Sunday

March 1, 2015

March 1, 2015

Total # Posts: 181

**Chemistry, HELP!**

Mole fractions
*February 26, 2015*

**Chemistry, HELP!**

Molybdenum (Mo) is a heavy metal that can have severe health effects on humans and animals. Tailings from a mining operation in Colorado have polluted surface waters used by grazing animals with Mo. Based on the following information determine the concentration of the three Mo...
*February 26, 2015*

**Math**

What is the unit rate of ounces. A hint is 48 ounces cost costs 3.00 dollars. I divided 48 by three but and got 16 cents but when I multiply by 48 it doesn't equal 3 dollars
*February 25, 2015*

**Math**

1. Daniel wants to save at least 20 dollars by putting pennies in a jar daily. On first day, he puts one penny into the jar. The second day he puts 2 pennies into the same jar. On the nth day he pus n pennies into the same jar. Which day is the first day on which he has at ...
*February 22, 2015*

**Chemistry AP**

1.301029996, thanks Bob
*February 20, 2015*

**Chemistry AP**

Hey Bob, What is the pH at the point during a titration when 20 mL of 0.200 M HCl has been added to 30 mL of 0.0500 M NH3 solution? HCl is strong acid, Kb = 1.8 × 10−5 for NH3. Answer in units of pH. I've gone about getting the mmol of HCl and NH3, getting ...
*February 20, 2015*

**Chemistry AP**

Remember the system I use for online homework does not care about significant digits, it goes out to /at least/ 6 decimal places. And I butchered spelling rearranging.
*February 9, 2015*

**Chemistry AP**

Alright, this time, I know I have not mistyped my answer. Find the initial concentration of the weak acid or base in an aqueous solution of hydrazine (NH2NH2) with a pH of 10.16. Kb = 1.70 ×10−6 Answer in M I've tried going from 10^-pH then using that (as my x...
*February 9, 2015*

**Chemistry AP**

Once again I was foolish and mistyped an earlier answer, getting 4.02e-4 for my answer. I had not put in the 0 between the 4 and the 2 when submitting.
*February 9, 2015*

**Chemistry AP**

Well, I've tried going using 4.3e-7=x^2/0.377 to get to what x equals, I've been getting 0.0069, but it's incorrect.
*February 9, 2015*

**Chemistry AP**

Calculate the concentration of H3O + present in 0.377 M H2CO3. Answer in units of mol/L I know the Ka of H2CO3 is 4.3E-7. But I don't know what to do from there. (Or, I'm not getting the correct answer at least)
*February 9, 2015*

**SS**

What was the purpose of the Adams-Onis Treaty? Can some help me answer this question?? Ms. Sue??
*February 6, 2015*

**Chemistry AP**

The UT (University of Texas) Quest system, Online quizzes, takes it out further for it to count as correct, when I am taking in class tests on paper, yes, it's cut down using significant digits.
*February 5, 2015*

**Chemistry AP**

I've figured out my mistake, mentioned above your post, mistypes when inputting answers are a terrible thing :p
*February 5, 2015*

**Chemistry AP**

I made a silly mistake and inputted the correct answer of 4.805909915 as 4,805909915, I noticed as I looked at my previous answers, sorry for all of this.
*February 5, 2015*

**Chemistry AP**

Calculate the pH of a 0.44 M aqueous solution of NH4Cl. Kb = 1.8 × 10−5 . I've tried used the Ka=Kw/Kb equation then used the resulting 5.5e-10 in Kw=([H+][Cl-])/[NH4Cl] , using that to get the [H+], but it isn't correct and I don't know what else to do...
*February 5, 2015*

**Chemistry AP**

Correction. I meant Ka=([H+][Cl-])/[NH4Cl] not Kw
*February 5, 2015*

**Chemistry AP**

Calculate the pH of a 0.44 M aqueous solution of NH4Cl. Kb = 1.8 × 10−5 . I've tried used the Ka=Kw/Kb equation then used the resulting 5.5e-10 in Kw=([H+][Cl-])/[NH4Cl] , using that to get the [H+], but it isn't correct and I don't know what else to do.
*February 5, 2015*

