Saturday

June 25, 2016
Total # Posts: 2,106

**Chemistry**

Write a balanced chemical equation (molecular equation). Write a total ionic equation. write a net ionic equation. (NH4)2 SO4(aq)+Na2CO3(aq) -->
*March 15, 2011*

**Hot-air balloon**

A hot-air balloon is 180 ft above the ground when a motorcycle passes directly beneath it (travelling in a straight line on a horizontal road) going at a constant speed of 60 ft/s. If the balloon is rising vertically at a rate of 15 ft/s, what is the rate of change of the ...
*March 15, 2011*

**maths**

thank you
*March 15, 2011*

**maths**

what is the circumference the radius the arc the chord the diameter
*March 15, 2011*

**Calculus **

A hot-air balloon is 180 ft above the ground when a motorcycle passes directly beneath it (travelling in a straight line on a horizontal road) going at a constant speed of 60 ft/s. If the balloon is rising vertically at a rate of 15 ft/s, what is the rate of change of the ...
*March 15, 2011*

**Social**

Key difference/s between the 1929 Crash and previous stockmarket crashes was/were A) The impact of the investor's pools B) That many middle income people were stockholders C) All of the choices D) The government's intervention I think it's all of the choices, but I...
*March 12, 2011*

**math**

matt used centimeter cubes to make a solid that had a volume of 5 cubic centimeters and a surface area of 22 square centimeters. what might his solid looked like?
*March 12, 2011*

**math**

3/4 x 5/7, but that means you presume you took out a blue marble the first time. How do you know that you didn't take out a red marble, so you still have all six blue marbles when you pick the second time?
*March 12, 2011*

**math**

If there are 6 blue marbles and 2 red marbles in a bag, what is the probability of picking a blue marble then another blue marble if you do not replace the first marble P(B,B)? 3/4 x 5/7 or is it 3/4 x 6/7?
*March 12, 2011*

**Math**

x/(x^2-16)-6/(x^2+5x+4)
*March 8, 2011*

**geometry**

Circle O above has a circumference of 240 cm and arc XW has a length of 60 cm. What is the measure of the central angle associated with arc XW?
*March 6, 2011*

**Economics**

As the aggregate price level falls, the number of domestic products purchased by foreigners will [rise], causing the quantity of domestic output demanded to [rise]. This is known as the [foreign purchases effect]. The first two blanks can be rise,fall or stay the same. and the...
*March 6, 2011*

**Chemistry**

If 15.0ml of a 6.0M HCl solution is diluted to 75.00ml, what is the molarity of the diluted solution?
*March 5, 2011*

**Physics **

For the reaction: C4H10 + O2 ¨ CO2 + H2O ( is this balanced?) , how many moles of CO2 is formed when 5.00 moles C4H10 reacts with O2? A. 5.00 B. 1.25 C. 20.0
*March 5, 2011*

**chemistery**

suppose that "element a" has a valence number of 3 and "element b" has a valence number of 2. if the two elements combine, then when writing the formula for the resulting compound what subscript number will be given to "element b"?
*March 4, 2011*

**Chemistry**

If i titrated 25.0mL of 0.500M HCl with 0.500M NaOH and then 25.0mL of 0.500M of an unknown weak acid HA with 0.500M NaOH. How would the two titration curves compare at 10 or 15mL of NaOH Beyond equivelance pts? I think that they will be the ssame or similar but i don't ...
*March 3, 2011*

**Chemistry**

I don't know how to get the mole ratios of the following: Copper to Chloride Zinc to Chloride Zinc to Copper There are the moles I have of each; Copper 4.25*10^-3 mol Zinc 3.67*10^-3 mol Chloride 2.27*10^-2 mol
*March 2, 2011*

**Chemistry (Stoichiometry)**

a) Mg + 2H2O ==> Mg(OH)2 + H2
*March 2, 2011*

**biology**

So is there an error in the book?
*March 1, 2011*

**biology**

A question in Campbell's 8th edition study guide for AP Biology says: A multifactorial disorder _. Answer: has a collection of symptoms traceable to an epistatic gene. There is another answer choice which says : has both genetic and environmental causes. Shouldn't the ...
*March 1, 2011*

**Chem**

If you prepared a solution by adding 0.05mL (1drop) of 0.5M HCL to 5 x 10^7 mL of "pure" water. Calc the resultant PH. The answer isn't ph= 9.3. you have to add all the hydronium ions from all sources... but how ?
*March 1, 2011*

