Sunday

February 1, 2015

February 1, 2015

Total # Posts: 4,208

**physics**

is the work needed to bring a car's speed from 0 to 10 km/h less than, equal to ,or more than the work needed to bring its speed from 10 to 20 km/h? if the amounts of work are different ,what is the ratio between them?
*February 28, 2013*

**Analytical Chemistry**

its alright. I figured out the answer. thanks for your help! :)
*February 27, 2013*

**Analytical Chemistry**

I did not get the right answer by this method.
*February 27, 2013*

**Analytical Chemistry**

I apologize that the ice chart got smushed like this when i posted the problem.
*February 27, 2013*

**Analytical Chemistry**

Calculate the pH at the equivalence point for the titration of 0.160 M methylamine (CH3NH2) with 0.160 M HCl. The Kb of methylamine is 5.0× 10–4. Methylamine is a weak base and reacts with HCl to give the methylammonium ion. HCl + CH3NH2 <---> CH3NH3^+ + Cl^- ...
*February 27, 2013*

**math**

why does lxw=a work
*February 26, 2013*

**Math**

a group of 100 students took a quiz. Their average score was 76 points. If the average score for boys was 80 points and the average score for girls was 70 points, how many girls participated in the quiz
*February 26, 2013*

**Analytical Chemistry**

Show the predominant form of the amino acid tyrosine at pH=13.9 and ph=7.8. Be sure to include the proper number of hydrogens on heteroatoms and the correct formal charges on atoms. I calculated the pka values for COOH (pka=2.41) NH3 (pka=8.67), and OH (pka=11.01) but i'm...
*February 26, 2013*

**Analytical Chemistry**

You prepare a solution from 10.0 mL of 0.100 M MOPS buffer (3-morpholinopropane-1-sulfonic acid) and 10.0 mL of 0.086 M NaOH. Next, you add 1.00 mL of 8.87 × 10-4 M lidocaine to this mixture Denoting lidocaine as L, calculate the fraction of lidocaine present in the form...
*February 26, 2013*

**Analytical Chemistry**

I got the answer, thanks!
*February 26, 2013*

**Analytical Chemistry**

What fraction of piperazine (perhydro-1,4-diazine) is in each of its three forms (H2A, HA–, A2–) at pH 7.05? Not sure how to find k1 and k2 needed for the fraction formulas...please help :(
*February 26, 2013*

**Literature**

Repeated words, papragrapgh transition, conjunction sentences etc. Just want to make sure on my writing. I am in seventh grade. I don't want to copy and paste it on here in case other kids might use my writing. Other wise I would ask you to look at it. I wish.
*February 26, 2013*

**Literature**

Hi where can I find a free on line thing to check my writing ?
*February 26, 2013*

**physics**

Two spherical shells have a common center. A -2.00 × 10-6 C charge is spread uniformly over the inner shell, which has a radius of 0.050 m. A +5.50 × 10-6 C charge is spread uniformly over the outer shell, which has a radius of 0.15 m.
*February 25, 2013*

**Math**

Find the equation of the secant line to the graph of y= 2x^3-3x^2+4x-1 from x=1 to x=3. Give your answer in slope-intercept form.
*February 23, 2013*

**Analytical Chemistry**

Phosphoric acid is a triprotic acid with the following pKa values: pka1: 2.148 pka2: 7.198 pka3: 12.375 You wish to prepare 1.000 L of a 0.0100 M phosphate buffer at pH 7.45. To do this, you choose to use mix the two salt forms involved in the second ionization, NaH2PO4 and ...
*February 22, 2013*

**Analytical Chemistry**

Yes I have online homework which I use to submit my homework on. I calculated H2CO3 and got the same value as yours. then I solved for x and got 2.3 x 10^-6 M. Finally i plugged it into the ph formula to get a ph of 5.64. Thank you so much! It was correct!
*February 22, 2013*

**Analytical Chemistry**

Carbon dioxide dissolves in water to form carbonic acid, which is primarily dissolved CO2. Dissolved CO2 satisfies the equilibrium equation. CO2(g) <----> CO2(aq) The acid dissociation constants listed in most standard reference texts for carbonic acid actually apply to ...
*February 22, 2013*

