Wednesday

August 5, 2015

August 5, 2015

Total # Posts: 552

**Probability**

A drawer contains six bags numbered 1-6, respectively. Bag i contains i blue balls and 2 green balls. You roll a fair die and then pick a ball out of the bag with the number shown on the die. What is the probability that the ball is blue? Thank you!
*January 27, 2012*

**Probability**

A screening test for a disease shows a positive test result in 95% of all cases when the disease is actually present and in 20% of all cases when it is not. When the test was administered to a large number of people, 21.5% of the results were positive. What is the prevalence ...
*January 27, 2012*

**Probability**

You toss a fair coin four times. Find the probability of no more than three heads given that at least one toss resulted in heads. Thank you very much!!
*January 27, 2012*

**Geometry **

The ratio of the side lengths of a triangle. Is 2:4:5 and the perimeter is 55 cm. What is the length of the shortest side?
*January 25, 2012*

**Chemistry**

would you multiple 500x0.20 and then divide the amount with 1.30
*January 20, 2012*

**Chemistry**

large dose of vitamin C are supposed to cure the common cold. One commercial over-the-counter product consists of 500-mg tablets that are 20% by weight vitamin C. How many tablets should one take for a 1.30g dose of vitamin C?
*January 20, 2012*

**chemistry**

As the temperature of a gaseous substance is decreased at constant pressure, it will undergo a series of physical changes. Which is the correct sequence of physical states that will be encountered? a.Liquid, solid, gas b.Gas, solid, liquid c.Solid, liquid, gas d.Gas, liquid, ...
*January 20, 2012*

**chemistry**

As the temperature of a gaseous substance is decreased at constant pressure, it will undergo a series of physical changes. Which is the correct sequence of physical states that will be encountered?
*January 20, 2012*

**History**

Discuss why England's North American colonial empire had outstripped those of her European rivals by the end of the seventeenth century?
*January 18, 2012*

**Probability**

Assume that P(A) = 0.4, P(B) = 0.4, and P(A∪B) = 0.7. Find P(A∩B) and P(A complement ∩ B complement).
*January 17, 2012*

**Probability**

In the game of poker, determine the number of ways a straight (five cards with consecutive values, such as A 2 3 4 5 or 7 8 9 10 J or 10 J Q K A, but not all of the same suit) can be picked.
*January 17, 2012*

**Probability**

Twelve children are divided up into three groups, of five, four, and three children, respectively. In how many ways can this be done if the order within each group is not important? Thank you so much!
*January 17, 2012*

**Probability**

Automated chemical synthesis of DNA has made it possible to custom-order moderate length DNA sequences from commercial suppliers. Assume that a single nucleotide weighs about 5.6 X 10^-22 grams and that there are four kinds of nucleotides. If you wish to order all possible DNA...
*January 16, 2012*

**Algebra 2**

From 1990 to 1994, the mail order sales of health products in the United States can be modeled by S = 10t 3 + 115t 2 + 25t + 2505 where S is the sales (in millions of dollars) and t is the number of years since 1990. In what year were about $3885 million of health products ...
*December 30, 2011*

**Algebra 2**

Find the value of c that makes the expression a perfect square trinomial. Then write the expression as the square of a binomial. I didn't really understand what that meant. x^2-23x+c x^2-(2/7)x+c
*December 5, 2011*

**Chemistry**

a sample of gas has the pressure of 1120 mmhg and volume of 2.00 L. if the pressure is changed to 0.155 atm calculate the new volume
*November 29, 2011*

**Calc**

Describe in words the set of all points in R³ that satisfy the following expressions: a) z=0 b) z≥0 c) y≤0
*November 7, 2011*

**s.s**

I just took this exam and the answer is, in fact, cotton yarn.
*November 2, 2011*

**Calc**

Solve: du/dt = (sin t) / (u^2 + 1) So far I got: arctan u = -ln |csc t + cot t| + C I'm not sure where to go from there. Thank you so much for the help!
*October 31, 2011*

