Wednesday

October 26, 2016
Total # Posts: 813

**chemistry**

how many moles of BaCl2 are in 300 g of H2O if the molality is 0.2 m?

*November 25, 2014*

**Statistics **

Random samples of size n = 90 were selected from a binomial population with p = 0.4. Use the normal distribution to approximate the following probabilities. (Round your answers to four decimal places.) (a) P(p̂ ≤ 0.49) = (b) P(0.37 ≤ p̂ ≤ 0.49) = ...

*November 3, 2014*

**Algebra**

The number will it was hard a little but not that hard so yeah I'm

*October 28, 2014*

**physics**

A diving bell has a weight of 30000 N when measured on shore. In the water, suspended by a cable, the tension in the cable is only 12000 N. What is the buoyant force, FB, on the diving bell when it is in the water?

*October 26, 2014*

**Math**

An urn contains 3 red, 4 orange, and 6 yellow marbles. 2 marbles are selected without replacement. Find the probability that the second marble selected is orange given that the first marble selected is yellow.

*October 13, 2014*

**Chemistry**

Molecular, ionic, and net ionic equations for ammonium chloride + potassium sulfate. Also what is the observation. Is it 2NH2Cl + Na2SO4 = (NH4)2SO4 + 2NaCl???? Please help!

*October 13, 2014*

**sociology**

Micah is studying child behavior in playgrounds throughout the world. He wants to see how the children react when teachers select the same child to be the first to use each piece of equipment. Which approach is Micah is using?

*October 8, 2014*

**chemistry**

A 22.0 g piece of alloy at 264.8°C is dropped into a simple calorimeter that contains 175.0 g of water. The temperature of the calorimeter water increased from 20.4°C to 23.1°C. Calculate the specific heat capacity of the alloy.

*October 6, 2014*

**math**

Solve the proportion for u. (u−2) : (u+3) = 4 : 3

*October 6, 2014*

**English check answers please!!**

"The King of Mazy May" by Jack London Which detail helps you predict that Walt will face a series of unfortunate events? a) Lifting clear on the crest of a great jam off Indian River, Walt masters met with his first accident b) The poor brute plunged in a heap, with ...

*October 4, 2014*

**algebra - check my answer?**

is my answer 119.75 square foot

*September 19, 2014*

**Science**

relative age

*September 15, 2014*

**Science**

how can you determine that a coin is not pure silver if you know the mass and volume of the coin?

*September 10, 2014*

**Math**

x^(log10x)=100 I'm not sure how to do this at all...

*August 25, 2014*

**Math**

An item is on sale for $12, which is at a discount of 20% off the original price. What is the original price? How do I do this without a calculator? Thank you !

*August 25, 2014*

**Economy Essay Outline/Structure Help**

I'm writing a synthesis paper about why we should utilize middle-out economics (basically economics that focus on the middle class) I'm very new to the topic so I don't want to spread myself too thin or dive into something I don't know too much about. I'm ...

*August 10, 2014*

**Science (Physics)**

Two resistors 3ohms and 6ohms are connected in parallel across a 6V battery, what is the current flow through the 3ohms resistors? Just the formula please.

*August 3, 2014*

**Essay Topic (Synthesis)**

Is the topic of Immigration Reform in the United States to controversial for my synthesis essay? I am writing a synthesis essay for my class, and it is a big portion of my grade. I have a lot of information about Immigration, but I'm afraid the topic will be too ...

*August 3, 2014*

**Physics **

A person of mass 50.0 kg is at the bottom of a cave. The cave has a depth of 32.5 meters and the person is to be pulled out of the cave vertically by a rope, starting from rest. What is the shortest amount of time that this could take if the rope can withstand a maximum ...

*May 14, 2014*

**Chemistry**

Im still confused.. is n 2? and if so would it look like this for A dHorxn=(2*2.84)-(2*-.227)??

*May 14, 2014*

**Math**

Solve (z +2)^ 4/3 = 4 where z is a real number please helpp

*May 14, 2014*

**Math **

Solve (z +2)^ 4/3 = 4 where z is a real number

*May 14, 2014*

**Chemistry ASAP**

Using a table of standard electrode potentials (such as the one in your textbook), calculate the standard cell potential for a cell made by placing a zinc electrode in a Zn2+(aq) solution which is connected by an electrolyte to a Ag+ (aq) solution containing a silver electrode...

*May 13, 2014*

**Science**

number 3 is correct.

