Sunday

March 29, 2015

March 29, 2015

Total # Posts: 2,923

**Chemistry**

What is the pH of a 0.01M solution of arginine that has a net charge of -.65?
*February 1, 2012*

**Physics**

A point charge q = -2.41 nC is initially at rest adjacent to the negative plate of a capacitor. The charge per unit area on the plates is 4.67 μC/m2 and the space between the plates is 6.53 mm. What is the potential difference between the plates? What is the kinetic ...
*February 1, 2012*

**Physics**

An alpha particle (helium nucleus, charge +2e) starts from rest and travels a distance of 1.88 cm under the influence of a uniform electric field of magnitude 12.2 kV/m. What is the final kinetic energy of the alpha particle?
*February 1, 2012*

**Financial math**

what would be the fee for a buyer to purchase 2 discount points on a home with a sale price of 275,000
*February 1, 2012*

**Chemistry**

Hello, I have a question that reads, "What is the pH of a 0.01M (10mM) solution of arginine that has a net charge of -.65?" I tried using the henderson hasselbach equation, since I know the pka of arginine is 12.48. So I got pH=12.48+log(b/a) Since the net charge was...
*February 1, 2012*

**Physics**

A parallel plate capacitor has a capacitance of 1.71 nF. There is a charge of 0.809 μC on each plate.
*January 31, 2012*

**Physics**

Charges of -10.8 nC and -24.2 nC are separated by 0.813 m. What is the potential midway between the two charges?
*January 31, 2012*

**Physics**

A van de Graaff generator has a metal sphere of radius 14.2 cm. To what potential can it be charged before the electric field at its surface exceeds 2.01 x 106 N/C (which is sufficient to break down dry air and initiate a spark)?
*January 31, 2012*

**Physics**

A beam of electrons traveling with a speed of 3.00 x 107 m/s enters a uniform, downward electric field of magnitude 1.17 x 104 N/C between the deflection plates of an oscilloscope (the figure below ). The initial velocity of the electrons is perpendicular to the field. The ...
*January 31, 2012*

**Physics**

Two parallel plates are 4.85 cm apart. The bottom plate is charged positively and the top plate is charged negatively, producing a uniform electric field of 5.51 x 104 N/C in the region between the plates. What is the time required for an electron, which starts at rest at the ...
*January 31, 2012*

**Chemistry**

The order of the boiling points for the hydrogen halides, except for HF, is HI > HBr > HCl. The reason for this order can be attributed to a) the relative covalent bond strengths. b) differences in hydrogen bonding. c) differences in dipole-dipole attractions. d) ...
*January 31, 2012*

**Physics**

Capacitors are used in many applications where you need to supply a short burst of energy. A 143 μF capacitor in an electronic flash lamp supplies an average power of 12.6 kW to the lamp for 2.95 ms. To what potential difference must the capacitor initially be charged? ...
*January 31, 2012*

**physics**

A certain capacitor stores 473 J of energy when it holds 7.91 x 10−2 C of charge. What is the capacitance of this capacitor? What is the potential difference across the plates?
*January 31, 2012*

**Math**

A scooter factory runs two assembly lines, A and B. 97.4% of line A’s scooters pass instruction, while only 94.9% of line B’s scooters pass inspection. 65% of the factory’s scooters come off assembly line A. a) What is the probability that a randomly selected ...
*January 31, 2012*

**physics**

Charges of +2.38 nC and -1.06 nC are located at opposite corners, A and C, respectively, of a square which is L = 1.13 m on a side (as shown in the figure below ). What is the electric potential at a third corner, B, of the square (where there is no charge)?
*January 31, 2012*

**physics**

A charge of +1.96 mC is located at x = 0, y = 0 and a charge of -3.92 mC is located at x = 0, y = 2.85 m. What is the electric potential due to these charges at a point with coordinates x = 4.01 m, y = 0?
*January 31, 2012*

**Math**

Two students, Jim and Joan, are registered for the same class and attend independently to each other, Jim 91.9% of the time and Joan 84.3% of the time. What is the probability that on any given day a) at least one of them will be in class? b) neither will be in class?
*January 30, 2012*