**Calc**

How do you take the integral of dy/(y^2 + 4)?
*October 30, 2011*

**Calculus**

What is the limit as t→∞ of L(t)? L(t) = 34 - 32e^(-0.0719t) Thank you so much!
*October 30, 2011*

**Calculus**

Suppose that you follow the size of a population over time. When you plot the size of the population versus time on a semilog plot (i.e., the horizontal axis, representing time, is on a linear scale, whereas the vertical axis, representing the size of the population, is on a ...
*October 30, 2011*

**Calc**

Find the integral from -∞ to -1 of 1/(1+x²) dx. I started working the problem out, and so far I got the lim as z→-∞ of [arctan (-1) - arctan (z)]. I'm a little bit confused exactly what is means when you plug -∞ into z, and how to solve the ...
*October 24, 2011*

**Calculus**

How do you solve the integral from 0 to 1 of x arctan x dx?
*October 24, 2011*

**Calculus**

How do you integrate 3∫(1)/(x²+1)² dx ? Thank you!
*October 19, 2011*

**Calc**

Use substitution to evaluate the indefinite integral: The integral of [ (sq. root (1 + ln x)) ((ln x)/x) dx] Im confused on what i should substitute u and du for. Thank you so much!!
*October 19, 2011*

**Calculus**

Evaluate the indefinite integral: ∫ from 1 to 2 of ln (x²e^x) dx Thank you for your help!!
*October 18, 2011*

**Calculus**

Use either substitution or integration by parts to evaluate the integral: ∫(x+2)/(x²+2) dx Thank you!!
*October 18, 2011*

**Calc**

First make an appropriate substitution and then use integration by parts to evaluate the indefinite integrals: ∫ sinx cos³x e^(1-sin²x) dx I was going to substitute u= 1 - sin²x, but then i got du = ½ sinxcosx - ½ xdx, so im stuck. Thank you ...
*October 18, 2011*

**Calc**

Use integration by parts to evaluate the integral. ∫ from 1 to 4 of (√x) (ln√x) dx Im not really sure what to choose for u and dv. Thank you so much for the help!!
*October 18, 2011*

**Calculus**

F(x) = cos(x) • the integral from 2 to x² + 1 of e^(u² +5)du Find F'(x). When i did this, i got: -2xsin(x)e^((x²+1)² + 5) But my teacher got: -sin(x) • the integral from x² + 1 of e^(u² +5)du + 2xcos(x)e^((x²+1)² + 5) Do ...
*October 17, 2011*

**physics**

To plot the potential energy, simply plug your givens into the equation U=(1/2)kx^2. You should get a parabola that goes to 0 in the center. To determine the turning points of the block, use the law of conservation of energy. You know that Ui+Ki = Uf+Kf since there is no ...
*October 16, 2011*

**Statistics**

The production process of computer parts uses two machines one old & one new. If the old machine is used the probability that the defected part is produced is .13 if the new machine is used the probability that the defective part is produced is .04. moreover, the new machine ...
*October 12, 2011*

**Physics**

F=kx F (tension of the strand)=1.2 pN x (displacement)=26 µm Solve for k, which is the spring constant. You may need to convert your unit measurements, as your answer's unit will come out in pN/µm instead of the standard N/m. (I know this is a little late, but ...
*October 12, 2011*

**Calculus**

A particle moves along the x-axis with velocity v(t) = -(t-3)² + 5 for [0,6]. a) Find the average velocity of this particle during the interval [0,6]. b) Find a time t* ∈ [0,6] such that the velocity at time t* is equal to the average velocity during the interval [0...
*October 10, 2011*

**Calc**

Recall that the acceleration a(t) of a particle moving along a straight line is the instantaneous rate of change of the velocity v(t); that is, a(t) = d/dt v(t) Assume that a(t) = 32 ft/s². Express the cumulative change in velocity during the interval [0, t] as a definite...
*October 10, 2011*

