011*

**Physical science**

Calculate the total number of ions in 2,0g K2SO4
*May 7, 2011*

**math**

according to what rule are the numbers arrange 8-9-7-10-12-20-28-29?
*May 7, 2011*

**logos**

Search "amazing logos" in a search engine like Google.
*May 6, 2011*

**Math**

Integrate[[E^(y/x),{y,0,1},{x,y,1}] Solution:0.859141 or .5*(e-1) I can't figure out what to do,and I tried substitution.
*May 6, 2011*

**Chemistry**

A quantity of sulfuric acid is added to 100. mL of water. The final volume of the solution is 111 mL and has a density of 1.14 g/mL. What mass of acid was added? Assume the density of the water is 1.00 g/mL.
*May 6, 2011*

**Poetry**

No thats my sister...we both suck at poety:( we are in the same class
*May 4, 2011*

**Poetry**

I need a seven long line iambic pentameter poem describing something. It can be anything. PLEASE HELP...I have no idea how to do this and my teacher will fail me. please please help
*May 4, 2011*

**Poetry**

Hang out with friends. I think I want my poem describing love. I came up with this one but its not in iambic pentameter form what so ever. and I have no clue how to change it Love, unconditional, unbreakable, unmistakable . A beating within your heart unstoppable. The ...
*May 4, 2011*

**chemistry**

Oh yeah! Thanks, so you would substitute: (10)(100) = (3)(x) to get: x = 333.33 mL, right?
*May 3, 2011*

**chemistry**

I need help with this problem: if you want to reduce the strength of 100 mL of 10 N NaOH to 3N, how much water would you need to add? Thanks in advance.
*May 3, 2011*

**Physics**

m = .150kg v = 40m/s Theta = 30 degrees Vh = 40*cos(30)>>>>Vh = 34.64m/s KE = (1/2)(.150kg)(34.64)^2>>>>KE = 90J
*May 3, 2011*

**Physics**

asdfadsf
*May 3, 2011*

**ECONOMICS**

Two price setting firms have the same price and marginal revenue functions but face different cost functions. These functions are provided below. P = 165 - 0.025Q MR = 165 - 0.05Q Firm 1: TC = 4,000 + 15Q Firm 2: TC = 3,000 + 22Q a. Assuming that both firms are profit-...
*May 3, 2011*

**Biology**

What ethical issues might arise when a drug company funds trials of a new drug it has developed to treat a genetic disorder?
*May 3, 2011*

**Chemistry**

The alkanes mostly have dispersion forces acting among them,,so CH4 is dispersion forces as well as for c3h8 and c2h5 is ethyl which likean alkane..
*May 2, 2011*

**8th grade math**

3.5 X 10 ________ 7 x 10^-9
*May 1, 2011*

**physics**

You are driving your race car around a circular test track. Which would have a greater effect on the magnitude of your acceleration, doubling your speed or moving to a track with half the radius? Why
*May 1, 2011*

**Algebra**

What is the number of units in the distance from the origin to the point (-8,6) in a coordinate system?
*May 1, 2011*

**calculus**

Please help find the solution to the initial value problem dy/dx=(1+2cos^2 x)/y with(y>0), and y=1 when x=0. Thanks.
*April 29, 2011*

**Algebra**

find the LCM of 6y^6and 12y^8
*April 26, 2011*

**Sociology**

Which sociological perspective holds the view that people create their social worlds through interaction and manipulation of symbols?
*April 23, 2011*

**CRIMINOLOGY**

In what areas should the federal authorities not become involved?
*April 23, 2011*

**Chemistry**

An aqueous solution of an unknown compound boils at 101.00 degrees Celsius (760 torr). What is the molality, and freezing point of this solution?
*April 21, 2011*

**social studies**

where is antigua volcano
*April 19, 2011*

**statistics**

) Overproduction of uric acid in the body can be an indication of cell breakdown. This may be an advance indication of an illness such as gout, leukemia, or lymphoma. Over a period of months, an adult male patient has taken eight blood tests for uric acid. His mean ...
*April 18, 2011*

**Chemistry**

You are in the silver recovery business. You receive 55‐gal drums of waste silver solution from photography laboratories, metal plating operations, and other industrial companies. Currently, you have a drum of waste from a silver‐plating factory with the silver ...
*April 18, 2011*