**Physics**

An automobile accelerates from rest at 2.4 m/s2 for 29 s. The speed is then held constant for 11 s, after which there is an ac- celeration of −2.2 m/s2 until the automobile stops. What total distance was traveled? Answer in units of km
*January 28, 2012*

**statistics**

A survey about the art program at a school found that 250 students wanted an after-school art program, 150 students wanted art classes during the day, and 100 students thought that the school should have no art program. If a circle graph were made from this data, what would be...
*January 28, 2012*

**Chemistry**

Naturally occurring copper contains a mixture of 69.09% copper-63 (63.9298 amu) and 30.91% copper-65 (64.9278 amu). What is the average atomic mass of copper?
*January 27, 2012*

**Intermediate College Algebra**

-4(3y-4)+12y
*January 25, 2012*

**Physics**

E= KQ/r2 E= 5.07E3 N/C K= 8.99E9 Q= 1.24E-6 solve for R
*January 25, 2012*

**Physics**

In lab tests it was found that rats can detect electric fields of about 5.07 kN/C or more. If a point charge of 1.24 μC is sitting in a maze, how close must the rat come to the charge in order to detect it?
*January 25, 2012*

**Physics**

Some forms of cancer can be treated using proton therapy in which proton beams are accelerated to high energies, then directed to collide into a tumor, killing the malignant cells. Suppose a proton accelerator is 4.21 m long and must accelerate protons from rest to a speed of ...
*January 25, 2012*

**thesis statement**

I need to come up with a good thesis statement for Amy Tan "Mother Tongue" and Gloria Anzaldua "how to tame a wild tongue". I have to do a point by point comparison essay & I can't really come up with a theses :( Help?!
*January 24, 2012*

**Physics**

In lab tests it was found that rats can detect electric fields of about 5.07 kN/C or more. If a point charge of 1.24 μC is sitting in a maze, how close must the rat come to the charge in order to detect it?
*January 24, 2012*

**Physics**

In a cathode ray tube, electrons initially at rest are accelerated by a uniform electric field of magnitude 4.71 x 105 N/C during the first 5.49 cm of the tube's length; then they move at essentially constant velocity another 47.9 cm before hitting the screen. Find the ...
*January 24, 2012*

**Chemistry**

A 10.0 mL volvume of Ultra Bleach is diluted in a volumetric flask. A 25.0 ml sample of this solution is analyzed accordign to the procedure in this experiment. Given that 33.75 mL of 0.135 M Na2S2O3 are needed to reach the stochiometric point, answer the following. a. How ...
*January 24, 2012*

**statistics**

Heights of young adult U.S. women are approximately normal with mean 64" and standard deviation 2.7". What proportion of all U.S. young adult women are taller than 6 feet?
*January 23, 2012*

**English ~ Clauses**

Hey guys! I was hoping that someone could look over my answers & help me out with the ones I didn't get? Thanks :) Directions: Identify the subordinate clause. Tell whether it is a noun, adj, or adv. clause. Indicate whether it's introduced by a relative pronoun, ...
*January 23, 2012*

**Algebra**

What are two points for the solution 12x+14y=70 ?
*January 21, 2012*

**Math**

X=177
*January 20, 2012*

**financial accounting**

Connection Station, an internet café, had the following operating activities during the month of May: 1. Bought 800 in jump drives and disks, which are available for resale from Office Depot on credit 2. Paid 900 in utilities for the month of may 3. Paid 2000 rent for ...
*January 20, 2012*

**physics-Please HELP!**

What percent error is introduced by weighing a Styrofoam block in air, which exerts an upward buoyancy force, rather than in vacuum? The density of air is 1.2 kg/m^3. (The density of Styrofoam is 160 kg/m^3)
*January 16, 2012*

**Nutrition**

You decide to perform proximate analysis on a sample from your best friend's diet. Most abundant component(s) in nitrogen free extract of diet would be: a) insoluble fibre b) starch c) triglyceride d) Sodium and potassium I know the correct answer is b) starch but if ...
*January 14, 2012*

**english**

how do i correct this sentence "I am both a quick worker and careful." to be a parallel
*January 10, 2012*

**history**

what rules and assumptions of the 1780s no longer necessarily "fit" the 1830s.
*January 1, 2012*