**Chemistry**

A 0.250-g sample of a magnesium-aluminum alloy dissolves completely in an excess of HCl (aq) . When the liberated H2 (g) is collected over water at 29 degrees celsius and 752 torr, the volume is found to be 301 mL . The vapor pressure of water at 29 degrees celsius is 30.0 ...
*February 28, 2011*

**Calculus AB**

Solve the differential equation: dy/dx= (x^2+y^2)/(2xy) I know how to solve this type of problem, but I am struggling getting all of the x's and y's on different sides of the equation. Thank you for your help.
*February 28, 2011*

**Calculus AB**

Sorry I know this should be easy, but what is the integral of U/du?
*February 28, 2011*

**Calculus AB**

Please find the integral for: (2^(-1/t))/(t^2) Thank you very much
*February 28, 2011*

**Calculus AB**

Find the indefinite Integral of: (e^(2x)-e^(-2x))/(e^(2x)+e^(-2x))dx Thank you very much for your help.
*February 27, 2011*

**calculus**

Find the derivative of the inverse for the function f and real number a. f(x)=xrad(x-3) a=4 Please help. Thank you very much for your time and assistance.
*February 27, 2011*

**southuniversity**

You have been hired as the marketing manager. Research and identify major approaches of how innovations like these are adopted by consumers. Discuss how the marketing strategy for the car needs to rapidly move through these processes. Who or what are the key groups that need ...
*February 25, 2011*

**Chemistry**

A piece of dry ice (solid carbon dioxide) with a mass of 25.5 g is allowed to sublime (convert from solid to gas) into a large balloon. Assuming that all of the carbon dioxide ends up in the balloon, what will be the volume of the balloon at a temperature of 18 degrees Celsius...
*February 24, 2011*

**Chemistry**

A piece of dry ice (solid carbon dioxide) with a mass of 25.5 g is allowed to sublime (convert from solid to gas) into a large balloon. Assuming that all of the carbon dioxide ends up in the balloon, what will be the volume of the balloon at a temperature of 18 degrees Celsius...
*February 24, 2011*

**Physics**

A block rides on a piston that is moving vertically with simple harmonic motion. (a) If the SHM has period 3.1 s, at what amplitude of motion will the block and piston separate? (b) If the piston has an amplitude of 9.6 cm, what is the maximum frequency for which the block and...
*February 22, 2011*

**Math**

161.8
*February 22, 2011*

**government**

Students are to read up on the role of Hezbollah as a political force in Lebanon. Due to Lebanon's geographical position, economy, and politics, would an Egyptian style revolution beneficial or detrimental to the US government? Acting as the president's Security ...
*February 22, 2011*

**chemistry**

A particular kind of emergency breathing apparatus-often placed in mines, caves, or other places where oxygen might become depleted or where the air might become poisoned-works via the following chemical reaction: 4KO2(s)+2CO2(g)--> 2K2CO3(s)+3O2(g) Notice that the reaction...
*February 21, 2011*

**chemistry**

A particular kind of emergency breathing apparatus-often placed in mines, caves, or other places where oxygen might become depleted or where the air might become poisoned-works via the following chemical reaction: 4KO2(s)+2CO2(g)--> 2K2CO3(s)+3O2(g) Notice that the reaction...
*February 21, 2011*

**Chemistry**

What is the Cl concentration just as Ag2CrO4 begins to precipitate when 1.0 M AgNO3 is slowly added to a solution containing 0.015 M Cl and 0.015 M CrO4^2?
*February 20, 2011*

**organic chemistry**

Im working on a lab dealing with NRM of C3H8O2. carbons are 57.5 (q) , 60.1 (t), and 73.1 (t) i forget how to find the basic structure.
*February 19, 2011*

**physics**

Two cars are traveling in opposite directions on a two lane road. Car A starts from the origin at t =0 and accelerates (moving due East) from rest at 4 m/s2. At t = 0, Car B is moving due West with a velocity of 15 m/s and is 500 m east of car A but accelerating toward the ...
*February 16, 2011*

**physics**

A pendulum clock has a heavy bob supported on a very thin steel rod that is 1.00000 m long at 18.0celcius. 1 - what is the clock's period if the temperature increases by 11.0 celcius? Assume that coefficient of linear expansion of steel is 1.20×10−5K ^-1 . 2 - ...
*February 11, 2011*