**literature**

Why the Nurse is eager for Paris to marry Juliet?
*April 18, 2011*

**Chemistry**

Ammonium sulfate reacts with a solution of sodium hydroxide to produce sodium sulfate, ammonia gas and water. Calculate the yield in grams of ammonia gas that would form; and the amount of excess reagent in grams that would be left in the flask, after 9.92 grams of ammonium ...
*April 17, 2011*

**physics**

A 10-kg object is falling vertically through moist air. If its acceleration is observed to be 6 m/s/s, what is the resistance in newtons offered by the air?
*April 17, 2011*

**trig**

Peter (P) and Jamie(J) have computer factories that are 132 miles apart. They both ship their completed parts to Diane (D). Diane is 72 miles from Peter and 84 miles from Jamie. Using the points D,J,and P to form a triangle, find m<PDJ to the nearest tenth of a degree.
*April 16, 2011*

**reading **

working on a crosword puzzle it has 9 letter and the words given are watermark; paper;________;person help please
*April 14, 2011*

**reading**

crossword puzzle 9 letters words given watermark;paper::________;person
*April 14, 2011*

**reading**

crossword puzzle 6 letters words given square;perpendicular;:triangle;________
*April 14, 2011*

**reading**

working on a crossword puzzle it has 8 letters and the words are grammer;______;:scale;music
*April 14, 2011*

**Math**

compound and interest Using the below values please calculate the amount accumulated (future value) *Initial principal=$2000 *Interest Rate=9% *Number of years 7 *Monthly compounding
*April 14, 2011*

**Math**

More detils plese..
*April 13, 2011*

**Math**

compound and interest Using the below values please calculate the amount accumulated (future value) *Initial principal=$2000 *Interest Rate=9% *Number of years 7 *Monthly compounding
*April 13, 2011*

**math 234 calc 4 !!!!!!!!!!!**

write this function in terms of heaviside functions, and then show your work in finding its laplace transform f(t)= o if o < t<3 t-3 if 3lessthan or equal <lessthan or equal to t < 6 o if 6< t < infinity
*April 12, 2011*

**MATH !!!!!!!!! HELP**

Find the exact value (either decimal or fraction form) of the first term of an arithmetic sequence if the sum of the first 100 terms is 7099.5 and the sum of the next 100 terms is 20799.
*April 12, 2011*

**Math**

ten pounds of potatoes cost $2.55. How much will 6 pounds cost? Write and solve a proportion. Justify your steps.
*April 12, 2011*

**physics**

In an experiment to determine the rate at which heat is extracted from a hot material, 305 g of the material at 90 °C is put into a 50 mm diameter copper vessel to a depth of 90 mm as shown below. The hot material and calorimeter are placed in a container holding 189 g of ...
*April 12, 2011*

**sarah**

In an experiment to determine the rate at which heat is extracted from a hot material, 305 g of the material at 90 °C is put into a 50 mm diameter copper vessel to a depth of 90 mm as shown below. The hot material and calorimeter are placed in a container holding 189 g of ...
*April 12, 2011*

**physics**

In an experiment to determine the rate at which heat is extracted from a hot material, material at 90 °C is put into a copper vessel. The hot material and calorimeter are placed in a container holding cold water at 22.7 °C. The temperature of the water is then measured...
*April 12, 2011*

**physics**

In an experiment to determine the rate at which heat is extracted from a hot material, 305 g of the material at 90 °C is put into a 50 mm diameter copper vessel to a depth of 90 mm as shown below. The hot material and calorimeter are placed in a container holding 189 g of ...
*April 12, 2011*

**chemistry**

A gas has a volume of V1 = 550 mL. If the temperature is held constant, what volume would the gas occupy if P2 = 22 P1?
*April 11, 2011*

**Lotto 5/90 maths**

how can i get the next number of lotto
*April 11, 2011*

**physics**

You throw a ball straight up in the air. The instant after leaving your hand the ball’s speed is 30 m/s. Ignoring the effects of air resistance, predict how fast the ball is traveling 2 seconds later? Where is it at this time?
*April 10, 2011*

**physics**

In Fig. 12-39, a climber with a weight of 441 N is held by a belay rope connected to her climbing harness and belay device; the force of the rope on her has a line of action through her center of mass. The indicated angles are θ = 45˚ and φ = 25˚. If her ...
*April 8, 2011*