*May 13, 2014*

**Physics **

A box of mass 1.50 kg is given an initial velocity of 12.5 m/s up an inclined ramp that makes an angle of 25.0o with the ground, which is horizontal. The coefficient of kinetic friction between the box and the ramp is 0.240. How long does the box slide up the ramp before it ...

*May 13, 2014*

**accounting**

In recent years, there has been a lot of media coverage about the funding status of pension plans for state employees. In many states, the amount of money invested in employee pension plans is far less than the amount estimated to be needed to pay them the retirement benefits ...

*May 6, 2014*

**Chemistry**

there is a graph yes, but it's confusing

*April 28, 2014*

**Chemistry**

A saturated solution of magnesium iodate has a temperature of 50°C. it contains 175g of dissolved solute. What is the volume of the solution?

*April 28, 2014*

**Chemistry**

At what temperature (∘C) will xenon atoms have the same average speed that Cl2 molecules have at 35∘C?

*April 27, 2014*

**Chemistry**

Methane gas, CH4, is sold in a 43.0L cylinder containing 5.91kg .What is the pressure inside the cylinder (in kilopascals) at 21∘C?

*April 27, 2014*

**Chemistry**

Traffic on the German autobahns reaches speeds of up to 230 km/h.At what temperature (∘C) do oxygen molecules have this same average speed?

*April 27, 2014*

**Chemistry**

What is the molecular mass of a gas that diffuses through a porous membrane 1.86 times faster than Xe?

*April 27, 2014*

**Chemistry**

An unknown gas is placed in a 1.500 L bulb at a pressure of 356 mm Hg and a temperature of 22.5 ∘C, and is found to weigh 0.8108g .What is the molecular mass of the gas?

*April 27, 2014*

**Chemistry**

A small cylinder of helium gas used for filling balloons has a volume of 2.85L and a pressure of 13300kPa at 25 ∘C.How many balloons can you fill if each one has a volume of 1.50L and a pressure of 1.26atm at 25 ∘C?

*April 27, 2014*

**Chemistry**

Oxygen gas is commonly sold in 48.0L steel containers at a pressure of 130atm .What volume (in liters) would the gas occupy if its temperature was raised from 20.5∘C to 40.0∘C at constant 130atm ?

*April 27, 2014*

**Physics **

An airplane needs to fly due south. The plane can fly at a speed of 720.0 km/hr in still air. If there is a wind blowing to the northeast at 70.0 km/hr, in what direction should the plane fly to maintain its heading of due south? How long will it take to fly a 1500.0 km distance?

*April 21, 2014*

**chemistry urgent**

NH4NO3(s)+H2O(l)→NH4NO3(aq) ΔH = +25.7 kJ. What is the final temperature in a squeezed cold pack that contains 45.5g of NH4NO3 dissolved in 125 mL of water? Assume a specific heat of 4.18J/(g⋅∘C) for the solution, an initial temperature of 29.0∘C, ...

*April 20, 2014*

**Chemistry**

Calculate ΔH∘f (in kilojoules per mole) for benzene, C6H6, from the following data: 2C6H6(l)+15O2(g)→12CO2(g)+6H2O(l) ΔH∘ = -6534kJ ΔH∘f (CO2) = -393.5kJ/mol ΔH∘f (H2O) = - 285.8kJ/mol

*April 20, 2014*

**Chemistry**

Assuming that the specific heat of the solution is 4.18 J/(g⋅∘C) and that the calorimeter itself absorbs a negligible amount of heat, calculate ΔH in kilojoules for the reaction CaO(s)+H2O(l)→Ca(OH)2(aq) When 1.045 g of CaO is added to 50.0 mL of water ...

*April 20, 2014*

**Math**

Can someone please work out the steps in solving this elimination problem. Thank you. The problem is x + 2y = -7 x - 5y = 7

*April 17, 2014*

**social studies**

What were the results of the Korean War? What impact did it have on American society?

*April 17, 2014*

**Math**

Solve by elimination x + 2y = -7 x - 5y = 7

*April 17, 2014*

**Math/Physics **

John is driving at a constant speed of 20.0 m/s when he passes Jane, who is traveling in the same direction at 15.0 m/s at the moment that John passes her. If Jane is accelerating at 2.0 m/s2, how far will Jane drive before she catches up to John? How much time passes from ...

*April 15, 2014*

**Physics **

A crate begins sliding down a frictionless incline of 25.0o. If the objects begins sliding from rest and takes 1.50 sec to slide down the incline, what is the speed of the crate as it leaves the incline? How long is the incline?