**pre- algebra**

1=3^-2 x 3^x
*February 10, 2011*

**maths**

if the diameter of a bike wheel is 20cm, what's the minimum number of revolutions needed to cover 1km?
*February 6, 2011*

**chemistry**

How do you find the rate(mole rxn/L s) from .00014 M or Iodine, .57 M or acetone, and .18 M of H+ and 16.8 seconds?
*February 2, 2011*

**math**

A man is 6ft tall is standing 10 feet from the base of a lamp post. The mans shadow has a lenght of 4ft . How tal is he lamp post
*January 31, 2011*

**Physics**

A dockworker applies a constant horizontal force of 79.0 N to a block of ice on a smooth horizontal floor. The frictional force is negligible. The block starts from rest and moves a distance 13.0 m in a time 4.50 s. What is the mass of the block of ice?If the worker stops ...
*January 31, 2011*

**Physics**

A dockworker applies a constant horizontal force of 79.0 N to a block of ice on a smooth horizontal floor. The frictional force is negligible. The block starts from rest and moves a distance 13.0 m in a time 4.50 s. What is the mass of the block of ice?If the worker stops ...
*January 31, 2011*

**grammer**

find the predicate nominative or predicate adjective. The photos throughout the book look fascinating.
*January 25, 2011*

**Math (Calculus AB)**

If y=cos^2x-sin^2x, then y'= a) -1 b) 0 c) -2(cosx+sinx) d) 2(cosx+sinx) e) -4(cosx)(sinx) I thought the answer was C but the answer key says it is E. Please help. Thanks in advance.
*January 24, 2011*

**Math (Calculus AB)**

An equation to the graph of y=x^3+3x^2+2 at its point of inflection is: a) y=-3x+1 b)y=-3x-7 c)y=x+5 d)y=3x+1 e)y=3x+7 Please help. I am in urgent need.
*January 24, 2011*

**Math (Calculus AB)**

For x≠0, the slope of the tangent to y=xcosx equals zero whenever: (a) tanx=-x (b) tanx=1/x (c) sinx=x (d) cosx=x Please help. I have a final tomorrow and I am working diligently to understand every type of problem that may show up on my test. Thank you very much.
*January 24, 2011*

**Math (Calculus AB)**

For x≠0, the slope of the tangent to y=xcosx equals zero whenever: (a) tanx=-x (b) tanx=1/x (c) sinx=x (d) cosx=x Please help. I have a final tomorrow and I am working diligently to understand every type of problem that may show up on my test. Thank you very much.
*January 24, 2011*

**Physics**

that is easy actually..... d(distance)= 1/2at^2 +v(initial)t, where a-acceleration, t-time. v-initial here is 0 because the car starts from rest....so d= 1/2at^2 which is .5(3.5)(3.6^2)...which comes out to 22.68m I believe
*January 24, 2011*

**reading**

What's the question then? It doesn't say the question, how are we supposed to help?
*January 22, 2011*

**Math**

Find the value of the constant t such that the triangle formed by A (2,2) ,B (4,-5) ,C (6,t) is right angled at B(4,-5).
*January 21, 2011*

**english**

take the first definiton then double the consanant you idiot
*January 19, 2011*

**physics**

a 2kg mallet is dropped from a height of .6m onto a nail, driving it 3.5 cm into the wood. What is the average force exerted by the mallet on the nail? thanks
*January 19, 2011*

**geometry**

In triangle abc, ab=5 bc=9 and ac=8 Choose the angle measures from greatest to least
*January 19, 2011*

**math**

Camilla has 3 times as many points as Lynn. Lynn has 5 more points than Kim. Camilla, Lynn, and Kim combined have twice as many points as Jasmine. If Jasmine has 25 points - how many points do the three other girls have?
*January 17, 2011*

**Social Studies**

how did helen thomas feel about watergate? if u could also tell me where u found the answer that would help, thanks
*January 17, 2011*

**Nuclear Physics**

If a polonium-210 (Po-210) atom has just decayed, how close can the ejected alpha particle get to a neighboring Po-210 nucleus? Hint: W = F*r F=kq1q2/r2
*January 16, 2011*