**Finance**

(Break-even analysis) Acquiring more energy-efficient equipment would cost $80,000 now and yield savings of $20,000 in energy costs every year for the next 8 years, after which its salvage value will be 0. The discount rate is 8%. (1) Based on a before-tax analysis, what is ...
*April 8, 2011*

**physics**

Two particles, each of mass 6.00 kg and speed 4.67 m/s, travel in opposite directions along parallel lines separated by a distance 4.89 m. What is the magnitude of L, the angular momentum of the two-particle system around a point midway between the two lines?
*April 7, 2011*

**physics**

a climber with a weight of 441 N is held by a belay rope connected to her climbing harness and belay device; the force of the rope on her has a line of action through her center of mass. The indicated angles are θ = 45˚ and φ = 25˚. If her feet are on the ...
*April 7, 2011*

**chemistry**

Cobalt-60 is radioactive isotope used to treat cancers. A gamma ray photon emitted by this isotope has an energy of 2.13 x 10—13 J. What is the wavelength of this gamma ray in SI unit?
*April 7, 2011*

**Chemistry**

Tooth enamel is made up of hydroxyapatite, Ca_10(PO_4)_6(OH)_2 or the empirical formula, Ca_5(PO_4)_3(OH). Use the empirical formula for all calculations because stoichiometry plays two significant roles. A. Print the balanced chemical equation for the molar solubility of ...
*April 7, 2011*

**chemistry**

The Ka for hydroflouric acid is 4.5 *10^-4 at 298K. Calculate the amount of sold NaF that is required toprepare a 250. mL acidic buffer with pH = 2.75. The inital molarity of hydroflouric acid is .250M but you have only 75mL. Part 2 Recalculate the pH of the buffer prepared in...
*April 6, 2011*

**physics**

How does pressure work as a restoring force to create a sound wave?
*April 6, 2011*

**Math**

$50.40
*April 6, 2011*

**algebra 2**

what is 7^1/2 divided by 7^3/5
*April 6, 2011*

**algebra 2**

what is 7^1/2 divided by 7^3/5
*April 6, 2011*

**Chemistry **

Calculate the pH of the buffere prepared if 40.0 mL of .2M NaOH is added. The previous buffer is made from HF an NaF... assume all necessary information is known about this buffer. Print an equation that shows how the NaOH is consumed by the buffereing agents. Which side does ...
*April 6, 2011*

**Chemistry**

Calculate amount of solid NaF required to prepare a 250mL acidic buffer with pH=2.75. The initial molarity of HF is .25M but you only have .075L of it. I have tried many different ways... the most recent and seems to be simplest was using H-H equaion and solving for the CB/CA ...
*April 6, 2011*

**Chemistry**

Nevermind I figured it out
*April 5, 2011*

**Chemistry**

In a standard hydrogen electrode, why does increasing the partial pressure of H2 gas reduce the standard potential (E) of the cell?
*April 5, 2011*

**Trig**

A 60 ft. antenna stands on top of a building, From a point on the ground, the angles of elevation to the top and bottom of the antenna measure 58 and 44 respectively. How tall is the building
*April 5, 2011*

**Math**

Mrs.dude is buying 2 pounds of chocolate for $7.50 . Write an expression to find the cost of 4.5 pounds of chocolate
*April 5, 2011*

**Physics Simple Harmonic Motion**

A sewing machine needle moves with a rapid vibratory motion, rather like SHM, as it sews a seam. Suppose the needle moves 8.4 mm from its highest to its lowest position and it makes 27 stitches in 8.5 s. What is the maximum needle speed?
*April 5, 2011*

**Physics Simple Harmonic Motion**

The displacement of an object in SHM is given by y(t) = (7.0 cm)sin[(1.58 rad/s)t]. What is the frequency of the oscillations?
*April 5, 2011*

**Physics**

A 0.55-kg mass is suspended from a string, forming a pendulum. The period of this pendulum is 1.2 s when the amplitude is 2.2 cm. The mass of the pendulum is now reduced to 0.27 kg. What is the period of oscillation now, when the amplitude is 2.4 cm?
*April 5, 2011*

**physics**

Suppose 0.0150 kg of steam (at 100.00°C) is added to 0.150 kg of water (initially at 19.3°C.). The water is inside a copper cup of mass 54.1 g. The cup is inside a perfectly insulated calorimetry container that prevents heat flow with the outside environment. Find the ...
*April 5, 2011*

