Wednesday

October 1, 2014

October 1, 2014

Total # Posts: 2,755

**science**

The density of liquid oxygen at its boiling point is 1.14 \rm{kg/L} , and its heat of vaporization is 213 \rm{kJ/kg} . How much energy in joules would be absorbed by 4.0 L of liquid ox
*February 27, 2012*

**Stats**

Explain how to calculate margin of error. What effect does increasing your sample size have on the margin of error? What effect does it have on the confidence level? What effect does it have on the confidence interval?
*February 26, 2012*

**Chemistry**

If a hydrate was found to contain 12% water and the original weight of the sample was 30g, what will be the final weight of the anhydrous sample?
*February 23, 2012*

**Math**

3 quarters, 4 dimes and 4 pennies. .75+.40+.04=1.19
*February 22, 2012*

**statistics**

Find the number z that satisfies the proportion of the observations in a standard normal distribution less than z is 30%?
*February 22, 2012*

**Math**

x= unknown number 1/3x-36=22 is the equation next line 1/3x=22+36 1/3x=58 You must do the inverse operation on both sides of the equation. (1/3x-36+36=22+36)--> (1/3x=58) next line x=174 Again do the inverse operation on both sides. (3/1 x 1/3x=3/1 x 58)-->(x=174)
*February 22, 2012*

**english**

I need examples of a sonnet!
*February 22, 2012*

**maths**

How do I find the derivative of ln(ln(1-x))? I know that the derivative of ln(ln(x)) would be 1/xlnx. Would the answer be 1/(1-x)ln(1-x)?
*February 21, 2012*

**Calculus AB**

Would the answer be (x^4)/4 + (e^3x)/3 + C?
*February 21, 2012*

**physical Science**

When a light bulb is rated at 60 W ft what do this mean?
*February 16, 2012*

**physics**

A slingshot consists of a light leather cup attached between two rubber bands. It takes a force of 25 N to stretch the bands 1.1 cm. a) What is the equivalent spring constant of the rubber bands? Answer in units of N/m b) How much force is required to pull the cup of the ...
*February 16, 2012*

**Physics**

(1290+246)/4 Then use the formula T=2*pi**squareroot*(m/k) to find the answer
*February 16, 2012*

**physics**

A visitor to a lighthouse wishes to determine the height of the tower. The visitor ties a spool of thread to a small rock to make a simple pendulum, then hangs the pendulum down a spiral staircase in the center of the tower. The period of oscillation is 9.71 s. What is the ...
*February 16, 2012*

**Physics**

The distance between two successive crests of a certain transverse wave is 1.12 m. Eight crests pass a given point along the direction of travel every 12.3 s. Calculate the wave speed. Answer in units of m/s
*February 16, 2012*

**Physics**

Why do electric field lines begin on positive charges and end on negative charges?
*February 16, 2012*

**Operations management**

At a major supermarket, checkout time is monitored to improve service quality. For six days, samples each with 20 observations have been obtained, and the following table summarizes the data. Determine if the checkout process is in control or not. You must show your analysis ...
*February 13, 2012*

**Health - Violence and Injury**

1. Which of the following is/are common characteristic(s) of child abusers? a. frustration with life b. has experienced violence in their life c. low socioeconomic status d. All of these 2. Jane is being harassed by a coworker. You would tell her to a. confront the person ...
*February 13, 2012*

**Operations management**

An appliance manufacturer wants to contract with a repair shop to handle authorized repairs. The company has an acceptable range of repair time from 50 minutes to 90 minutes. Two firms have submitted bids for the work. In the evaluation trail, one firm had a mean repair time ...
*February 13, 2012*

**physics**

state whether the variation pressure at nodes in a stationary wave is maximum or zero .justify
*February 13, 2012*

**physics **

two collinear harmonic oscillation x1=8sin(100pie(t)) and x2=12sin(96pie(t)) are superposed.calculate the *maximum and minimum amplitudes *the frequency of amplitude modulation
*February 13, 2012*

**physics**

for a damped harmonic oscillation , the equation of motion is md^2x/dt^2+(gamma)dx/dt+kx=o with m=0.025kg,(gamma)=0.07kg/s and k=85N/m. *calculate the period of motion *number of oscillation in which its amplitude will become half of its initial value *the number of ...
*February 13, 2012*

**physics**

the equation of transverse wave on a rope is y(x,t)=5sin(4.0t-0.02x) where (y) and(x) are measured in cm and (t) in second.calculate the maximum speed of particle on the rope
*February 13, 2012*

**math**

mr spoke is a salesman at pop's cycle shop. each month he earns 800 plus 7% of his total monthly sales. how much did he earn last month if his sales totalled 9200
*February 12, 2012*

**chemistry**

A student is given 3 beakers: Beaker 1- 50.0 ml of a solution produced by dissolving 6.00 grams of a weak monoprotic acid ,HX, in enough water to produce 1 liter of solution. The empirical formula of HX is CH2O. The solution contains 3 drops of phenolphthalein. Beaker 2- A 0....
*February 12, 2012*

**chemisry**

A 0.1 molal solution of a weak monoprotic acid was found to depress the freezing point of water 0.1930C. Determine the Ka of the acid. You can assume 0.1 molal and 0.1 molar are equivalent. 100 ml of a 0.1M solution of the above acid is titrated with 0.1 M NaOH. After an ...
*February 12, 2012*

**Social Studies 7R - DBQ Essay**

taxed them after the french and indian war. they didn't have a lot of rights
*February 12, 2012*

**chemistry**

A 0.1 molal solution of a weak monoprotic acid was found to depress the freezing point of water 0.1930C. Determine the Ka of the acid. You can assume 0.1 molal and 0.1 molar are equivalent.
*February 12, 2012*

**ELA**

pupperoni
*February 12, 2012*

**math**

Mary worked 30 hours this week, five of these hours were on Christmas Day (holiday pay). Determine Mary’s gross pay for this week
*February 11, 2012*

**Geometry**

That's all that the questions says.
*February 8, 2012*

**Geometry**

Bronson and a friend are going to carry a canoe across a flat field, describe the shortest path they can use.
*February 8, 2012*

**Finite Math**

Sinking fund which the goal of $100,000 to reach with n=22, i= 0. 03
*February 7, 2012*

**Microbiology**

You have a broth that contains 2.7x10^7 cfu/ml/ How many colonies would you expect to count on a plate if you spread our: a. 1.0ml? b. 0.1ml?
*February 7, 2012*

**Chemistry**

12865.6
*February 6, 2012*

**geography-grade 7**

How many years has Canada been trading with countries in Europe?
*February 5, 2012*

**chemistry**

so its e?
*February 3, 2012*

**chemistry**

The molecular mass of a substance was determined by the freezing point depression technique. The minimum data required for the determination are a. delta Tf and Kf only. b. delta Tf , Kf and mass of solute. c. delta Tf , Kf , mass of solute and mass of solvent. d. delta Tf , ...
*February 3, 2012*

**algebra**

together, steve and tom sold 130 raffle tickets for their school. steve sold 14 more than three times as many tickets as tom. how many tickets did each boy sell
*February 3, 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. What is the electric potential at a third corner, B, of the square (where there is no charge)?
*February 2, 2012*

**Physics**

Find the electric field at the center of a square of side L = 1.19 cm with charges of Q = +8.16 μC at each corner. Calculate the potential at the center of that square.
*February 2, 2012*

**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*

**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*

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