Monday

July 6, 2015

July 6, 2015

Total # Posts: 406

**Chemistry**

Calculate the sodium ion concentration when 50.0 mL of 2.0 M sodium carbonate is added to 100.0 mL of 3.0 M sodium bicarbonate.
*May 27, 2015*

**Math**

You are considering two mutual funds for your investment. The possible returns for the funds are dependent on the state of the economy and are given in the accompanying table. State of the Economy | Fund A | Fund B Good | 20% | 40% Fair | 10% | 20% Poor | -10% | -40% You ...
*May 24, 2015*

**chemistry**

Determine the hydroxide ion concentration in a solution that is 0.0004 M HCl. Answer in units of M. I have no idea how to start, I just need to know what I need to solve for and hoe to set it up, I know the formula pOH^-=-log[OH^-] I just don't know where to plug things in...
*April 16, 2015*

**math**

Please show your work. Tutors will not do your homework for you. Please show your work for any question that you are posting.
*March 29, 2015*

**math**

In the triangles, we have XY = 2AX = 2YB and AZ/ZC = 2/3. Find the ratio of the area of triangle YBC to the area of triangle ZYC.
*March 29, 2015*

**math**

The function f(x) = cx/2x+3 satisfies f(f(x))=x for all real numbers x\= -3/2. Find c.
*March 26, 2015*

**math **

A rectangle has an area of 400 cm^2. If the rectangle is a square, what is its perimeter?
*March 26, 2015*

**Math**

Suppose you have a cache of radium, which has a half-life of approximately 1590 years. How long would you have to wait for 1/5 of it to disappear?
*March 26, 2015*

**math**

But what about how far he is from the lightning?
*February 27, 2015*

**math**

During a severe thunderstorm, Tim saw a flash of lightning and then six seconds later heard a clap of thunder. The speed of sound is 1088 ft/sec. How far is Tim from the lightning? Nearest Thousand Feet.
*February 27, 2015*

**Algebra**

Use algebra tiles to determine if 2(x +3) is equivalent to 2x +3. Explain your answer thanks
*January 21, 2015*

**Algebra please help**

Lisa evaluated the expressions 2x and x squared for x=2 and found that both expressions were equal to 4. Lisa concluded that 2x and x squared are equivalent expressions. How could you show. Lisa that she is incorrect? Please help explain thanks
*January 21, 2015*

**Pre calc**

A boat is going 30 mph. It's direction is 100 degrees east of north. The water current is 15 mph and has a direction of 22 degrees east of north. Find the magnitude, and direction of boat.( with water current)
*January 20, 2015*

**Pre calc**

A boat is going 30 mph with a direction of 100 degrees east of north. The water current is 15 mph with a direction of 22 mph. What is the magnitude of boat and direction
*January 20, 2015*

**Algebra 1**

The town of Rayburn received 6 more inches of snow than the town of Greenville. Let g represent the amount of snow in Greenville. Write an algebraic expression to represent the amount of snow in Rayburn.
*January 14, 2015*

**Algebra 1 **

Jill, Meg and Beth are sisters. Jill is 2 years younger than Meg. Beth is half as old as Meg. Let m represent Meg'a age. Write 2 other algebraic expressions based on the situation. Tell what each expression represents, and what the variable stands for in each expression. ...
*January 14, 2015*

**algebra 1**

A very old vending machine accepts only nickels (n) and dimes (d). Candy costs up to $0.50, but sometimes the machine will dispense candy without any coins being inserted into the machine. Which inequality shows all of the ways to obtain a candy bar from the machine?
*January 13, 2015*

**Algebra**

Find a if the point (3,a) is on the line that passes through (-2,7) and (5,-3).
*December 31, 2014*

**P.E. help please**

45% of 10 is 4.5 So the answer is c Multiply your answer by 10 and the number your trying to get the % from by 10 as well 10x10=100 4.5x10=45 Percent is a calculation of part of 100. And in this case you make the "10" a 100 by multiplying it by 10
*December 3, 2014*