**physics**

what is the weight of a square whose thickness is 10mm
*April 4, 2011*

**algebra**

Donna must choose a number between and that is a multiple of , , and . Write all the numbers that she could choose. If there is more than one number, separate them with commas.
*April 3, 2011*

**AP Chemistry**

Thanks! But im confused on why you would subtract the .0637g in 120mL from .265g in 500mL. Why dont you do (grams from 500mL-grams from 380mL)?
*April 1, 2011*

**AP Chemistry**

Oh sorry the Ksp=4x10^(-5)
*April 1, 2011*

**AP Chemistry**

A 500ml saturated solution of MgCO3 (M=84) is reduced to 120 ml by evaporation. What mass of solid MgCO3 is formed? The answer is 0.20g, I just need a detailed explanation. Thanks!
*April 1, 2011*

**physics**

A 20.0 \mu F capacitor initially charged to 20.0 \mu C is discharged through a 1.90 k\Omega resistor. How long does it take to reduce the capacitor's charge to 5.00 \mu C?
*April 1, 2011*

**chemistry**

How many grams of magnesium iodide are needed to make 125 ml of a 5M solution
*March 31, 2011*

**math**

1. Select any two integers between -12 and +12 which will become solutions to a system of two equations. 2. Write two equations that have your two integers as solutions. Show how you built the equations using your integers. Your solution and equations should not be the same ...
*March 31, 2011*

**calculus**

Thank you Reiny for replying.I know names have changed. Perhaps I should put I need to differentiate the function f(x)=(x^2-6x+23)^3/2 by the chain rule.
*March 31, 2011*

**calculus**

Please can someone help. I need to use the composite rule to differentiate the function f(x)=(x^2-6x+23)^3/2. Any help would be greatly appreciated.
*March 31, 2011*

**Chemistry**

If 25.5 grams of NaOH is dissolved in 750 ml of water, find: [H+]= [OH-]= pH= pOH=
*March 29, 2011*

**physics**

A 14 kg body is moving through space in the positive direction of an x axis with a speed of 220 m/s when, due to an internal explosion, it breaks into three parts. One part, with a mass of 6.4 kg, moves away from the point of explosion with a speed of 190 m/s in the positive y...
*March 29, 2011*

**Chemistry**

The following reaction can be used to determine the amount of calcium ion present in milk. Before the reaction below is carried out ca2+ is precipitated out of a sample of milk as CaC2O4(s). The CaC2O4(s) is then titrated with MnO4-. 2MnO4-(aq) + 5CaC2O4(s) + 16H+(aq) = 2Mn2+(...
*March 29, 2011*

**physics**

Your spacecraft is in a circular, geostationary orbit around earth and you would like to fly to the moon. Draw a suitable Hohmann transfer orbit that will get you there. How long does the journey take? (Neglect the gravitational fields of the moon and the sun for this problem...
*March 27, 2011*

**physics**

Muons are elementary particles that have a very short lifetime of about two millionth of a second (when at rest). They can be created in the upper atmosphere (at an altitude of say 10,000 meters) by cosmic rays, in which case they travel towards the surface of the Earth at ...
*March 27, 2011*

**Physics**

Kf+Uf=Ki+Ui .5*m*v^2 + 0=.5*m*(vi)^2 + m*9.8*1.3meter m=mass v= velo u want to solve for vi= your initial velo, for you 14m/s my values where .16kg ball, 13m ceiling, 1.7 off the ground. answer one for me was 14.88, answer 2 was 15.96m/s
*March 27, 2011*

**Finance**

Risk-adjusted discount rate Answer: e Diff: M A: Inputs: CF0 = -25000; CF1 = 13000; Nj = 3; CF2 = 18000; I = 12. Output: NPVA = 17,663.13. B: Inputs: CF0 = -42663.13 (-25000 + -17663.13); CF1 = 15247; Nj = 4. Output: IRR = 16.0% = k. Risk-adjusted discount rate Answer: e Diff: M
*March 26, 2011*

**Statistics**

Hi am having trouble finding the lamda value for this question the below I tried different methods but they don't make sense. I know for everyone 25 metres theirs 1 nick. A coil of wire has 500 metres of wire. Suppose there are 20 nicks (the most common problem with wire) ...
*March 26, 2011*

**English 101**

I want to convince my audience that the other position is not correct and my position has a better decision
*March 26, 2011*

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