**arithmetic**

The sum of the first 4 terms of an arithmetic series is -8 and the sum of the first 5 terms is 85. Determine the first term and the common difference
*December 27, 2011*

**Communications Studies **

What are the three technologies on which the primary mass media are built?
*December 17, 2011*

**Communications Studies **

How has a trusteeship concept for broadcast regulation given way to a marketplace model? Consider technological shifts.
*December 17, 2011*

**Communications Studies **

How do scholars differ on whether media-depicted violence triggers aggressive behavior?
*December 17, 2011*

**algebra**

find the variation constant and an equation of variation where y varies directly as x and y= 24 when x=6
*December 15, 2011*

**Calc**

find the volume of the solid obtained by rotating the region bounded by the given curves about the specified axis y=x^2+1; y=9-x^2; about y=-1
*December 15, 2011*

**geometry**

a slide 5.4 meters long makes an angle of 29 degrees with the ground. How far above is the top of the slide?
*December 15, 2011*

**Calculus**

Identify the open intervals on which the graph of f(x)=3/(x^2+12) is concave up and/or concave down. Please give in interval form.
*December 15, 2011*

**Calculus**

integrate: (x^2-3)sqrt (x+5)
*December 14, 2011*

**math algebra 2**

solve for x 3x-6=18
*December 14, 2011*

**math**

Ben has 15 puzzles and 27 CDs. When he takes a tgrip, he likes to bring one puzzle and one CD as entertainment. How many trips can he take with a different puzzle and CD pair?
*December 12, 2011*

**trig**

Prove that the statement is an identity: (tanx/cscx)=(1/cosx)-cosx
*December 7, 2011*

**chemistry**

if you react 37.0ml of .762M sulfuric acid, how many liters of carbon dioxide gas are produced at a pressure of 725mm Hg and a temperature of 21 degrees celsius
*December 6, 2011*

**Language **

What is the deffinition for symertry and a sentence
*December 5, 2011*

**chemistry**

What is the molarity of OH- in an aqueous solution that is 0.17 M HClO4?
*December 4, 2011*

**geometry**

a right angle triangle is divided into 2 triangles. the right triangle angles measures are: 68 and 90. The other triangle angle measure is 55, what are the measurement of the 2 missing angles?
*November 30, 2011*

**Chemistry**

ZnCl2(aq)+Na2CO3(s)--> ZnCO3(s)+NaCl (aq) Balance the chemical equation and state solid, liq, gas, aq properly to each compound Ok I have it balanced by 2 NaCl in the second part of the equation But now what is the total ionic and net ionic equations?
*November 30, 2011*

**Chemistry**

AlCl3(aq)+ NH4OH(aq)-> Al(OH)3(s) + NH4Cl(aq) AlCl3(aq)+ 3NH4OH(aq)-> Al(OH)3(s) + 3 NH4Cl(aq)... is balanced-- Now total ioic?? Is this right?? : Al +3Cl+3NH4 +OH --> Al+ 3OH+ 3NH4+ 3Cl Crossing out on both sides I end up with OH --> 3OH I do not know what to do ...
*November 30, 2011*

**chemistry**

Silver is electroplated at the cathode of an electrolysis cell by 1/2 reaction Ag(aq) + e- --> Ag(s). How many moles of electrons are required to electroplate 5.8g of Ag?
*November 30, 2011*

**chemistry**

In a hydrocarbon-based combustion reaction, what two molecules are most likely to be products? A. carbon dioxide and water B. sulfur dioxide and zinc oxide C. sulfur dioxide and cyclopentane D. carbon monoxide and hydroxide
*November 29, 2011*

**chemistry**

What is produced during all combustion reactions? A. ions B. solids C. energy D. nuclear material
*November 29, 2011*

**chemistry**

Choose the term that best describes the following chemical reaction: C10H8 + 12 O2 10 CO2 + 4 H2O A. synthesis B. combustion C. electrolytic D. decomposition
*November 29, 2011*

**chemistry**

Which one of the following is a combustion reaction? A. CH4 + 2 O2 CO2 + 2 H2O B. HBr + NaOH NaBr + H2O C. Xe (aq) + H2O(l) HXe(aq) + OH- (aq) D. NaCl (aq) + AgNO3 (aq) NaNO3 (aq) + AgCl (s)
*November 29, 2011*