*April 15, 2014*

**Physics**

John is driving at a constant speed of 20.0 m/s when he passes Jane, who is traveling in the same direction at 15.0 m/s at the moment that John passes her. If Jane is accelerating at 2.0 m/s2, how far will Jane drive before she catches up to John? How much time passes from ...

*April 15, 2014*

**Physics **

Draw each of the following vectors on graph paper, then find the x- and y- components. Make sure to include units in your answers for the components. a) ⃑r = (65 m, 30degrees above the positive x-axis) b) ⃑v = (125 m/s, 40degrees below the negative x-axis) c) &#...

*April 7, 2014*

**Calculus**

negative one third t minus 1

*April 7, 2014*

**Calculus**

Two full 48-gallon tanks begin draining at t = 0. Tank Alpha's volume is changing at a constant rate of -16/5 gal/min. The rate at which Tank Bravo's volume is changing is given by r(t)=-1/3t-1 gal/min. a) How much water is in each tank after 5 minutes? b) Which tub ...

*April 7, 2014*

**Physics**

A cubic meter of some material has a mass of 6400 kg. The block of material is lowered into a lake by a strong cable until the block is completely submerged. Draw a free-body diagram for the block. (Do this on paper. Your instructor may ask you to turn in your work.) Find the ...

*March 31, 2014*

**science**

30 cubic meters of argon gas are kept under constant pressure. The gas is heated from 10.0 degrees Celsius to 293 degrees Celsius. What is the new volume of the gas?

*March 18, 2014*

**physics**

A DC circuit has a single battery of voltage V = 10.0 V attached to a resistor R = 100 Ohms. If the voltage is increased to 20.0 V, then by what factor does the power emitted by the resistor increase?

*March 5, 2014*

**Physics**

A 2 kg ball is rolled down a hill 25 m tall. When it reaches the bottom of the hill it is traveling at 15.1 m/s. How much energy was dissipated due to friction?

*March 4, 2014*

**physics**

an unpolarised light is incident on the boundary between two transparent media. State the contition when the reflected wave is totally plane polarised.

*March 3, 2014*

**Physics**

It takes 56 J to push a block 4 m. If the force is in the same direction as the displacement, what is the force on the block?

*March 3, 2014*

**Math**

It's just a notion

*February 21, 2014*

**English**

Presents I think

*February 19, 2014*

**Please Help with 2 Physics Problems???**

1) In a two-dimensional tug-of-war, Alex, Betty, and Charles pull horizontally on an automobile tire at the angles shown in the picture. The tire remains stationary in spite of the three pulls. Alex pulls with force FA of magnitude 207 N, and Charles pulls with force FC of ...

*February 17, 2014*

**Math**

Thank you Reiny

*February 16, 2014*

**Math**

Can someone help me to solve this scientific notation equation. (5.7 x 10^3)^-^4

*February 16, 2014*

**Physics**

A car accelerates from 12m/s to 25m/s in 6.0s. What is its uniform acceleration? How far did it travel in this time?

*February 11, 2014*

**Physics**

A plane flies 407 km east from city A to city B in 44.0 min and then 871 km south from city B to city C in 1.90 h. For the total trip, what are the (a) magnitude (in km) and (b) direction of the plane's displacement, the (c) magnitude (in km/h) and (d) direction of its ...

*February 10, 2014*

**Statistics**

Determine if the following are probability distributions (if no, state why). a. X 3 6 9 12 15 P(X) 4/9 2/9 1/9 1/9 1/9

*February 7, 2014*

**algebraic expressions**

write a situation that can be represented by the algebraic expression 3.25d

*February 6, 2014*

**History8**

Answer what

*February 3, 2014*

**Statistics**

What does the empirical rule say about the proportion of players who are between 62.7 inches and 75.3 inches? c.

*February 2, 2014*

**Pre-Algebra**

The treasurer of the student body at a college reported that the receipts from a recent contact totaled $916; Furthermore, he announced that 560 people had attended the concert. Students were charged $1.25 each for admission to the concert, and adults were charged $2.25 each. ...

*February 1, 2014*

**Science**

which of the following do rain forests and taiga have an common? A. similar average annual rainfalls. B. similar average annual temperature C. heavily populated with trees. D. tend to occur in similar latitudes

*January 30, 2014*

**Math**

Yes

*January 25, 2014*

**Math**

Snooki has a total of 25 quarters and pennies in her pocket. She has $2.32 altogether. How many quarters and pennies were sold?

*January 25, 2014*

**Astoria Park**

1+2+3+6 then 1+2=3 then 3+3=6 final answer 6+6 = 12 as the next perfect number

*January 15, 2014*

**World History ;-;**

Which of the following was a result of the development of Christianity in the Byzantine empire?