**History**

I need help on how people influenced us. I am doing some history homework about the great depression (late 1920's through early 1940's) and I need some future connections like how did Duke Ellington influence us today? Or Walt Disney influence us today...ect. I can'...
*February 20, 2013*

**life orientation**

What according to the basic conditions of employment act applies wwith regard to contraventions
*February 20, 2013*

**biology helppppppppppppppp**

(This homework question has been removed due to a copyright claim submitted by The Open University.)
*February 20, 2013*

**English**

well i am trying thanks anyway!
*February 16, 2013*

**English**

incentive,incorporate
*February 16, 2013*

**English**

AS Leo explained a failed business deal that had once_____e(d) him,he______(e)d into the even more interesting tale of his romance with Molly, his business partner. My answers:rigor, curtail Is this correct?
*February 16, 2013*

**english**

which word would be the best word to use in this sentence... My aunt has only______success in quitting smoking.Every few monthsshe ____sto temptation,and then she has toquit all over again. succomb and curtail..Is this correct?
*February 16, 2013*

**English**

Thanks for your help!
*February 16, 2013*

**English**

1.squander 2.digress 3.rigor 4.incentive 5.devastate 6.succumb 7.indispensable 8.incorporate 9.curtail 10.intermittent
*February 16, 2013*

**biology help?**

In 1857, Louis Pasteur discovered that yeast is a living organism. The activity of yeast causes fermentation – baker’s yeast, Saccharomyces cerevisiae, has been used for centuries in the production of bread, beer and wine. In the absence of oxygen, yeast is able to ...
*February 15, 2013*

**Math on graphs**

If 30 3rd graders owned birds, how many third graders were surveyed? Reptiles 5% Birds 5% Fish 10% Cats 35% Dogs 45% I did 5% of 30 = .05 x 30 = 1.5 30/1.5 = 20 third graders BUT I am thinking I am doing something wrong? Where did I go wrong? Should it be 30/.05 = 600 students...
*February 14, 2013*

**Math help ??**

Oops I meant 30 third graders.
*February 14, 2013*

**Math help**

If 20 3rd graders owned birds, how many third graders were surveyed? Reptiles 5% Birds 5% Fish 10% Cats 35% Dogs 45% I did 5% of 30 = .05 x 30 = 1.5 30/1.5 = 20 third graders BUT I am thinking I am doing something wrong? Where did I go wrong? Should it be 30/.05 = 600 ...
*February 14, 2013*

**Math**

how to solve polynomiels?
*February 11, 2013*

**Pre Algebra**

I have to design new dice for a board game. I have to use two standard cubes each with six faces and number then in such a way the the probability of rolling the numbers 1-12 are the same
*February 11, 2013*

**Math**

Write a number sentence. Marshall sleeps 8 hours each day. How many hours does Marshall sleep in one week? How many hours is Marshall awake each day
*February 11, 2013*

**physics**

A crane is used to hoist a 500kg crate vertically at a constant velocity of 4 meters per second. Ignore the effects of friction. a) calculate the magnitude of the net force experienced by the crate b) calculate the magnitude of the force applied by the cable on the crate
*February 11, 2013*

**math**

how many square feet are there in an area of 1.00 square meters(1ft=0.305m)?
*February 10, 2013*

**geometry**

Got it! A) Write a variable expression for the area of the picture. x² <==ANSWER B) Write a variable expression for the total area of the poster. (x + 15)(x + 6) <==ANSWER C) Use your solutions to parts A & B to write a variable expression for the area of the border...
*February 8, 2013*

**geometry**

a poster art exhibition is to display a square picture with a white border around it. The border must be 10 in. wide at the bottom, 5 in. wide at the top, and 3 in. wide on each side. Using x to represent the length of a side of the picture. A) Write a variable expression for ...
*February 8, 2013*

**Solving linear equations**

You need to look at the differences between each number. At some point a pattern will repeat, and you follow the differences to determine the next number in a sequence. Do you have an example you can post? Example: 2,5,6,8,11,12 The difference between 2 & 5 is 3 The difference...
*February 8, 2013*