**AP Chemistry**

Calculate the entropy change when 4.88 g of H2 reacts with O2 according to the reaction 2H2(g) + O2(g)→2H2O(ℓ)at 298 K and 1 atm pressure. The standard molar enthalpy of formation of H2O(ℓ)at 298 K is −285.8 kJ/mol. The corresponding free energy of ...
*January 20, 2015*

**AP Chemistry**

What is the value of w (work) when 1.3 moles of H2 expands from 25 liters to 50 liters against a constant external pressure of 1 atm, then expands further from 50 to 100 liters against a constant external pressure of 0.1 atm? Answer in calories. Answer in units of cal I know ...
*January 6, 2015*

**physics**

Calculate the momentum of a 0.1 kg rifle bullet traveling 500 m/s. Answer in units of kg•m/s
*November 13, 2014*

**trigonometry**

A tent pole is 85 feet high. A cable is attached to the ground 200 feet from the tower base. How long is the cable? What is the measure of the angle the cable makes to the ground?
*May 26, 2014*

**physics**

Two stars are 4.40 1011 m apart and are equally distant from the earth. A telescope has an objective lens with a diameter of 1.03 m and just detects these stars as separate objects. Assume that light of wavelength 550 nm is being observed. Also assume that diffraction effects...
*April 18, 2014*

**Biology: Genetics**

In guinea pig, short hair (L) is dominant to long hair (l) and the heterozygous condition for yellow coat (Y) and white coat (y) gives cream coat. A short haired guinea pig is bred to long haired white guinea pig and one of the offspring is a long haired baby guinea pig. a. ...
*February 4, 2014*

**Calculus**

A spherical oil tank with a radius of 10 feet is half full of oil that weighs 60 pounds per cubic foot. Its top is 6 feet underground. How much work is needed to pump the oil out of the tank through a hole in its top? How do I solve this? Does the fact that it its top is 6 ...
*December 14, 2013*

**Calc**

I did the problem. I found the fluid force to be 54 times the integral from -3 to 0 of (-y)(2)(root(9-y^2)dy my final answer was 972 pounds. Is that correct? note from my work: h(y)=-y L(y)=2x=2root(9-y^2)
*December 14, 2013*

**Calc**

A cylindrical slime tank is placed so that the axis of the cylinder is horizontal. Find the fluid force on a circular end of the tank if the tank is half full, assuming that the diameter is 6 feet and the slime weighs 54 pounds per cubic feet?
*December 14, 2013*

**pre-algebra**

Can you help
*October 1, 2013*

**math**

How to tell 4/7 on a ruler
*May 13, 2013*

**math**

K Thanks
*May 13, 2013*

**math**

What is 4/7 in inches
*May 13, 2013*

**math**

How to tell 4/7 on a ruler
*May 13, 2013*

**math**

Thank you
*May 5, 2013*

**math**

What does 1/10 equal in percent?
*May 5, 2013*

**math**

Thank u :-)
*May 2, 2013*

**math**

Dave sent five emails every 6 minutes for 30 minutes. Lee sent 4 emails every 5 minutes for 30 minutes. Who sent more emails?
*May 2, 2013*

**math**

1)I AM greater than 15 and less than 40 if you double me I become a number that ends in 0 1/5 of me is equal to 5 2) if you multiply me by 2 ,I become a number greater than 20 and less than 40 if you multiply me by 6,I end in 8 if you multiply me by 4 I end in 2 Help me figure...
*April 11, 2013*

**Physics**

An object is dropped from rest. What is its instantaneous speed when it has been in motion for 7 s? The acceleration of gravity is 9.8 m/s 2 . Answer in units of m/s
*March 16, 2013*

**Chemistry**

In a 1.0× 10–4 M solution of HClO(aq), identify the relative molar amounts of these species from most to least: HClO, OCl, OH^-, H30^+, H20
*February 21, 2013*

**math**

how do I find the volume of a rectangular prism height 2 ft, width 5 1/2 ft length 9 3/8 ft?
*February 4, 2013*