**chemistry**

I got E) for the first and couldn't figure out the other one. Can any one verify the first and help with the second?? In which of the following processes is there a decrease in the potential energy of the substances involved? A) a coil spring is compressed B) two ...
*January 13, 2011*

**chemistry**

I got E) for the first and couldn't figure out the other one. Can any one verify the first and help with the second?? In which of the following processes is there a decrease in the potential energy of the substances involved? A) a coil spring is compressed B) two particles...
*January 13, 2011*

**algebra**

Tom's mother pays him $.50 for each problem his gets correct on his test, but he has to give her .25 for each problem he gets wrong. If Tom makes $8.00 on the test, and there were 25 total problems on the test, how many did he answer correctly? Thanks!
*January 11, 2011*

**physics**

How much potential energy does a 20-kg barrel have when it is in the truck whose floor is 5.0 m above the ground?
*January 7, 2011*

**Geometry**

In right triangle ABC, the median to the hypotenuse has length 15 units and the altitude to the hypotenuse has length 12 units. What is the legth of the shorter leg of triangle ABC?
*January 6, 2011*

**science**

based on the relationship between mass and volume.... How much space would 75 grams of water occupy?
*January 6, 2011*

**chemistry**

suppose you have an unknown gas, and wish to determine whether it may be ammonia, hydrogen or carbon dioxide. Describe tests you might use to prove the existence of each of these gases.
*December 16, 2010*

**Physics**

A train sounds its horn as it approaches an intersection. The horn can just be heard at a level of 42 dB by an observer 10 km away. (a) What is the average power generated by the horn? W (b) What intensity level of the horn's sound is observed by someone waiting at an ...
*December 13, 2010*

**chemistry**

what is the wavelength of an electron traveling at 1.65% of the speed of light?
*December 10, 2010*

**8th grade**

An alloy of metals is 25% copper .Another alloy is 50% copper. How much of each alloy should be used to make 1000grams of an alloy that is 45% copper?
*December 9, 2010*

**chemistry**

The strongest intermolecular forces present in a sample of pure I2 are A. covalent bonds. B. covalent network bonds. C. metallic bonds. D. dipole–dipole forces. E. London forces.
*December 9, 2010*

**Geometry **

Given:JG/HG =KG/IG, ∠1 ≅∠2 Prove: EF ll HI /Users/szeringue/Documents/#6.doc
*December 9, 2010*

**Chemistry**

The normal boiling point of a liquid is A. the temperature at which all three phases are in equilibrium. B. the only temperature at which there can be equilibrium between the liquid and gas states. C. the temperature at which the vapor pressure equals 760 mmHg. D. the ...
*December 9, 2010*

**Chemistry**

All of the following are postulates of the kinetic molecular theory of gases except A. The gas molecules are in constant motion. B. The gas molecules are in rapid motion. C. The collisions between molecules are elastic. D. At a constant temperature, each molecule has the same ...
*December 9, 2010*

**Chemistry**

Which of the following compounds has the highest vapor pressure at 25°C? A. CH3CH2OH B. CH3OCH3 C. CH3CH2CH2Cl D. CH3CH2CH3 E. CH3CH2CH2CH
*December 9, 2010*

**GenChemistry**

Exposure to high doses of microwaves can cause tissue damage. Estimate how many photons with a wavelength = 12cm, must be absorbed to raise the temperature of your eye by 3.0 deg C. Assume the mass of the eye is 11g and its specific heat is 4.0 J/gK
*December 8, 2010*

**Chemistry**

CaO(s) + 3C(s) > CaC2(s) + CO(g) deltaHrxn = +464.8 kJ/mol-rxn Is the reaction endothermic or exothermic? What is the enthalpy change if 10.0 g of CaO is allowed to react with an excess of carbon?
*December 8, 2010*

**Physics**

The A string of a violin is 31 cm long between fixed points with a fundamental frequency of 440 Hz and a mass per unit length of 5.8×10^−4 kg/m. What are the wave speed in the string? What are the tension in the string? What is the length of the tube of a simple ...
*December 7, 2010*

**Chemistry**

Write a nuclear equation for the following: Iodine 131 undergoes beta decay two times Plutonium 239 is an alpha emitter Th 234 undergoes beta decay once and then alpha decay How do I go about writing nuclear equations?
*December 6, 2010*