**math**

how many square feet are there in an area of 1.00 square meters(1 ft=0.305)
*February 8, 2013*

**Chemistry**

At a certain temperature, the solubility of gas in water at 2.04 is 48.0 . Calculate the solubility of gas in water, at the same temperature, if the partial pressure of gas over the solution is increased from 2.04 to 6.00 .
*February 8, 2013*

**physics**

From a height of 2.15 m above the floor of Boston's Fleet Center, forward Paul Pierce tosses a shot straight up next to the basketball hoop with a KE of 5.40 J. If his regulation-size. basketball has a mass of 0.600 kg, will his shot go as high as the 3.04 m hoop? Use the ...
*February 7, 2013*

**world history **

The development of an atomic bomb by the United States did which of these? A. pressured German leaders to surrender B.increased tensions between Truman and Stalin C. worried the leaders of France and Great ritain D.led Stalin to postpone a Soviet invasion of Japan
*February 7, 2013*

**U.S History **

The development of an atomic bomb by the United States did which of these? A. pressured German leaders to surrender B.increased tensions between Truman and Stalin C. worried the leaders of France and Great ritain D.led Stalin to postpone a Soviet invasion of Japan
*February 7, 2013*

**Math**

How to divide4/5 divide 7/8
*February 5, 2013*

**Algebra 1 I need help!!!!!!!!!!!!!!!!**

8.A number raised to a negative exponent is negative. Is it always , never, or sometimes. 7. Evaluate 1/2a^-4b^2 a = -2 and b = 4 remember a^to the negative 4 6. Simplify. Write in scientific notation. (9 x 10^-3)^2 Thanks to anyone who helps right away and need right answer ...
*February 4, 2013*

**Physics**

A particle is traveling in a straight line at a constant speed of 28.5 m/s. Suddenly, a constant force of 12.0 N acts on it, bringing it to a stop in a distance of 61.9 m. (a)Determine the time it takes for the particle to come to a stop. s (b) What is its mass? kg
*February 4, 2013*

**math**

The graph of a function is horizontally compressed by a factor of 5 and vertically compressed by a factor of 2 Find an equation for this compressed function in terms of the function f(x)
*February 4, 2013*

**Calculator Question**

how do I input ln7/ln2/5600 correctly in my calculator to get 2900 as my answer?
*February 4, 2013*

**Chemistry**

What is the activity coefficient of H^+ in a solution containing 0.073 M HCl and 0.0090 M Ca(ClO4)2? What is the pH of the solution? I believe I have to find the ionic strength of the solution first, but I don't know how to find it when 2 solutions are involved.
*February 4, 2013*

**Chemistry**

Thank you! That was the correct answer. Plus I finally figured out why that was the correct answer :)
*February 4, 2013*

**Chemistry**

Complete the charge balance equation for an aqueous solution of H2CO3 that ionizes to HCO3^- and CO3^2- ______ = ______ + _______ + _______ Given choices: [HCO3^-],[CO3^2-], [OH^-], 2[H^+], [H2CO3], 2[CO3^2-], 3[H^+], {H^+] I don't understand how to do charge balance :(
*February 4, 2013*

**Chemistry**

Thank you for answering! I got .0099 for the ionic strength. I just don't understand how to calculate the activity coefficient though. We just learned the concept and I'm confused.
*February 4, 2013*

**Chemistry**

Find the Concentration of CrO4^2- in 0.0033M Ba(NO3)2 saturated with BaCrO4. Include activity coefficients in your solubility-product expression. Ksp of BaCrO4 = 1.17 x 10^-10 I have no idea what to do to solve this :(
*February 4, 2013*

**physics**

Tarzan swings through the jungle by hanging from a vine. At the lowest point of a swing, Tarzan's acceleration is.... A. zero B. not zero C. one cannot be sure whether it's zero or not zero without additional information.
*February 2, 2013*

**math**

Identify the solution(s) of the system of equations, if any. -4x - 4y = 4 4y = -4x - 4 A) no solution B) (0, -1) C) (-1, 0) D) infinitely many solutions
*January 31, 2013*

