Wednesday

October 7, 2015
Total # Posts: 1,033

**Science**

What were five accomplishments of marie curie?
*October 6, 2015*

**Pre Calculas**

7. For the function defined by: f(x)= {x^2, x<=1} {2x+1, x>1} a. evaluate f(0) 8. Solve the following system of equations algebraically. Verify your solution either graphically or by using matrices. 3x-y=0 5x+2y=22 9. Solve the following system of equations algebraically...
*October 6, 2015*

**Pre Calculas**

Thanks Steve for the help
*October 5, 2015*

**Pre Calculas**

Im really struggling and need help with this 1. One of the tables below contains (x,y) values that were generated by a linear function. Determine which table, and then write the equation of the linear function represented by the Table #1 x 2 5 8 11 14 17 20 y 1 3 7 13 21 31 43...
*October 5, 2015*

**american history**

how do you think the Europeans and the tainos perpective on their encounter vary
*October 2, 2015*

**help me with social studies**

"Explain the role of law in limiting U.S. government and protecting citizens" is the exact question.
*October 2, 2015*

**help me with social studies**

There is 6 pages before hand in it giving information, but i've read through it slowly and dozens of times, but i could not find it.
*October 2, 2015*

**help me with social studies**

Text? do you mean my text book? because this unit did not come with a text book.
*October 2, 2015*

**help me with social studies**

What was the role of law limiting in u.s goverment and protecting citizens
*October 2, 2015*

**algebra**

find the solutions to the equation; x^(2/5)-8x(1/5)+16=0
*September 29, 2015*

**Science**

I have homework in which it asks "Describe the difference between elements, mixtures and compounds. (I have done the first sentence as it was fairly easy. Next is the part I don't understand) You need to draw their chemical formulae (for example KCl for potassium ...
*September 26, 2015*

**physics **

If the print area of each tire of a car is 24 inch2 and the tire pressure is 30psi, what the weight of the car in pounds?
*September 18, 2015*

**David A. Brown **

Jonathan measure 2 cups of flour into a bowl on the counter then he spilled part of it and now there is only three eighths cup left how much did he spill
*September 15, 2015*

**Math**

S= L(1-r), solve for r I tried both distributing L and dividing by it, but I am not sure which way is correct. Any help would be much appreciated.
*September 14, 2015*

**Math**

17676
*September 10, 2015*

**Math**

. Jordan’s Jeans Company reported net income for 2014 of $871,800 and the company paid dividends of $0.08 per share in 2014. Given this information (along with the data provided above), compute what Jordan’s Jeans Company reported as retained earnings on its December...
*September 10, 2015*

**math**

In 2014, Timmers, Inc. (a retail clothing company) sold 102,300 units of its product at an average price of $100.00 per unit. The company reported estimated returns and allowances in 2014 of 1.5 percent of gross revenue. Timmers actually purchased 109,500 units of its product ...
*September 10, 2015*

**Physics**

I solved it! It is: ((m_rock*g)-(m_rock/(g*density_rock))*density_liquid*g)/(lower frequency squared) = (m_rock*g)/(higher frequency squared) Then just solve for density_liquid :)
*August 13, 2015*

**math**

If a line whose x- and y- intercepts are equal does not pass through the origin, then its slope must be A. 0 B. 1 C. -1 D. undefined I'm thinking it's 0, I don't know though.
*August 3, 2015*

**math**

The result of adding a number to itself is usually unequal to the result of multiplying the number by itself. For how many different numbers are these results equal? A none B. one C. two D. four
*August 3, 2015*

**math**

If a line whose x- and y- intercepts are equal does not pass through the origin, then its slope must be A. 0 B. 1 C. -1 D. undefined I'm thinking it's 0, I don't know though.
*August 3, 2015*

**math**

That's what I thought, but that's what the question says... Might be a bad question. Thanks though!
*August 3, 2015*

**math**

I watched 1000 ants build an anthill in 5 hours. Working at the same rate, 2500 ants could have built the anthill in ? hours? A. 1 B. 2 C. 3 D. 4 I made a proportion of 1000/5=2500/x, and got 12.5, but thats not a choice. HELPS!
*August 3, 2015*

**math**

In a pseudopythagorean triangle, the sides are all integers and the sum of the square roots of the sides equals the square root of the third side. How many pseudopythagorean triangles are there. A. none B. 1 C. 2 D. more than 2 this is such a confusing question
*July 30, 2015*

**Easy Math??**

Carol started from home on a trip averaging 30 miles per hour how fast must her mother drive to catch up to her in 3 hours if she leaves 30 minutes after Carol? Use an equation to solve your work. a.35 mph b.39 mph c.40 mph I heard that the answer is a, but I don't know ...
*July 30, 2015*

**Easy Math??**

I do believed the question was about 5 years old. Thanks though!!!!
*July 29, 2015*