**please help this is a geometry question**

is this for artofproblemsolving? I have the same question. Idk but I think it is close to 343√3/3π.
*December 5, 2012*

**Physics**

This is a projectile motion question. A ball with a mass of .4 kg, initially at rest is kicked directly toward a 3 meter fence from a point 20 meters away. The initial velocity is 17 m/s at an angle of 35 degrees. The ball is hit by nothing and there is no wind resistance, but...
*October 13, 2012*

**math**

Two investments earn a total annual income of $2825. One investment is in a 6.75% annual simple interest certificate of deposit. The other is in a 7.25% tax free annual simple interest account. The total amount invested is 40,000. Find the amount in invested in the certificate...
*October 3, 2012*

**math**

When i am rounded to the nearest tens I am 1,000. I am the same when read forward or backward, I can be two different numbers. Who am I?
*September 26, 2012*

**Geometry**

graph each set of lines to form a triangle. find the area and perimeter. y=2, x=5 , and y=x Answer is Area = 4.5 units Perimeter = 6 + square root of 2. I don't know how to graph this. What does y=x mean?
*July 4, 2012*

**Physics**

At a county fair, a boy takes his teddy bear on the giant Ferris wheel. Unfortunately, at the top of the ride, he accidentally drops his stuffed buddy. The wheel has a diameter of 14.6 m, the bottom of the wheel is 2.4 m above the ground and its rim is moving at a speed of 1.0...
*June 14, 2012*

**Integral Calculus**

Sorry, I misread that as 2x instead of x^2.
*May 24, 2012*

**Integral Calculus**

To solve that last integral, you have to use the substitution rule. u= x^2 + 1 du= 2x Therefore the integral becomes: -1/2∫(2/u) du Factor out the 2 -∫1/u du Integrate -ln(u) Which is equal to -ln(x^2 +1) Since u= x^2 + 1
*May 24, 2012*

**Physics**

I understand how the first and third equations are used to find the answers, but how is the second equation (mg = Tcosa) used?
*May 24, 2012*

**Physics**

An external force F is holding a bob of mass 725 g in a stationary position. The angle that the massless rope makes with the vertical is θ = 33°. (a) What is the magnitude, F, of the force needed to maintain equilibrium in N? (b) What is the tension in the rope in N?
*May 24, 2012*

**Advanced Algebra**

Jim begins a job with a starting salary of 27000 dollars. she is guaranteed a raise of 4.75% each year. Sarah also starts a job with a salary of 27000 dollars, she is guaranteed a raise of 1500 dollars each year. What will be Jim's salary after five years
*April 30, 2012*

**Chemistry**

Calculate the cell potential for this voltaic cell at 298K if it is constructed using solutions of .25M Ni(NO3)2 and .01M Cu(NO3)2 Any explanation would be spectacular
*April 23, 2012*

**Chemistry**

A voltaic cell utilizes the following reaction and operates at 298K 3Ce{4+}(aq)+Cr(s)--->3Ce{3+}(aq)+Cr{3+}(aq) {}=Charge What is the EMF of this cell under standard conditions? What is emf of cell when [Ce{4+}]=2.1M, [Ce{3+}]=.13M, and [Cr{3+}]=2.0*10^-2
*April 15, 2012*

**Chemistry**

A voltaic cell utilizes the following reaction and operates at 298K 3Ce{4+}(aq)+Cr(s)--->3Ce{3+}(aq)+Cr{3+}(aq) {}=Charge What is the EMF of this cell under standard conditions? What is emf of cell when [Ce{4+}]=2.1M, [Ce{3+}]=.13M, and [Cr{3+}]=2.0*10^-2
*April 15, 2012*

**Chemistry **

Consider the voltaic cell Zn(s) + Cu{2+}(aq)--> Zn{2+}(aq)+Cu(s) {}=charge Under standard conditions, what is the maximum electrical work, in Joules that can accomplish if 60 g of copper is plated out?
*April 15, 2012*