**Health**

what 2 categories does ecstasy belong to? Name five body organs that can be damaged by drug abuse?
*January 30, 2013*

**physics**

90 g of water at 25C mixed with 50g of another substance at 100C result in 45C what is specific heat of that substance
*January 29, 2013*

**Ms. Sue**

Ms. Sue did you need help on that question? If it's a division problem i could help...the answer to that math problem is...1.50..DON'T BELIEVE ME? WRITE THE ANSWER DOWN AND TAKE IT TO SCHOOL AND SEE IF YOUR CORRECT..just saying!!
*January 28, 2013*

**Calculus/Algebra**

Let the demand and supply functions be represented by p=D(q) and p=S(q), respectively, where p is the price per item in dollars and q is the quantity of items. D(q) = 42-.03q S(q) = .02q -20 Find the equilibrium price. Hint: you will first find the equilibrium quantity (q) and...
*January 28, 2013*

**Calculus/Algebra**

your company produces designer dog-leashes. the marginal costs are $4.50 per leash and each leash is sold for $12.00. You need to produce and sell 75 dog leashes per month in order to break even. Based on this information, what are your monthly fixed costs?
*January 28, 2013*

**Calculus**

Grain is being dropped into a silo from a tall conveyor belt forming a right circular cone with diameter at the base equal to the height. The grain is being added at the rate of 10 cubic inches per second. How fast is the height changing when the height is 80 inches
*January 27, 2013*

**Math **

Give the domain of the following functions. Give your answer in interval notation. a) f(x)= 5x-2/x^2-5x+6 and b) square root of 5-2x
*January 26, 2013*

**Math**

your company produces designer dog-leashes. the marginal costs are $4.50 per leash and each leash is sold for $12.00. You need to produce and sell 75 dog leashes per month in order to break even. Based on this information, what are your monthly fixed costs?
*January 26, 2013*

**Introduction to management**

young innovative or high tech firms often adopt the strategy of ignoring history of attempting to do something radically new.in what ways will this strategy help them?in what ways will this strategy hinder them/
*January 24, 2013*

**ALLIED HEALTH**

If you work in a hospital or doctor's office and assign numeric values to procedures and diagnoses for the purpose of reimbursement, you are a
*January 24, 2013*

**math**

where N is the number of millions of passenger cars in the United States and t is the number of years after 1940. In what year was the number of passenger cars triple the number of cars in 1940?
*January 24, 2013*

**chemistry**

3. Find the molarity of a solution made from 734 g of Li2SO4 and 2.5 L of water
*January 24, 2013*

**algebra**

the number of locust doubles every minute and the skies were full after one hour, when were the skies half full?
*January 22, 2013*

**Chemistry**

How many equivalents are in 1.75L of a 8.2M solution of sulfuric acid.
*January 22, 2013*

**Chemistry**

How many equivalents are in 1.75L of a 8.2M solution of sulfuric acid.
*January 22, 2013*

**Maths**

Find The altitude of a right circular cone of maximum curved surface which can be inscribed in a sphere of radius 'r'.
*January 22, 2013*

**math**

Use the quadratic equation
*January 20, 2013*

**Math**

Sorry to the right
*January 18, 2013*

**Math**

100, 23.55 200, 27.6 998, 65.6 999, 69,1 and you can find points in between to make your graph, It will be an upward graph to the left
*January 18, 2013*

**Math**

#5. If a rancher has one cow with a contagious disease in a herd of 1000, then the time in days “t” for “n” of the cows to become infected is modelled by: t= -5ln((1000-n)/999n where “ln()” stands for natural logarithm function. a) Find the number...
*January 18, 2013*

**Math**

111. Cold Water Survival When a person falls through the ice on a lake, the cold water removes body heat 25 times faster than air at the same temperature. To survive, a person has between 30 and 90 seconds to get out of the water. How long could a person remain in air at the ...
*January 18, 2013*

**Math**

Suppose f is a function with range (-∞,∞) and g is a function with domain (0, ∞). Is it possible that g and f are inverse functions? Explain.
*January 18, 2013*