**Easy Math??**

The stock that Mr. Ames bought cost him $80 a share. The par value of the stock is $100. If the stock pays $6 a year in dividends, what rate of interest is Mr. Ames getting on his money? A.16 2/3% B.7 1/2% C.3% D.6% E.None of the above Personally, what made the problem ...
*July 29, 2015*

**Calculus**

Hi Henry, can you explain the second part of your answer please? Is that the answer to the "What correction needs to be made" part? What is that "i"?
*July 29, 2015*

**math**

If n is a positive integer, n! is the product of the first n positive integers. For example, 4! = 4 x 3 x 2 x 1 =24. If u and v are positive integers and u!=v! x 53, then v could equal A. 6 B. 8 C. 56 D. 57
*July 21, 2015*

**math**

If the lengths of the sides of a rectangle are integers, and if one side is 2 more than another, then the perimeter could equal A. 1998 B. 1999 C. 2000 D. 2002 I started this, but I'm not sure what they're asking and I don't know how to solve it.
*July 21, 2015*

**math**

Of the following, which must be true whenever x^1998 = y^1998? A. x^999=y^999 B. x^1997=y^1997 C. x^1999=y^1999 D. x^2000=y^1000 I tried plugging in 2 for x and y, but the calculator said overflow...
*July 21, 2015*

**Stoichiometry chem**

Just to recap: I divide the grams of the compound by its molar mass. From there, I do the mol conversion from CaCO3 to C and that will by my answer.
*June 27, 2015*

**Stoichiometry chem**

If there is one mole of Carbon for every CaCO3, all I had to do was divide it and that would be my answer (2.498)? What if it was 2 moles of carbon instead of one, what would I have to do then?
*June 27, 2015*

**Stoichiometry chem**

How many moles of carbon are found in 250.0 g of CaCO3? I started off with finding the molar mass of CaCO3, which is 100.09g. From there I divided 250g by 100.09g, but I have no idea what to do from there.
*June 27, 2015*

**Science **

When you change the dna code to mRNA, will A become U or T?
*June 14, 2015*

**math**

A circle of radius 2 is externally tangent to a circle of radius 8. Compute the length of their common tangent.
*June 6, 2015*

**math**

Solve for all real values of x is 9^x+2=240+9^x THIS ONE IS HARD
*June 6, 2015*

**Math**

Joan's stamp collection consists of three books. Two tenths of her stamps are on the first book, several sevenths are in the second, and there are 303 stamps in the third book. How many stamps are there in Joan's collection?
*June 6, 2015*

**math**

In triangle ABC, AC=BC. The point D is on BC such that AB=AD=DC. Compute the measure of angle C. I'm not sure how to do this...
*June 6, 2015*

**Chemistry**

when I do m=M*n I get a really high Number which I don't think is right.
*June 4, 2015*

**Chemistry**

How many grams of zinc metal are required to produce 2.00 L of hydrogen gas at STP according to the chemical equation shown below? Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
*June 4, 2015*

**prealgebra**

find the slope of a road that rises 5 feet vertically for every 45-foot horizontal increase.
*May 14, 2015*

**Algebra 2 Honors**

Hey, we recently started a topic in class that I don't understand well, I just want to post 6 of the problems and ask if they're right or not (some of them I have no idea how to do). 1. If a varies directly as b and b = 18 when a = 27, find a when b = 10. For this I ...
*May 13, 2015*

**Organic chemistry**

What is the product formed when phtalic anhydride reactors with D2O/D+? Thank you in advanced!
*May 13, 2015*

**Chemistry Gas Law**

How many grams of Mg must react with HCl in order to produce 40.0 ml of hydrogen gas at 22 degrees celsius and 1.02 bar? If the magnesium ribbon weighs 1.83mg/mm, how many mm of the ribbon will you require? Thanks in advance for your help!!
*May 12, 2015*

**Math**

The tail on Alex's dog is 5 1/4 inches long this like this between which 2 inch March on a ruler
*May 12, 2015*

**Trig identities**

Thank you so much!
*May 12, 2015*

**Trig identities**

Sin x/[1-cos(-x)] = csc x + cot x Please Verify the Identity. I have been going in circle with this one... Just a hint would be nice. Thank you.
*May 12, 2015*

**chemistry**

Calculate the weight in grams of potassium hydrogen phthalate (KHP, KHC2H3O2, MW 202.2 g/mole) required to neutralize 25.00 ml of 0.1 M NaOH solution.
*April 15, 2015*

**chemistry**

Describe in detail how you would prepare 500 ml of 0.1 M HCl from 6 M HCl stock solution.
*April 15, 2015*

**chemistry**

Describe in detail how you would prepare 1000 ml of 0.1 M NaOH from 6 M of NaOH stock solution.
*April 15, 2015*