**Calc**

Find the areas of the regions bounded by the lines and curves by expressing x as a function of y and integrating with respect to y. x = (y-1)² - 1, x = (y-1)² + 1 from y=0 to y=2. I graphed the two functions and the do not intersect? Does it matter? Or do I still ...
*October 10, 2011*

**Chem**

Calculate the amount (in moles) of H₂O in 2.00g of Na₂CO₃ ⋅ 10H₂O. Thanks so much!!
*October 8, 2011*

**Chem**

The field of nanotechnology offers some intriguing possibilities, such as the creation of fibers one atom wide. Suppose you were able to string together 1.00 mol Ag atoms, each of radius 144 pm, into one of these fibers by encapsulating them in carbon nanotubes. How long would...
*October 8, 2011*

**Chem**

Calculate the amount (in moles) of Cu²+ ions in 3.00g of CuBr₂. Thank you so much for the help!!
*October 8, 2011*

**Chem**

Epsom salts consist of magnesium sulfate heptahydrate. Write its formula. a) How many atoms of oxygen are in 5.15g of Epsom salts? b) How many formula units of the compound are present in 5.15g? c) How many moles of water molecules are in 5.15 g of Epsom salts? Thank you so ...
*October 7, 2011*

**physics**

if a car can accelerate at 6m/s2, how fast can it accelerate if it is towin an identical car behind it?
*October 5, 2011*

**Calculus**

Assume that a>0. Evaluate the integral from 0 to a of x dx by approximating the region bounded by y=x and the x-axis from 0 to a with rectangles. Use equal subintervals and take right endpoints.
*October 2, 2011*

**History**

Was the answer to this question ever determined?
*September 28, 2011*

**Math**

^^^kids
*September 21, 2011*

**business**

Amyris Biotechnologies was building a plant in 2009 and had synthetic technology to change sugarcane to fuels and chemicals that can be renewed. Their marketing firm was looking for a chemical and a fuel that could be recycled for future use. In 2011, it was decided that the ...
*September 21, 2011*

**Speech**

Oh okay I see now. It's just seemed kind of confusing because I have never had a speech class before.
*September 21, 2011*

**Speech**

Scrapbooking can be fun and release stress and it can be a good memory for yourself and for your loved ones especially if you have kids. You can also make birthday cards and invitations. More than anything scrapbooking can help you be creative. Does that make sense :/?
*September 21, 2011*

**Speech**

My speech can be about anything so I'm going to write and talk about scrapbooking because that is something I enjoy doing.
*September 21, 2011*

**Speech**

Hi I have a speech to present and my professor gave me the outline on how to prepare it but I'm having a hard time setting it up. Is their any kind of way you can help me. Thank you, Erica
*September 21, 2011*

**Acct**

Journalize the following transactions -Recieved cash from investment made by owner,$15000. Recieved cach providing accounting services, $8000. Billed customers on account for providing services, $4000. Paid Advertising expense 400. Recieved cash from customers on account 3500.
*September 20, 2011*

**College English**

I need to write a 700 word essay on what my name means. Can I please get some help!!!
*September 19, 2011*

**English**

It needs to be with my first name which is "Erica". Sorry I am new to this website and I did not see your question.
*September 19, 2011*

**English**

I have to write a 700 word essay on what my name means ????????????? And I need help!!!!
*September 19, 2011*

**Science**

What is the pressure at the bottom of a tube of mercury that is 0.2 m deep? An elephant with a mass of 1000 kg stands on a circus platform that weighs 50 kg. The area of the bottom of the platform is 1.25 m². How much pressure is exerted on the floor beneath the platform...
*September 15, 2011*

**SCIENCE**

When the following are placed in water, for which of them will the buoyant force be more than as its weight? A) an ice cube B) a piece of frozen glycerin C) a gold ring D) a piece of aluminum foil 2. Sometimes when I get in my swimming pool I take a plastic cup filled with ...
*September 15, 2011*