**Chemistry**

Calculate the energy changes associated with each of the following reactions. Label each as endothermic or exothermic. A.) 2(C2H2)+5(O2)------->4(CO2)+2(H2O) B.) N2+O2------>2(NO) C.) NH3+H2O----->NH4OH D.) 2(BrCl)----->Br2+Cl2
*December 6, 2010*

**algebra**

K*T=K*T I need help solving for T. How would I do it?
*December 5, 2010*

**algebra**

K*T=K*T How would I solve for T?
*December 5, 2010*

**10th grade**

how do you calculate the volume of the aluminum block from the apparent change in the volume of water in the cylinder?
*December 3, 2010*

**Physics**

The intensity of an earthquake wave passing through the Earth is measured to be 2.5×106 J/m^2 at a distance of 48 km from the source. What was its intensity when it passed a point only 2.0 km from the source? At what rate did energy pass through an area of 3.0 m^2 at 2.0...
*December 2, 2010*

**Geometry Please Help**

/Users/szeringue/Desktop/SCAN0001.JPG Can you help me solve this problem, Please AB=27 BC=x CD=4/3x AD=x AC=? How do I get what AC equals?
*December 2, 2010*

**Geometry Please Help**

/Users/szeringue/Desktop/SCAN0001.JPG Can you help me solve this problem, Please AB=27 BC=x CD=4/3x AD=x AC=? How do I get what AC equals?
*December 2, 2010*

**Geometry**

/Users/szeringue/Desktop/SCAN0001.JPG Can you help me solve this problem, Please AB=27 BC=x CD=4/3x AD=x AC=? How do I get what AC equals?
*December 2, 2010*

**Geometry**

/Users/szeringue/Desktop/SCAN0001.JPG Can you help me solve this problem, Please AB=27 BC=x CD=4/3x AD=x AC=? How do I get what AC equals?
*December 2, 2010*

**chemistry**

One reaction of iron with hydrochloric acid is represented by the following thermochemical equation. Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g); ΔH°= –87.9 kJ How much heat is liberated at constant pressure if 0.416 g of iron reacts with 42.0 mL of 0.457 M HCl?
*December 2, 2010*

**college chemistry**

Consider the following metals. Metal Specific Heat copper 0.385 J/(g · °C) magnesium 1.02 J/(g · °C) mercury 0.138 J/(g · °C) silver 0.237 J/(g · °C) lead 0.129 J/(g · °C) If the same amount of heat is added to 25.0 g of ...
*December 2, 2010*

**chemistry**

From the following information, determine ΔH°f of malonic acid, CH2(COOH)2(s). CH2(COOH)2(s) + 2O2(g) → 3CO2(g) + 2H2O(l); ΔH° = –861.0 kJ Substance ΔH°f (kJ/mol) CO2(g) –393.5 H2O(l) –285.8 A. 2613.1 kJ B. –1540.3 kJ C. &#...
*December 2, 2010*

**English**

you're correct
*December 1, 2010*

**physical science**

what is non convective rain?
*December 1, 2010*

**math**

due to it's shape
*December 1, 2010*

**Algebra**

try using the quadradic formula!
*December 1, 2010*

**Chemistry**

Write the balanced equation and solubility product expression for the solubility equilibrium of Mn3(PO4)2: i thought the answer was Mn3(PO4)2 (s) = Mn^2+(aq) + (PO4)2 ^3- (aq) but thats not right. then for the Ksp expression i thought it was [Mn^2+] [PO4]^2
*December 1, 2010*

**Chemistry**

Write the balanced equation and solubility product expression for the solubility equilibrium of Mn3(PO4)2: i thought the answer was Mn3(PO4)2 (s) = Mn^2+(aq) + (PO4)2 ^3- (aq) but thats not right. then for the Ksp expression i thought it was [Mn^2+] [PO4]^2
*November 30, 2010*

**Math**

What is the inverse of f(x) = x^2 − 7, x ≤ 0
*November 30, 2010*

**chemistry**

The net ionic equations for the following 1. Dissolution of silver oxalate with nitric acid 2. Complexation of the iron(III) by the thiocyanate ion 3. Precipitation of the carbonate ion with barium ion 4. precipitation of the oxalate ion with barium ion 5. precipitation of the...
*November 30, 2010*

**Math**

for what values of _ is 2,3_1 divisible by 9? by 3?
*November 29, 2010*

**Physics**

asdfasdbas afba 2.4
*November 29, 2010*