**Maths help**

W= rad/s and a = 0.6. My mistake Very sorry reiny it's just that I'm in desperate need of help and no one Is answering my questions. Could you please help me?
*April 12, 2015*

**Maths help **

The angle of a rotating shaft turns in t seconds is given by theta= ω+1/2at^2 and it is given that ω=3 2 rad/s and α=0.6 rad/s to complete θ=4 radians. Determine the time taken to complete θ=4 radians.
*April 12, 2015*

**Maths help**

Two resistors in series, R1 and R2, have a total resistance of 1,600 ohms. The resistance of R2 is 560 ohms less than twice R1. Find the resistance of R1 and R2.
*April 12, 2015*

**Maths help**

The law connecting friction F and load L for an experiment is of the form F =aL+b, where a and b are constants. When F =5.6, L=8.0 and when F =4.4, L=2.0. Find the values of "a" and "b "and the value of F when L=6.5.
*April 12, 2015*

**Maths help**

A manufacture finds the total cost "C" for a product is expressed by C=3x2-8, and the total revenue "R" by R=3x-2, where x is the number of units sold. What is the breakeven point (where total cost=total revenue) to the nearest unit?
*April 12, 2015*

**Maths help **

Two flares are launched from a life raft. The height h of the first flare in metres above the sea is modelled by the formula h1= t2+t+1meters,and the second flare is h2=4-t where t is the time 12 in seconds after the flare is launched. Determine (i) Time taken and (ii) Height ...
*April 12, 2015*

**Physics**

1. A point on the edge of a large wheel of radius 0.45 meters moves through an angle of 170o at a constant angular velocity of 0.25 radians/sec. . (a) Find the length (in meters) of the arc described by the point. (b) Find the linear velocity (in m/sec) of a point located on ...
*April 6, 2015*

**Biology**

8) Describe the difference between a prosthetic group, cofactor, and coenzyme; provide an example of each.
*March 24, 2015*

**Biology**

What does b-mercaptoethanol do to secretory proteins?If you forgot to add b-mercaptoethanol to a secretory protein, would the protein's migration likely speed up or slow down? Why?
*March 22, 2015*

**Biology**

For each of the following characteristics, will the migration of the protein speed up, slow down, or remain unchanged if you do not add SDS? a)increase molecular weight of protein b) increase concentration of acrylamide c)decrease charge on protein d) increase surface area of ...
*March 22, 2015*

**Biology**

What does b-mercaptoethanol do to secretory proteins?If you forgot to add b-mercaptoethanol to a secretory protein, would the protein's migration likely speed up or slow down? Why?
*March 22, 2015*

**Biology**

What does b-mercaptoethanol do to secretory proteins?also...If you forgot to add b-mercaptoethanol to a secretory protein, would the protein's migration likely speed up or slow down? Why?
*March 22, 2015*

**Biology**

3) For each of the following characteristics, will the migration of the protein speed up, slow down, or remain unchanged if you do not add SDS? a)increase molecular weight of protein b) increase concentration of acrylamide c)decrease charge on protein d) increase surface area ...
*March 22, 2015*

**Biology**

What does b-mercaptoethanol do to secretory proteins?also...If you forgot to add b-mercaptoethanol to a secretory protein, would the protein's migration likely speed up or slow down? Why?
*March 22, 2015*

**Biology**

3) For each of the following characteristics, will the migration of the protein speed up, slow down, or remain unchanged if you do not add SDS? a)increase molecular weight of protein b) increase concentration of acrylamide c)decrease charge on protein d) increase surface area ...
*March 22, 2015*

**Biology**

also...If you forgot to add b-mercaptoethanol to a secretory protein, would the protein's migration likely speed up or slow down? Why?
*March 20, 2015*

**Biology**

What does b-mercaptoethanol do to secretory proteins?
*March 20, 2015*

**Biology**

3) For each of the following characteristics, will the migration of the protein speed up, slow down, or remain unchanged if you do not add SDS? a)increase molecular weight of protein b) increase concentration of acrylamide c)decrease charge on protein d) increase surface area ...
*March 20, 2015*

**Algebra 2**

Find a third-degree polynomial equation with rational coefficients that has roots -1 and i+1
*March 13, 2015*

**Physics**

The coefficient of static friction between the m = 3.75-kg crate and the 35.0° incline of the figure below is 0.320. What minimum force vector F must be applied to the crate perpendicular to the incline to prevent the crate from sliding down the incline?
*March 10, 2015*

**Statistics**

A history class is comprised of 5 female and 8 male students. If the instructor of the class randomly chooses 8 students from the class for an oral exam, what is the probability that 2 female students and 6 male students will be selected? Round your answer to decimal places.
*March 10, 2015*