**SCIENCE**

When the following are placed in water, for which of them will the buoyant force be more than as its weight? A) an ice cube B) a piece of frozen glycerin C) a gold ring D) a piece of aluminum foil 2. Sometimes when I get in my swimming pool I take a plastic cup filled with ...
*September 15, 2011*

**Science**

thanks so much
*September 11, 2011*

**Science**

A satellite orbiting at an elevation of 3200 km does what a) Stays beyond the earth's gravity, which is why it stays up there. B) in an elliptical orbit, since its speed is less than the escape velocity. C) Falling toward earth with an acceleration equal to g. D) Falling ...
*September 11, 2011*

**Algebra**

5(2n + 4) - 3(4n - 6) = 2(20 - n) I solved this equation and this is what I got. 10n + 20 - 12n + 18 = 40 - 2n -2n + 38 = 40 -2n 38 ≠ 40 What does this mean? Thank you!
*August 31, 2011*

**Chemistry**

A mixture of gases at 760.0 torr contains 35.0% nitrogen, 22.0% oxygen , and 43.0% carbon dioxide by volume. What is the pressure of the carbon dioxide gas in torr?
*August 19, 2011*

**Greek**

The Greek base HELI- means?
*July 19, 2011*

**anatomy and physiology 1**

which membrance surround and protect the vital organs in the chest cavity?
*July 15, 2011*

**anatomy and physiology 1**

give examples of the various tissue types that exist in your arm. please help me test monday.
*July 15, 2011*

**anatomy and physiology 1**

describle two vision disorders that cause abnormal eyeballshape.
*July 15, 2011*

**algebra II**

Simplify: a^4-b^4/a-b
*July 3, 2011*

**algebra II**

Simplify: (3c^2)(-6cd)^-2
*July 3, 2011*

**physics**

Find the final velocity of the two balls if the ball with velocity v2i = -19.5 cm/s has a mass equal to half that of the ball with initial velocity v1i = +26.8 cm/s. PLEASE HELP!! i have tried so many different ways and can't seem to get the answer
*June 2, 2011*

**physics **

Find the final velocity of the two balls if the ball with velocity v2i = -19.5 cm/s has a mass equal to half that of the ball with initial velocity v1i = +26.8 cm/s.
*June 2, 2011*

**calculus**

3. A deposit of ___(i)___is made into an account paying an interest rate of 5% compounded annually. How many annual payments of ___(iii)___can be made from this account? a) (i)$100,000 (ii)$10,000 b) (i)$200,000 (ii)$20,000 c) (i) 10x (ii) x d) (i) 10x (ii) x at r% compounded ...
*June 1, 2011*

**global history**

the wealth that enabled the Italian city-states to lead in the development of Renaissance arts was derived mainly from? a)the quantities of gold and silver brought back to Italian explorers b)concentration of riches in the hands of the king and his court c)their participation ...
*May 31, 2011*

**physical science**

you are standing on a street corner, and you hear a fire truck approaching. does the pitch of the siren stay constant, increase, or decrease as it approaches you? does the pitch of the siren stay constant, increase, or decrease as it moves away?
*May 23, 2011*

**stats**

A company with a large fleet of cars found that the emissions systems of 18 out of the 65 randomly selected cars they tested failed to meet pollution control guidelines. Is this strong evidence that more than 20% of the fleet might be out of compliance? Test the appropriate ...
*May 11, 2011*

**Calc**

To what limit does the sequence Sn = (3+n) /3^n converge as n approaches infinity?
*May 3, 2011*

**Calc**

How do you know what shape the graph in the xy-plane represented by x=3sin(t) and y=2cos(t) is?
*May 3, 2011*

**calc**

The rate that an object cools is directly proportional to the difference between its temperature ( in Kelvins) at that time and the surrounding temperature (in Kelvins). If an object is initially at 35K, and the surrounding temperature remains constant at 10K, it takes 5 ...
*April 25, 2011*