**English**

i think web sites
*November 29, 2011*

**chemistry**

sorry on that first post.. I was mixing two problems But I also need help ith that first equation also the ZnCl2 one.... Thanks
*November 29, 2011*

**chemistry**

AlCl3(aq)+ NH4OH(aq)-> Al(OH)3(s) + NH4Cl(aq) AlCl3(aq)+ 3NH4OH(aq)-> Al(OH)3(s) + 3 NH4Cl(aq)... is balanced NOw total ioic?? Is this?? : Al +3Cl+3NH4 +OH --> Al+ 3OH+ 3NH4+ 3Cl Crossing out on both sides I end up with OH --> 3OH I do not know what to do or how it...
*November 29, 2011*

**chemistry**

ZnCl2(aq)+Na2CO3(s)--> ZnCO3(s)+NaCl (aq) Balance the chemical equation and state solid, liq, gas, aq properly to each compound Ok I have it balanced by 2 NaCl in the second part of the equation But now what is the total ionic and net ionic equations. I think: Al +3Cl+3NH4...
*November 29, 2011*

**math**

Inncorect-because twenty eight divided by four is seven and seven is not an even number.
*November 28, 2011*

**physics**

The velocity of the transverse waves produced by an earthquake is 8.9 km/s, and that of the longitudinal waves is 5.1 km/s. A seismograph records the arrival of the transverse waves 68 s before the arrival of the longitudinal waves. How far away was the earthquake?
*November 26, 2011*

**physics**

11 newtons
*November 25, 2011*

**college math**

a license plate is to consist of three digits followed by two uppercase letters. determine the number of different license plates possible. the first digit cannot be zero and repition is not permitted.
*November 22, 2011*

**chemistry**

How much of the water (in grams or mL) is consumed to produce 15 mL of the H2 gas
*November 22, 2011*

**Algebra II**

The intensity of illumination at a given point is directly proportional to the intensity of the light source and inversely proportional to the square of the distance from the light source. If a desk is properly illuminated by a 74.0 w lamp 8.00 ft from the desk, what size lamp...
*November 22, 2011*

**Algebra II**

The volume of a given weight of gas varies directly as its absolute temperature t and inversely as its pressure p. If the volume is 4.45 m^3 when p=225 kilo pascals (kpa) and t = 305 K, find the volumn when p = 325 kpa and t = 354 k.
*November 22, 2011*

**Algebra II**

The amount paid to a work crew varies jointly as the number of persons working and the length of time worked. If 5 workers earn $5123.73 in 3.0 weeks, in how many weeks will 6 workers earn a total of $6148.48?
*November 22, 2011*

**Algebra II**

The maximum safe load of a rectangle beam varies jointly as its width and the square of its depth and inversely as the length of the beam. If a beam 8.00 in. wide, 11.5 in. Deep, and 16.0 ft long can safely support 15.000 lb, find the safe load for a beam 6.50 in. Wide, 13.4 ...
*November 22, 2011*

**Algebra II**

The maximum safe load of a rectangle beam varies jointly as its width and the square of its depth and inversely as the length of the beam. If a beam 8.00 in. wide, 11.5 in. Deep, and 16.0 ft long can safely support 15.000 lb, find the safe load for a beam 6.50 in. Wide, 13.4 ...
*November 22, 2011*

**Algebra II**

The kinetic energy of a moving body is directly proportional to its mass and the square of its speed. If the mass of a bullet is halved, by what factor must its speed be increased to have the same kinetic energy as before?
*November 22, 2011*

**Algebra II**

If y varies jointly as w and x, and y is 483 when x is 742 and w is 383, find y when x is 274 and w is 756.
*November 22, 2011*

**Algebra II**

The area of a triangle varies jointly as its base and altitude. By what percent will the area change if the base is increased by 15% and the altitude decreased by 25%?
*November 21, 2011*

**Algebra II**

If 750 m of 3.00-mm-diameter wire has a resistance of 27.6, what length of similar wire 5.00 mm in diameter will have the same resistance?
*November 21, 2011*

**Algebra II**

If both masses are increased by 60% and the distance between them is halved, by what percent will the force of attraction increase?
*November 21, 2011*