**statistics**

Well if of 100 students there is 70 boys, and only 70% of the boys are in sports, all you need to do is find 70% of 70. Which is 49. 70 x 0.07= 4.9 4.9x10=49
*December 3, 2014*

**Chemistry**

If a solution contains 0.65mol of OH−, how many moles of H+ would be required to reach the equivalence point in a titration?
*November 16, 2014*

**math**

a man 5 ft tall casts a shadow of 6 ft. The angle of elevation f the sun is?
*November 15, 2014*

**Physics**

A puck of mass 0.165 kg, initially resting on ice, is hit by a stick to gain a speed of 32.0 m/s and then slides 25.0 m to lose 5.00% of its kinetic energy. (a) What is the work done on the puck by the stick? (b) What is the kinetic friction coefficient between the ice and puck?
*October 11, 2014*

**Business math**

Order for 620 dresses from China, cost is $40 a gown, markup based on selling is 76%, what is the selling price of each gown?
*September 26, 2014*

**Chemistry**

1 ersk * ( 100 ed / 12 ersk ) * ( 10 ebb / 9.5 ed ) * ( 1 zum / 5 ebbs) Calculate it yourself
*September 22, 2014*

**algebra**

If only natural gas is hit, the income will be $140,000. If nothing is hit, there will be no income. If the probability of hitting oil is 1/40 and if the probability of hitting gas is 1/20, what is the expectation for the drilling company?
*September 10, 2014*

**physics**

A rifle with a muzzle velocity of 480 m/s shoots a bullet at a target 45.6 m away. How high above the target must the rifle barrel be pointed to ensure that the bullet will hit the target? Neglect air resistance.
*September 7, 2014*

**chemistry**

Nevermind, I did it, I should be paying you for all this help ;) I had to take other pk 2.35+log10(102) =4.35
*August 26, 2014*

**chemistry**

9.78+log10(1/102) =7.77 sounds good?
*August 26, 2014*

**chemistry**

thank you I'm looking into this albeit totally lost atm
*August 26, 2014*

**chemistry**

glycine and lysine, have the following values of the relevant acid dissociation constants (pKa) glycine, pKa=2.35 lysine,pKa=10.79 For an aqueous solution of glycine alone, calculate the value of pH at which the ratio of the concentration of neutral glycine zwitterions to the ...
*August 26, 2014*

**Chemistry Help!!!!!!!!!!!!!!**

a) Carbon [He]2s²p² b) Silicon [Ne]3s²p² Hund rule -> fill from bottom to top Pauli -> first you fill orbitals with one spin and then the other ex. if you have 4 electrons in p orbitals P 11 1 1 __ __ __ p.s. if they don't delete this too
*August 26, 2014*

**chemistry**

got it! ka= 3.26*10^-3 so pKa=2.49 tnx
*August 26, 2014*

**chemistry**

A 1.11 M solution of fluoroacetic acid, FCH2CO2H, is 5% dissociated in water. Calculate the value of the pKa of FCH2CO2H. pKa: ?? I dn't even know how to strt with this
*August 26, 2014*

**chemistry**

what image? degree of polymerization is like this propylene is H2C=CH-CH3 so 3C and 6C molec. weigth (12*3)+6 = 42 g/mol n = 3.091*10^5 / 42 = 7359.52
*August 25, 2014*

**chemistry**

it's ok, that's 372 nm it's uv I got same result
*August 24, 2014*

**chemistry**

volts and eV aren't like "multiples" eV is an energy, V a potential taht's V and it's checked correct ;)
*August 24, 2014*

**chemistry**

Determine the potential (V) by which a proton must be accelerated so as to assume a particle wavelength of 0.0293 nm. ---- This is what I did, dunno if right - wavelength in meters = 2.93*10^-11 m - used DeBroglie relation to find energy lambda = h / mv, v from kinetic energy...
*August 24, 2014*