**Calc**

A particle moves along a path described by x=cos³t and y=sin³t. The distance that the particle travels along the path from t=0 to t=π/2 is... Thank you!
*April 25, 2011*

**calc**

If f(x)= (3x)^(3x), then f'(x) = ? Thank you!
*April 25, 2011*

**Calc**

What is the volume of the solid generated by rotating about the y-axis the region enclosed by y=sinx and the x-axis, from x=0 to x=π? Thank you for your help!!
*April 25, 2011*

**calc**

If a particle moves in the xy-plane so that at time t>0 its position vector is (e^(t²), e^(-t³)), then its velocity vector at time t=3 is...? Thanks so much!
*April 25, 2011*

**Calc**

Find the integral from 1 to 0 of arcsin(x)dx Thank you!
*April 25, 2011*

**Calc**

Use differentials to approximate the change in the volume of a cube when the side is decreased from 8 to 7.99 cm. (in cm^3) Thank you so much!!
*April 25, 2011*

**Calc**

Use differentials to approximate the change in the volume of a cube when the side is decreased from 8 to 7.99 cm. (in cm^3) Thank you so much!!
*April 25, 2011*

**Calc**

What is the limit as x approaches infinity of 4xsin(1/x)? Can you also show me how you get the answer? Thank you so much!!
*April 25, 2011*

**goverment**

For the first eleven years of its existence, the United States was a _____.
*April 12, 2011*

**macroeconomics**

a description of a specific macroeconomic phenomenon or event and how it has impacted you
*March 30, 2011*

**hcs 341**

How can an organization forecast future staffing needs in order to maintain consistent staffing levels?
*March 18, 2011*

**social studies**

Christopher Columbus' treatment of Native Americans can BEST be described as friendly, peaceful but not friendly, violent& hostile,or fair?
*March 11, 2011*

**Chemistry**

What is the percentage of potassium chloride to oxygen?
*March 7, 2011*

**Chemistry**

What is the percentage of potassium chloride to oxygen?
*March 7, 2011*

**Calc**

I have to find the integral of 1/(sq. rt. of (4x-x²)) dx. I know I have to complete the square of the denominator, but im confused on how that process works when im only given 4x-x². Could you demonstrate how to complete the square for that equation? Thank you so much!
*February 22, 2011*

**Calc**

The line y = mx+b with b≥2 is tangent to the graph f(x) = -2(x-2)² + 2 at a point in the first quadrant. What are all possible values of b?
*February 22, 2011*

**Calc**

If dy/dt = 2y/(t(t+2)) for t>0 and y = 1 when t = 1, then when t = 2, y = ?
*February 22, 2011*

**Calc**

A rectangle is to be inscribed in a semicircle of radius 8, with one side lying on the diameter of the circle. What is the maximum possible area of the rectangle?
*February 22, 2011*

**calc**

If dy/dx = xy - y^2 and y(1) = 3, then y (2) = ?
*February 22, 2011*

**Calc**

If n is a positive integer, find the limit as n approaches +∞ of 1/n(sin (π/n) + sin (2π)/n + ... + sin (nπ)/n)
*February 21, 2011*

**Calc**

Let f(x) = x^3 - 7x^2 + 25x - 39 and let g be the inverse function of f. What is the value of g'(0)?
*February 21, 2011*

**Calc**

If the substitution u=x^2 + 1 is made, then the integral from 0 to 2 of [(x^3)/(x^2 + 1)]dx = ? Thank you for your help!
*February 21, 2011*

**chemistry**

at 327 degrees C, the equilibrium concentrations are [CH3OH]=0.15M, [CO]=0.24M, and [H2]=1.1M for the reaction: CH3OH(g)<-->CO(g)+2H2(g) Calculate Kp at this temperature
*February 16, 2011*

**Calc**

Find the indefinite integral. Integral of [1/(4+3x²)]dx Thank you so much for your help!
*February 16, 2011*