Tuesday

September 30, 2014

September 30, 2014

Total # Posts: 596

**Chemistry, HELP!!**

a) If the volume of a flask is 165 mL and the mass of the vapor in the flask is 0.2136 grams, what is the density of vapor in the flask? b)If the temperature of the vapor is 25 degrees Celsius, what is the molecular weight of the vapor? (Assume the gas pressure to be 1.00 atm.)
*September 23, 2014*

**Chemistry, empirical formula**

Determine the empirical formula for the following compounds with these compositions (by mass): a) Cr 47.7% F 52.3% b) Na 42.1% P 18.9% O 39.0%
*September 23, 2014*

**Math**

I understand that part, but what about the subintervals
*September 11, 2014*

**Math**

consider the polynomial (x-a)(x-b)and the real number line Identify the points on the line where the polynomial is zero. In each of the three subintervals of the line, write the sign of each factor and the sign of the product.For which values does the polynomial possibly ...
*September 11, 2014*

**physics**

a large aircraft accelerates sown the runway for a distance of 3000m before leaving the ground. It then climbs at a steady 3 degree angle. After the plan has travelled 4000m along this new trajectory, how high is it and how far horizontally is it from its initial position?
*September 9, 2014*

**Math**

297x^2 - 167x - 100 Can someone help me find the roots of this
*September 8, 2014*

**statistics**

Use the given sorted values below which are the numbers of points scored in the Super Bowl for a recent period of 24 years. 36 37 37 39 39 41 43 44 44 47 50 53 54 55 56 56 57 59 61 61 65 69 69 75
*August 10, 2014*

**Math**

One model of Earth's population growth is , where t is measured in years since 1990, and P is measured in billions of people. Which of the following statements are true?
*August 6, 2014*

**math**

121
*July 17, 2014*

**Algebra**

Thank you for helping Ms. Sue.
*June 12, 2014*

**Algebra**

A rectangular Persian carpet has a perimeter of 212 inches. The length of the carpet is 24 inches more than the width. What are the dimensions of the carpet?
*June 12, 2014*

**Math**

At a carnival, Linda bought packs of tickets each. She has used of the tickets so far. How many tickets does she have left?
*June 9, 2014*

**math Question**

Find an equation that models a hyperbolic lens with a=12 inches and foci that are 30 inches apart. assume that the center of the hyperbola is the origin and the transverse axis is vertical.
*May 19, 2014*

** algebra**

The first angle of a triangle is 23° more than the 2nd angle. The 3rd angle of a triangle is 6 times the 2nd angle. Use X to represent the unknown value
*May 11, 2014*

**Math**

6 because you have to change mixed numbers into improper fractions do 1 1/2 becomes 3/2 and 4x(3/2) = 6.
*April 29, 2014*

**Chemistry**

The part of an electrochemical cell that carries electrons to a reacting ion is a(n) (1) cathode (2) anode (3) electrode (4) electrolyte
*April 22, 2014*

**Global History**

Vietnam was not originally what France primarily wanted. Explain the value of Vietnam at the time. The time period is around the Vietnam war!
*March 23, 2014*

**MATH**

A photograph has been enlarged to three times its previous size. By what percentage has the size of the photograph increased?
*March 8, 2014*

**Chemistry**

Compare the physical and chemical properties of acids and bases.
*March 4, 2014*

**Chemistry**

Element P electron configuration is 2-8-8-1 Element Q electron configuration is 2-8-18-7
*February 25, 2014*

**Health**

Explain how homelessness is a health-related social issue.
*February 24, 2014*

**Chemistry**

Explain how a person bailing out a row boat with a leak could represent a state of physical equilibrium.
*February 12, 2014*

**math**

Input output table like this 0 in no output 2/3 in 17/6 out 11/4 in ? Out 3 in 13/3 out - in 13/2 out ?
*January 14, 2014*

**Science**

Thanks you very very much !
*January 6, 2014*

**Science**

How are are the viruses, bacteria, fungi, and protists similar? are the all living things or only visisble to through a microscope or infectious diseases??
*January 6, 2014*

**social studies**

Which of the following statements about the natural resources of the United States is most accurate? A. The many agricultural resources of the United States have made up for its lack of other resources. B. U.S. industry and agriculture have prospered because America has many ...
*December 23, 2013*

**LANGUAGE ARTS**

what is number 2 and 3
*December 18, 2013*

**5th Grade Math**

Complete the knput output table write the rule. 0 in - out 3/2 in 17/6 out 11/4 in - out 3 in 13/3 out - in 13/2 out i don t understand
*November 26, 2013*

**Physics**

A baton twirler tosses a baton into the air with an initial angular velocity of 2 rev/s (revolutions per second). The baton undergoes a constant angular acceleration of -.015 rev/s^2 while in the air, and its angular velocity when she catches it is .8 rev/s. Determine the ...
*November 7, 2013*

**Calculus II**

Wow this problem is easier than I thought it was. Thanks.
*November 3, 2013*

**Calculus II**

A cable that weighs 1.5 lb/ft is used to lift 700 lb of coal up a mineshaft that is 400 ft deep. Find the work done.
*November 3, 2013*

**Thomas Nelson **

What is chromatin?
*October 31, 2013*

**Chemistry Hess's Law **

(1) 2 Ni(s) + O2 (g) --> 2NiO(s) delta H= -479.4 kJ (2) Ni(s) + Cl2(g) --> NiCl2(s) delta H= -305.3 kJ Using equations 1 and 2 and Hess's Law, determine the amount of moles Nickel (ii) Chloride that was combusted given the following: volume = 15.45 L pressure = 2.29 ...
*October 23, 2013*