**chemistry**

Calculate the wavelength (in m) of a photon capable of exciting an electron in Li2+ from the state n= 3 to the state n=5
*August 24, 2014*

**chemistry**

Thank you!
*August 24, 2014*

**chemistry**

a) Calculate the number of moles of nitrogen dioxide, NO2, that could be prepared from 79.0 mol of nitrogen oxide and 82.0 mol of oxygen. 2NO(g)+O2(g)⟶ 2NO2(g) b) Identify the limiting reagent and the excess reagent in the reaction. What would happen to the potential ...
*August 24, 2014*

**chemistry**

Reaction is second order, even if your plot of 1/T doesn't give a perfectly straigth line. a) 2 b) 0.71 my reagrds to will
*July 26, 2014*

**Chemistry**

A compound of chlorine and fluorine, ClFn, reacts at about 75oC with uranium metal to produce uranium hexafluoride, UF6 and chlorine monofluoride, ClF (g). A quantity of uranium produced 3.53g UF6 and 343 mL ClF at 75oC and 2.50 atm. What is the formula (n) of the compound?
*May 26, 2014*

**Math**

Nina walked 15 yards to Paul's house. They then went hiking. Which rule shows how many yards Nina walks for every yard Paul walks? a. p=n+15 b. n=p+15 c. P=15-n d. n=p-15
*March 20, 2014*

**physics**

An X-ray tube used for cancer therapy operates at 4.04 MV with a beam current of 23.4 mA striking a metal target. Calculate the power of this beam.
*February 12, 2014*

**algebra**

x^3+4a+5a^2x^6 ascending order
*February 9, 2014*

**Algebra**

7. Paula is an office manager for ABC Advertising. She has been tasked with finding a copy machine that falls within a budget of $750 per month. She finds a company that will lease the machine for $275 a month. Each copy costs 4¢ and a ream of 500 sheets of paper costs $5...
*February 2, 2014*

**Algebra**

1. A firm pays $1.75 for each copy of a magazine and sells each one for $2.50. There is a fixed monthly cost of $40 for printing the publication. If the firm wants to make $550 dollars next month, how many magazines do they have to sell?
*February 2, 2014*

**Introductory to algebra**

simplify both sides of the following equations as much as possible and the solve: 4x+2-3x=4+1
*January 20, 2014*

**Biology**

Could someone please explain Endocytosis(phagocytosis, pinocytosis and receptor-mediated endocytosis) in simplest way? I do not understand
*October 23, 2013*

**calculus**

Find the area bounded by {y=x2−4 y=4−x2 • sketch the region described • determine any intersection point(s) for the curves (show work!!) • write out the integral(s) that will calculate the area • determine the area (may use a calculator)
*October 3, 2013*

**chemistry Pleae**

thankyou its meant to be propyl butanoate and sodium hydroxide
*August 22, 2013*

**chemistry Pleae**

C7H14O2 + NaOH What will this combination make? and can it be balanced?
*August 22, 2013*

**chemistry**

Dr bob they will go on different carbons, sue knows this they are called isomers, do you have a list of the isomers for this compound?
*August 21, 2013*

**Statistics**

A researcher surveyed college students to study their opinion about the proposed change in smoking rules. The researcher asked a group of 30 students: 12 of them supported the change, 13 of them did not, and 5 had no opinion. This is not a binomial model because... A. ...the ...
*July 29, 2013*

**math**

Maryann rolls a 6-sided dice six times. How many ways can she roll the dice so that the sum of her numbers is 10?
*July 16, 2013*

**physics**

A car is being pulled out of the mud by two forces that are applied by the two ropes shown in the drawing. The dashed line in the drawing bisects the 30.0° angle. The magnitude of the force applied by each rope is 2900 newtons (N). (a) How much force would a single rope ...
*June 28, 2013*

**physics**

A woman stands on a scale in a moving elevator. Her mass is 68.0 kg, and the combined mass of the elevator and scale is an additional 713 kg. Starting from rest, the elevator accelerates upward. During the acceleration, the hoisting cable applies a force of 9000 N. What does ...
*June 25, 2013*