**Chemistry**

Cytochrome, a complicated molecule that we will represent as CyFe2+, reacts with the air we breathe to supply energy required to synthesize adenosine triphosphate (ATP). At pH 7.0 the following reduction potentials pertain to this oxidation of CyFe2+: O2(g) + 4 H+(aq) + 4 e...
*April 15, 2012*

**Chemistry**

Complete and balance the following equation: Cr2O7{2-}(aq)+CH3OH(aq)-->HCO2H(aq)+Cr{3+}(aq) Any feedback would be great, thank you so much.
*April 14, 2012*

**Physics**

A diver performing a double somersault spins at an angular speed of 4.5 π rad/s precisely 0.70s after leaving the platform. Assuming the diver begins with zero initial angular speed and accelerates at a constant rate, what is the diver’s angular acceleration during ...
*March 28, 2012*

**Physics**

A girl sitting on a merry-go-round moves counterclockwise through an arc length of 3.36m. If the girl’s angular displacement is 2.96 rad, how far is she from the center of the merry-go-round? Answer in units of m.
*March 28, 2012*

**Physics**

A ﬁgure skater begins spinning counterclockwise at an angular speed of 4.6π rad/s. During a 4.6s interval, she slowly pulls her arms inward and ﬁnally spins at 7.6π rad/s. What is her average angular acceleration during this time interval? Answer in ...
*March 28, 2012*

**Physics**

The tension in a string from which a 5.4kg object is suspended in an elevator is equal to 53.02N. What is magnitude of the acceleration a of the elevator? The acceleration of gravity is 9.8 m/s^2
*February 15, 2012*

**Physics**

A 40.7kg wagon is towed up a hill inclined at 18.1 degrees with respect to the horizontal. The tow rope is parallel to the incline and has a tension of 139N in it. Assume that the wagon starts from rest at the bottom of the hill, and neglect friction. The acceleration of ...
*February 15, 2012*

**Physics **

Karen has a mass of 62.60 kg and she rides the up escalator at Woodley Park Station of the Washington D.C. Metro. Karen rode a distance of 62 m, the longest escalator in the free world. How much work did the escalator do on Karen if it has an inclination of 35°?
*January 31, 2012*

**Physics **

An 845-N sled is pulled a distance of 190 m. The task requires 1.70 104 J of work and is done by pulling on a rope with a force of 124 N. At what angle is the rope held?
*January 31, 2012*

**Pre-Algrebra**

I(220-a-r)+r I=.5 a=45 r=85
*January 20, 2012*

**math**

Can you please give me a example of a - and + multi step equation
*January 19, 2012*

**math-probability**

There is a 10/49 chance that BOTH of them are running.
*December 13, 2011*

**math-probability**

Disregard my previous answer. You should add the probabilities. 7/7 chance.
*December 13, 2011*

**math-probability**

Multiply the two probabilities together. 2 5 10 - x - = -- 7 7 49 There is a 10/49 chance that AT LEAST one of them is running on a given day. I think.
*December 13, 2011*

**Algebra**

You actually need parentheses around '2200 + 1.50x' when you are dividing to find the average. So (2200 + 1.5x)/x would be my answer. (I removed the 0 after 1.5 also, as 1.5 is the same number as 1.50.)
*December 13, 2011*

**English/Commas**

I'm not sure, but I think that the first sentence needs another comma to separate the state from the city (if Winston is a city in Colorado). Also, in the first sentence, I think that John Pearson is the person living in Colorado, and not being addressed. Therefore, I don...
*December 13, 2011*

**geometry**

"I get another chance" is the hypothesis. "I will do better" is the conclusion.
*December 12, 2011*

**Calculus**

When a particle is located a distance x meters from the origin, a force of cos(x/4) newtons acts on it. How much work W is done in moving the particle from x = 1 to x = 3?
*December 4, 2011*

**Chemistry**

Thanks for the help!
*November 19, 2011*

**Chemistry**

Need a lot of help! Specific gravity of a drug is 0.9815. How many cc of this drug should be administered for a dose of 215mg?
*November 19, 2011*

**math**

In 69 games, a player blocks 234 shots, what is his blocks per ratio?
*November 17, 2011*