*January 13, 2014*

**Stats**

Suppose the following data are selected randomly from a population of normally distributed values. 42 51 43 48 41 57 54 39 45 48 45 39 46 Construct a 95% confidence interval to estimate the population mean. Round the intermediate values to 2 decimal places. Round your answers ...

*December 19, 2013*

**science**

Cbac are the right answers just took the test and got a 100%

*December 11, 2013*

**Chemistry**

1) A dog has the same mass for 3 years. State whether this represents an equilibrium or steady state situations, and give your reasons. I'm not sure if I got this question right... I think this is a steady state because the dog is opened to the environment where oxygen is ...

*November 25, 2013*

**math ms sue please help, PLEASE!!!!**

c & d

*November 13, 2013*

**Chemistry**

For the reaction Zn(OH)2(s)+4CN-(aq)->Zn(CN)4 2-(aq)+2OH-(aq) find [CN-] when 8.5 g of Zn(OH)2 are dissolved in 1.00 L of solution.

*November 10, 2013*

**math help plzzzz!!!!**

5 is wrong

*October 30, 2013*

**physics**

a .150kg object tied to a string is whirled in a horizontal circle ata constant angular speed of 3.50 revolutions per second. the tension is the string is 75newtons. what is the length of the string?

*October 27, 2013*

**Math**

Nooooooooooob

*October 23, 2013*

**Algebra**

I would be happy to inform you that t=23

*October 21, 2013*

**Can someone check these answer for me?**

1. B 2.B 3.D 4.D 5.A

*October 17, 2013*

**Can someone check these answer for me?**

is someone on

*October 17, 2013*

**science help plzzz**

PLEASE HELP

*October 17, 2013*

**science help plzzz**

1. A 2.D 3.B 4.C 5.B

*October 17, 2013*

**Chemistry**

yellow

*October 10, 2013*

**Physics**

A "swing" ride at a carnival consists of chairs that are swung in a circle by 19.8 m cables attached to a vertical rotating pole, as the drawing shows. Suppose the total mass of a chair and its occupant is 144 kg. (a) Determine the tension in the cable attached to ...

*October 3, 2013*

**Physics**

At an amusement park there is a ride in which cylindrically shaped chambers spin around a central axis. People sit in seats facing the axis, their backs against the outer wall. At one instant the outer wall moves at a speed of 3.44 m/s, and an 64.3-kg person feels a 277-N ...

*October 3, 2013*

**Physics**

A centrifuge is a device in which a small container of material is rotated at a high speed on a circular path. Such a device is used in medical laboratories, for instance, to cause the more dense red blood cells to settle through the less dense blood serum and collect at the ...

*October 3, 2013*

**chemistry**

Calculate the number of hydrogen molecules formed when 5.6 mL of ammonia at STP is decomposed by the following reaction: ___NH3 „³ ___ N2 + ___ H2

*September 25, 2013*

**chemistry**

Calculate the volume of oxygen at STP required to burn 3.7 kg C3H6O2 producing CO2 & H2O:

*September 25, 2013*

**SAT prep math **

Maria has two piggy banks. In one piggy bank she saves dimes and in the other she saves nickels. At the end of each month she saves 40 nickels and 30 dimes

*September 18, 2013*

**Physical Science**

a student is given a 10 gram sample of gold that has a density of 19.32g/cm3. The student is then given a 5 gram sample of an unknown substance and told the density of the unknown substance is 19.32g/cm3. What is the unknown substance

*September 10, 2013*

**Social Studies**

What is the answer

*September 10, 2013*

**chemistry**

determine the mass of CO2 produced when 51.2 g of CaO is reacted with 50.0 g of C according to the unbalanced equation CaO + C --------CaC2 =CO2

*August 26, 2013*

**chemistry**

in the reaction of magnesium metal with hydrochloric acid to produce magnesium chloride and hydrogen gas. If 4.59 mol of magnesium and 4.59 mol of hydrochloric acid are reacted, how many moles of magnesium chloride are produced ?

*August 26, 2013*

**science**

42.27m/s

*July 26, 2013*

**Please Help with calculus**

How to evaluate x=0 and dx=-.03? I got(1/9)e^(x/9)dx as dy of e^(x/9)and I don't know how I should plug them in.

*June 26, 2013*

**Calculus**

Let y=e^(x/9). a) Find the differential dy. dy = b) Evaluate dy if x=0 and dx=−0.03. dy =

*June 26, 2013*