**Math or business**

What will $30,000 earn after 6 yrs at 2.25%?
*May 29, 2013*

**calculus**

for the next 7 years how much should I set aside sp that in years 7-12 i can make $4,000.00/month payments?
*May 4, 2013*

**Math (Algebra)**

187. each got 3 ice creams and each (except 4 of them) recieved 1 cookie
*May 3, 2013*

**Math**

9:15 am. Answer could vary depending on location of Testing. For example if the class were in an airplane it is possible to start the test in one time zone and finish in another.
*May 2, 2013*

**Alegbra 1**

X^2-12=-11 First add 11: x^2-12+11=0 Next: (x-11)(x-1)=0 Set each equal to 0: (x-11)=0 (x-1)=0 Get x alone by adding: x=11 x=1 Answer: (11,1) Check work by plugging numbers into original equation.
*May 2, 2013*

**math**

30 kg -12kg=18 kg 18kg*5loads=90kgs of sand 1kg= 1000grams 90,000grams of sand
*May 2, 2013*

**math**

Small 1/2= .50 Medium 2/5= .40 That means large is .10 10% of the shirts = 5 shirts 5 is 10% of 50. There are a total of 50 shirts.
*May 1, 2013*

**Algebra**

4.534 secs. not 100% sure
*May 1, 2013*

**Biology**

Question 3 I Think the answer is actually d- slow and fast twitch. Reference Hoefnagels "Biology concepts and investigations" page 595 28.6 B. Muscles contain slow and fast twitch fibers.
*April 30, 2013*

**jardan high. general science**

water,anchorge,photosynthesis,mineral,food,support. The main functions of roots are { } and taking in { } and { }. The stems { } the other parts of the plant and transport { },{ } and around the plant.the leaves are the main part making { } by { }.
*April 8, 2013*

**Physics**

A physics teacher (mass = 84.5 kg) is jogging through the woods and runs straight into a large oak tree at 3.5 m/s. Rebound speed is measured at 2.3 m/s in the opposite direction. If the time of contact with the tree is 45 milliseconds, what is the magnitude of the force that ...
*March 18, 2013*

**Geometric Sequence**

The product of the first five terms of a geometric progression is 32. If the fourth term is 17, compute the second term.
*March 12, 2013*

**math**

The product of the first five terms of a geometric progression is 32. If the fourth term is 17, compute the second term.
*March 12, 2013*

**Maths B**

Andrew got 68 for both English and Maths. The mean for english was 52 and the mean for Maths was 55. The standard deviations were 10 and 8 respectively. Determine the subject in which andrew did better
*March 9, 2013*

**Math**

what is arccot 3.107 equals to in rad?
*February 28, 2013*

**Algebra II**

A line has a slope of 2 and contains the points (1, 3) and (2, y). The value of y is what? Please explain in detail
*February 22, 2013*

**Geometry**

Picture given with problem: media.glynlyon(dot)com/g_geo_2012/12/img_geou12abc_8.gif If AC = 20, AE = 25, and AB = 5, what is the length of AD? Please explain how this is found, I've got a few problems like this and have no idea how to do it.
*January 14, 2013*

**Consumer Math**

Thank you, I was just having some trouble deciding how to do it.
*January 11, 2013*

**Consumer Math**

Compute the square footage of carpet needed to cover a room 12' 3" x 18' 4".
*January 11, 2013*

**chemistry **

Copper can be determined gravimetrically by precipitation as copper(I)thiocyanate, CuSCN. A wrought aluminum-copper sample(4.5167 g) was dissolved in a minimum amount of concentrated HCl followd by the additon of 25 ml of sulfurous acid to reduced the copper. This solution was...
*December 22, 2012*