**Calculus**

The widths (in meters) of a kidney-shaped swimming pool were measured at 3-meter intervals as indicated in the figure. Use the Midpoint Rule with n = 4 to estimate the area S of the pool if a1 = 15.5, a2 = 18, a3 = 17, a4 = 14, a5 = 12.5, a6 = 12, and a7 = 12.
*November 9, 2011*

**Math**

Janice said that if you cut a cube into two parts you form 2 smaller cubes. Ling said that 2 rectangular prisms are formed. Who is correct? Explain.
*November 5, 2011*

**Math**

Expand [1+x^2(1+x)]^7 in ascending powers of x as the term in x^8.
*October 2, 2011*

**Please Help!!!**

given the graph of f(x) = x sinx, 0<=x<=2pi assuming that a quantity y changes at a rate of y' = xsinx, find by how much it will increase or decrease over 3pi/2 <= x <= 2pi
*September 28, 2011*

**calculus**

given the graph of f(x) = x sinx, 0<=x<=2pi assuming that a quantity y changes at a rate of y' = xsinx, find by how much it will increase or decrease over 3pi/2 <= x <= 2pi
*September 28, 2011*

**calculus**

given the graph of f(x) = x sinx, 0<=x<=2pi assuming that a quantity y changes at a rate of y' = xsinx, find by how much it will increase or decrease over 3pi/2 <= x <= 2pi the area under the graph from 0 to pi/2 is 1 the area under the graph from pi/2 to pi is...
*September 27, 2011*

**Geometry**

the measure of an angle is 7 less than 10 times its supplement
*September 27, 2011*

**chemistry**

350.ml of .25M KOH is reacted with 250.ml of .30M H3PO4. Determine which is the limiting reagent, the molarity of the salt formed, and the final molarity of the reactant that was in excess.
*September 26, 2011*

**Math**

insert grouping symbols into 2x3^3+4 to get it to equal 4374 and 279,936.
*August 23, 2011*

**math**

Ok idk haah post if u like this coment
*May 28, 2011*

**algebra**

(4a^3b^2-14a^2b-18ab^2)/(2ab)
*May 25, 2011*

**algebra**

(4a^3b^2-14a^2b-18ab^2)/(2ab)
*May 25, 2011*

**algebra**

(4a^3b^2-14a^2b-18ab^2)/(2ab)
*May 25, 2011*

**us history**

abrham lincoln as a young adult
*May 21, 2011*

**Calculus**

lim sin2x x->0 ----- x How do I get rid of the x on the bottom in order to solve this problem? Thanks!
*May 14, 2011*

**algebra**

A CAN'S DIAMETER IS 3 INCHES, AND IT HEIGHT IS 8 INCHES. WHAT IS THE VOLUME OF THE CAN.
*April 29, 2011*

**Math**

Use the product rule to find the derivative of (2x^2 + 3)(3x + 5).
*April 26, 2011*

**math/alg**

Use the product rule to find the derivative of (2x^2 + 3)(3x + 5).
*April 26, 2011*

**Math**

what is the rule of a table with x numbers of 1, 4, 8, and 9 and y numbers of 5, 14, 26, and 29
*April 12, 2011*

**physics**

How fast must a cetrifuge rotate in order for a particle 9cm from the axis of rotation to experience an acceleration of 115000g's
*February 20, 2011*

**Physics**

A chain is held on a frictionless table with 1/3 of its length hanging over the edge. If the chain has length L = 33 cm and mass m = 21 g, how much work is required to pull the hanging part back onto the table?
*February 16, 2011*

**math**

I am a number between 20 and 30.When you put me into 6 equal groups,there is an even number in each group and 1 left over. i cant figure out how to solve this
*February 16, 2011*

**MAth(Someone please help)**

What would the function H(x)=0.002x^2+0.005x-0.029 look like?
*February 10, 2011*

**Math (Truly Need Help)**

H(x)= 0.002x^2+0.005x-0.029 where x is the speed of the car in miles per hour. How can I rewrite the function so that x represe the speed in kilometers per hour. [Find H(x/1.6)]
*February 9, 2011*