**Math**

How do I put this into the calculator: 4sqrt-1
*January 18, 2013*

**math**

what is the answer to 6x+4=34
*January 17, 2013*

**Physics**

a) 1336.36 b) 1.04 m/s c) o.o6 m
*January 14, 2013*

**health**

The ________the concentration of HIV in semen or genital fluids, the more likely it is that HIV will be transmitted to a sex partner. A. Lower B. Weaker C. Higher D. All of the above
*January 13, 2013*

**Chemistry**

SnCl4 PF3 H2O
*January 11, 2013*

**Chemistry**

(a) 10^-12*27*(x)^4 replace x with the solubility you have
*January 11, 2013*

**4th grade math**

We know each board is divided into 5 pieces, so the total number of pieces can be represented by 5x. Three-fifths of each board is taken away and 2/5 is left. That's 2/5 of the total number of pieces...2/5(5x). The leftover pieces equal the total length of four boards from...
*January 9, 2013*

**math**

How can 89/100 be writen in a decimal
*January 7, 2013*

**Physics**

An arrow was shot vertically upward at a velocity of 50.0 m/s. What was its velocity after 2.00 seconds?
*January 5, 2013*

**Chemistry**

what is the bond length of sulfur trioxide?
*January 4, 2013*

**health**

i think is c.four pairs
*January 3, 2013*

**health**

There are ________ of muscles that are responsible for chewing movements or mastication. A. Two pairs B. Three pairs C. Four pairs D. Five pairs
*January 3, 2013*

**math**

jenny opened a new loaf of bread to make a sandwiches for her friends. She needed 8 slices out of the 20 slices in the loaf. What percent of the loaf did she use?
*December 29, 2012*

**Astronomy**

Also Assuming that D is much greater than Rm find an approximate expression for the same tidal force, using Newton's approximation method
*December 23, 2012*

**Astronomy**

Suppose the Moon is at a (center-to-center) distance D from Earth. Find an exact expression for the magnitude of the tidal force applied by Earth to our rock of mass m in terms of D, m, the mass of Earth Me (input as M_e), and the lunar radius Rm (input as R_m).
*December 23, 2012*

**Astronomy**

Darwin proposed that the Moon formed far closer to Earth than it is now. Let’s see just how close it could possibly be to Earth and survive. In particular, in the next 4 problems you will find the distance from Earth at which the tidal force due to Earth is sufficient to ...
*December 23, 2012*

**Astronomy**

Consider the same asteroid initially in the asteroid belt at a distance 3 AU from the Sun, and 2 AU from Earth, which collides with Earth. As it falls towards Earth, it acquires kinetic energy (neglect its initial motion) both by being accelerated towards the Sun and towards ...
*December 23, 2012*

**Astronomy**

Consider an asteroid of radius 2 km and density 2,500 kgm3 impacting the Earth. When it collides with the surface its kinetic energy is, to a large extent, dumped into the environment, some as heat vaporizing rock and some as mechanical energy throwing rock to great distance ...
*December 23, 2012*

**Astronomy**

The volume of a ball is given in terms of its radius by V=4π3R3. Use this to find the average density of Saturn, i.e. the mass per unit volume. Use Earth’s mass in kg from the Table of Constants to express your answer in kgm3. Note for comparison that water has a ...
*December 23, 2012*

**Astronomy**

Saturn’s Moon Janus is observed to orbit the planet with period 0.695 days, grazing the planet with an orbital radius only 2.64 times the radius of the planet itself. Use this information to find the mass of Saturn. Express your answer as a multiple of the mass of Earth M...
*December 23, 2012*

**Astronomy**

At opposition, Saturn is observed to subtend an angular radius of 9.16 arcseconds (not including the rings). Use this and the conversion factors in our Table of Constants to find the radius of Saturn in km, rounded to three significant digits.
*December 23, 2012*

**Astronomy**

We observe that oppositions of Saturn repeat every 378 days. Use this information to find the sidereal period of Saturn. Express your answer in years and round to two significant digits.
*December 23, 2012*

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