**Chemistry**

The determination of 4.000 mmol of ZnCl2 is performed gravimetrically by the addition of NaCN solution in a Total volume of 200.00ml. Ksp = 3.0X10^-16 for Zn(CN)2. State and verify all assumption. Assume cyanide does not hydrolyze. a. Derive the COC and COM equations for the ...
*December 22, 2012*

**PLEASE HELP-CHEMISTRY**

A cyclopropane-oxygen mixture is used as an anesthetic. If the partial pressure of cyclopropane in the mixture is 334 mmHg and the partial pressure of the oxygen is 1.02 atm, what is the total pressure of the mixture in torr? ?
*December 19, 2012*

**CHEMISTRY HELP NOW**

A balloon at a pressure of 755 torr and a volume of 5.00 L was allowed to rise in the atmosphere to a point at which the pressure inside and outside the balloon was 697 torr. What was the volume of the balloon at that altitude, assuming the temperature was constant?
*December 19, 2012*

**Math**

Jean surveyed 25% of all eighth graders and 75% of all 7th graders. John surveyed 50% of all eighth graders and 50% of all 7th graders at the same school. Jean surveyed a total of 152 John surveyed a total of 144 What is the number of eighth graders?
*December 17, 2012*

**Math **

what is the equation for the perpendicular bisector of the line segment whose endpoints are (-7,2) (-1,-6)
*November 29, 2012*

**Math **

what is the equation for the perpendicular bisector of the line segment whose endpoints are (-7,2) (-1,-6)
*November 29, 2012*

**Math **

what is the equation for the perpendicular bisector of the line segment whose endpoints are (-7,2) (-1,-6)
*November 29, 2012*

**Business Math Question**

You borrow $2,600 and repay the loan in 12 monthly installments of $232. What was the finance charge per $100 of the amount financed?
*November 8, 2012*

**Business Math Question**

Finance charge of $2.50 per $100 for 3 payments.
*November 8, 2012*

**Business Math Question**

Find the finance charge per $100 on a loan of $12,600 with a finance charge of $1,638.
*November 8, 2012*

**College Chemistry**

Using the molar volume (STP) or the ideal gas law equation, determine the molar mass,g/mole, of each of the following. A: 11.2g of a gas that has a volume of 1.50Lat STP? B: .0710g of a gas that has a volume 825ml at 1 atm
*October 21, 2012*

**College Chemistry**

A 14.0 g sample of Krypton has a temperature of 25C at 625mm Hg. What is the volume, in Milliliters, of the krypton?
*October 21, 2012*

**economics**

which of the following statements about inflation are true? check all that applies a) policy makers also worry about a negative inflation rate, or deflation b) painful government actions may sometimes be necessary to bring down a high inflation rate. c) A moderately high ...
*September 23, 2012*

**Calculus**

Nevermind, I got it! I forgot that I could divide everything by the highest power x in the denominator.
*September 14, 2012*

**Calculus**

I'm supposed to find the limit as x approaches infinity of (2-x-sinx)/(x+cosx). I've thought about using the squeeze theorem, but I'm not sure it applies here. Can someone point me in the right direction? Thanks.
*September 14, 2012*

**Math**

No Idea, the question completely asks that. I was thinking about 12% annually compounded, but the answer I got was wrong due to Solve and Check.
*September 8, 2012*

**Math**

How much must you deposit in an account that pays 6% semi-annual interest, compounded annually, to have a balance of $9000 in 15 years? I'm stuck with this question, please explain the steps for the answer.
*September 8, 2012*

**Math**

How much must you deposit in an account that pays 6% semi-annual interest, compounded annually, to have a balance of $9000 in 15 years?
*September 8, 2012*

**statistics**

Can a percentile have the VALUE of 517? Can a percnetile have the VALUE -5.8? Can a percentile have the RANK 517? Can a percnetile have the RANK -5.8?
*August 29, 2012*

**statistics**

is it likely to arrive at a correct research conclusion after making an incorrect statistical conclusion?
*August 29, 2012*

**reading**

EVERYBODYS ANSWER IS DIFFERENT!!! -.-
*August 9, 2012*