**Chemistry**

The mass of spectrum of 2,4-dimethylpentane shows peaks at m/z 43, 57, and 85. Show the fragments which produce these peaks.
*March 5, 2015*

**Chemistry**

Consider the following reaction: CO(g)+H2O(g)⇌CO2(g)+H2(g) Kp=0.0611 at 2000 K A reaction mixture initially contains a CO partial pressure of 1348torr and a H2O partial pressure of 1780torr at 2000 K. Calculate the equilibrium partial pressure of CO2. Calculate the ...
*February 25, 2015*

**Biology**

describe how a population is thought to evolve through natural selection. Provide an example (specifically, the peppered moth)
*February 20, 2015*

**Chemistry**

name all the possible isomers of methyl nitrobenzoate and nitroacetanilide which can be formed
*February 11, 2015*

**Organic Chem**

Why does the carotene elute from the column before the chlorophylls?
*February 11, 2015*

**Organic Chem**

Why does the carotene elute from the column before the chlorophylls?
*February 11, 2015*

**Organic Chemistry**

Why does the carotene elute from the column before the chlorophylls?
*February 11, 2015*

**Chemistry**

Why does the carotene elute from the column before the chlorophylls?
*February 11, 2015*

**Chemistry**

Why does the carotene elute from the column before the chlorophylls?
*February 11, 2015*

**Chemistry**

Why does the carotene elute from the column before the chlorophylls?
*February 11, 2015*

**Chemistry**

A solution of 4-methyl-3-penten-2-one in ethanol shows an absorbance of 0.52 at 236 nm in a cell with a 1-cm light path. Its molar absorptivity in ethanol at that wavelength is 12,600 M^-1 cm^-1. What is the concentration of the compound?
*February 11, 2015*

**Chemistry**

A solution of 4-methyl-3-penten-2-one in ethanol shows an absorbance of 0.52 at 236 nm in a cell with a 1-cm light path. Its molar absorptivity in ethanol at that wavelength is 12,600 M^-1 cm^-1. What is the concentration of the compound?
*February 11, 2015*

**Chemistry**

Why does the carotene elute from the column before the chlorophylls?
*February 11, 2015*

**Chemistry**

Why should a mixture to be separated by column chromatography be introduced onto the column in a minimum amount of solvent?
*February 11, 2015*

**Chemistry**

Arrange the following compounds in order of decreasing ease of elution from a column of silica gel: a) 2-octanol; b) 1,3-dichlorobenzene; c) tert-butylcyclohexane; d) benzoic acid
*February 5, 2015*

**Chemistry**

name* Thanks for help DR. Bob
*February 4, 2015*

**Chemistry**

Okay i'll keep my answers the same. What do you think is the answer. Tert-butylcyclohexane > 1,3-dichlorobenzene > 2-octanol > benzoic acid
*February 4, 2015*

**Chemistry**

What precautions must be taken when you introduce a mixture of compounds to be separated onto a liquid chromatography adsorbent column?
*February 4, 2015*

**Chemistry**

oh no man. i just want different answers to see if the answers are right. And if people agree. I just don't want to take chances. Do you have a background in chemistry or something? I have no background in chemistry so i don't know if i'm seeing a right answer or ...
*February 4, 2015*

**Chemistry **

Once the adsorbent is packed in a liquid chromatography column, it is important that the level of the elution solvent not drop below the top of the adsorbent. Why?
*February 4, 2015*

**Chemistry **

What precautions must be taken when you introduce a mixture of compounds to be separated onto a liquid chromatography adsorbent column?
*February 4, 2015*

**Chemistry **

Once the adsorbent is packed in a liquid chromatography column, it is important that the level of the elution solvent not drop below the top of the adsorbent. Why?
*February 4, 2015*

**physics**

a metal object is suspended from a spring balance scale. the scale reads 800 N when it is suspended in air and 700 N when the object is completely submerged in water. find the buoyant force, the volume and the density of the metal.
*February 3, 2015*

**world history**

why is the ability to debate still important todat
*February 2, 2015*

**chemistry**

In 100 mL of distilled water,1.0g of thallium cholirde is added. How much of the 1.0g of TlCl doen't dissolve? The Ksp of TlCl is 3.6 x 10-6
*February 2, 2015*

**chemistry**

Please help !? Knowing that the concentration of Ag+ in a silver chromate solution is 1.5 x 10-3 M, calculate its solubility product at 25°C.
*February 2, 2015*

**chemistry**

Stuck on this one please help ! The solubility of barium sulphate, BaSO4, is 2.4 x 10-4 g/100 mL of solution. Calculate the Ksp of this solution.
*February 2, 2015*

**chemistry**

In 100 mL of distilled water,1.0g of thallium cholirde is added. How much of the 1.0g of TlCl doen't dissolve. The Ksp of TlCl is 3.6 x 10-6.
*February 1, 2015*