**Linear Programming**

Riverside oil company in eastern Kentucky produces 3 different grades of gasoline. They are regular, premium, and supreme grades. Each barrel of regular grade sells for $77 while premium grade sells for $82 per barrel and supreme grade sells for $89 per barrel. Petroleum ...
*November 17, 2011*

**statistics/psych**

Find TWO media examples of two types of correlations (explained below). You will have to do some research to find these. Next: (1) Find one media example (don�t make up your own) of a correlation that could be argued to be spurious (third variable). Explain your media ...
*November 16, 2011*

**statistics/psyc**

Researchers are interested in the effectiveness of a particular treatment for insomnia. Fifty insomnia sufferers who responded to a newspaper ad are contacted, and each is given a pill with instructions to take it before going to sleep that night. The pill actually contains ...
*November 16, 2011*

**statistics**

2.5
*November 16, 2011*

**geometry**

find x if m<2=9x+3 and m<DBC=21x-3
*November 15, 2011*

**chemistry**

I need to find out Molar solubility of CuS. How many grams of CuS are present in 15.0 L of a saturated CuS solution,
*November 14, 2011*

**chemistry**

Thanks Dr Bob The Ksp = 4.96 x 10^-9, so the second one I was using was the correct one, Reaching the M wasn't the hard part But I am still not sure of the equation. I will ask my teacher today in class. Somehow I came up with 52.133L but I did not factor the H2O in there ...
*November 14, 2011*

**chemistry**

Thank you Dr Bob!! I was thinking most of the same that you said, even about the 1:1 ratio, and my book had most of the actual compounds stated about being insoluble IN WATER. I was just was trying to figure it all out and make sense of the values and the insoluble compounds, ...
*November 13, 2011*

**chemistry**

what one is the Most Soluble compound 1) CuS, Ksp = 1.27 x10^-36 2) PbS, Ksp = 9.04 x 10^-29 3) AgCl,Ksp = 1.77 X 10^-10 4) AgI, Ksp = 8.51 x 10^17 5) Not enough information. My book states that AgCl is insoluble in water and so are MOST phosphates and Sufides, and I am ...
*November 13, 2011*

**Please Help!!!!!!**

a hot air balloon is rising vertically 10 ft/sec while the wind is blowing horizontally 5ft/sec. Find the speed of the balloon and the angle x that it makes with the horizontal. I know that the speed of the balloon is the square root of (10)^2 + (5)^2, but I was wondering if ...
*November 10, 2011*

**reading**

Is flying, cried, clapped, try, shook are consonant clusteres
*November 9, 2011*

**Calculus**

Consider f(x)=200+8x^3+x^4. find the intervals on which function is increasing or decreasing, the local max and minimu values, the intervals of concavity and the inflection points
*November 9, 2011*

**Math**

How long will it take 7500 to triple itself if it is invested at 7% simple interest?
*November 9, 2011*

**physics**

Suppose you increase your walking speed from 1m/s to 3m/s in a period of 1s. What is your acceleration? a:2m/s b:5m/s c:4m/s d:3m/s
*November 9, 2011*

**Please Help!!!!!!**

From the top of a lighthouse 55ft above sea level, the angle of depression to a small boat is 11.3 degrees. How far from the foot of the lighthouse is the boat?
*November 8, 2011*

**Science**

If you mix 40.0 grams of Cu with 50.0ml of 1.20 M HNO3 solution, how many grams of NO gas can be made?
*November 7, 2011*

**General Chemistry **

Calculate the theoretical pH after 2.50 mL and 9.50 mL of NaOH has been added in both the titration of HCl and of HC2H3O2. Indicate if the volume of NaOH is before or after the equivalence point. Compare these theoretical values with the actual values found on the titration ...
*November 6, 2011*

**Physical Science **

DISTANCE-TIME for RUNNERS Time(s) 1 2 3 4 Sally's Distance(m) 2 4 6 8 Alonzo's Distance(m) 1 2 2 4 Make a distance-time graph that shows the motion of both runners. What is the average speed of each runner? Which runner stops briefly? Over what time interval do they ...
*November 3, 2011*

**chemistry**

How much heat is absorbed by the calorimeter if the temperature change is 10 C and the calorimeter constant (Heat Capacity) is 3.3 J/K?
*November 3, 2011*

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