**math**

Verify the given linear approximation at a = 0. Then determine the values of x for which the linear approximation is accurate to within 0.1. (Enter your answer using interval notation. Round your answers to three decimal places.)
*October 20, 2013*

**Math**

Solve for a and b. 2a-ai-5b=0, a-2b-bi=0. Where i is complex number.
*September 28, 2013*

**Math**

Solve x^2+1=0.
*September 28, 2013*

**Math**

Solve x^2+1=0.
*September 28, 2013*

**social studies**

According to the majoritarian model of democracy, what role should public opinion play?
*September 25, 2013*

**physics**

A bullet was fired horizontally from the top of a 1.5x10^2 m tall tower at 2.8x10^2 m/s. Determine its speed on impact with the ground below.
*September 23, 2013*

**math**

Use the formula t = (0.25) s1/2 to find the time t in seconds it will take a stone to drop a distance s of 200 feet. Round your answer to the nearest tenth of a second.
*August 20, 2013*

**ap chemistry**

How would you find the remaining mass of the excess reagent?
*August 1, 2013*

**physics**

A rocket is used to place a satellite in orbit about a planet. The velocity of the satellite is 534 m/s and the radius of orbit is 1.21×108 m. What is the mass of planet?
*July 29, 2013*

**macroeconomics**

b. Now suppose that the gross national debt initially is equal to $2.5 trillion and the federal government then runs a deficit of $100 billion: i. What is the new level of gross national debt? ii. If 100 percent of the deficit is financed by the sale of securities to the ...
*July 28, 2013*

**Finite math**

The manager of a money market fund has invested $4.2 million in certificates of deposit that pay interest at the rate of 5.4%/year compounded quarterly over a period of 5 years. How much will the investment be worth at the end of 5 years?
*July 28, 2013*

**fnite math**

Juan invested $24,000 in a mutual fund 5 years ago. Today his investment is worth $34,616. Find the effective annual rate of return on his investment over the 5-year period.
*July 28, 2013*

**physics**

I solved and got 0.399m and that was wrong, so I don't know...
*July 20, 2013*

**physics **

I'm really confused on this problem too. Does anyone understand how to do it?????????
*July 20, 2013*

**Accounting**

85,000
*July 14, 2013*

**social question**

how much gas do you use to travel 172 miles at 4.00 a gallon.
*July 2, 2013*

**social question**

how much gas do you use to travel 172 miles at 4.00 a gallon.
*July 2, 2013*

**Physics**

Two charges +q and −q are separated by a distance d=50 cm. The electric field lines for this system form the the well-known pattern showed in the figure below. Consider two lines L1 and L2 lying on the same plane and leaving the positive charge at α=±45∘...
*July 1, 2013*

**Math**

Six people are playing Secret Santa for Christmas. They will each give one gift to someone, and each receive one gift from someone. They are not allowed to receive their own gift. How many different ways are there to exchange gifts?
*July 1, 2013*

**Math**

Find an equation for the line that contains the points (2, -3) and (6, 9).
*June 2, 2013*

**Calculus**

ç1 0 x^2dx=1/3. Use this and the properties of integrals to evaluate ç1 0 10−2x^2dx
*May 12, 2013*

**Calculus**

A piece of wire 40 m long is cut into two pieces. One piece is bent into a square and the other is bent into an equilateral triangle. How should the wire be cut so that the total area enclosed is a maximum= minimum= Find the length of the wire used
*May 7, 2013*

**Chemistry**

For a solution of 3.3 M H2CO3 (Ka = 4.4 × 10-7), calculate: (a) [H+] ____?______M (b) pH _____??______ (c) percent ionization ______?______%
*April 30, 2013*

**Math**

What is 1 5 of 20
*April 25, 2013*

**Urgent math**

If f(x, y, z)=sin(3x-yz), where x=e^(t-1), y=t^3, z=t-2, what's df/dt(1)? x(1)=1 y(1)=1 z(1)=-1 df/dt=(3cos(3x-yz))(e^(t-1))+(cos(3x-z))(3t^2)+(cos(3x-y))(1) I seriously need help on this and tell me the answer and show your work through steps. Thanks.
*April 20, 2013*

**Algebra**

A chain store manager hs been told by the main office that daily profit, P, as related to the number of clerks working that day, x, according to the functions P=-25x^2 + 300x. What number of clerks will maximize teh profit, and what is the maximum possible profit?
*April 18, 2013*

**Calculus**

Estimate ç 6 0 6−x^2 dx using 3 right rectangles
*April 18, 2013*

**Calculus**

Estimate ç 6 0 6−x^2 dx using 3 left rectangles.
*April 18, 2013*

**physics**

An aluminum wing on a passenger jet is 38 mlong when its temperature is 23°C.At what temperature would the wing be 2 cm (0.02 m) shorter?
*March 18, 2013*

**Chemistry**

A compound containing only carbon, hydrogen and oxygen is subjected to elemental analysis. Upon complete combustion, a .1804g sample of the compound produced .3051g of CO2 and .1249g of H2O. What is the empirical formula of the compound?
*March 14, 2013*

**Chemistry**

What is the wavelength of an electron traveling at 7.59% of the speed of light?
*March 14, 2013*

**Chemistry**

How many valance electrons are there in [(C2H5)4N]+ ?
*March 14, 2013*

**Chemistry**

What is the C-C-H bond angle in the molecule H2CCO?
*March 14, 2013*

**Chemistry**

What type of reaction will occur when an aqueous solution of lithium chloride is mixed with an aqueous solution of ammonium sulfate?
*March 14, 2013*

**Analytical Chemistry**

Serum taken from a patient being treated with lithium for manic-depressive illness was analyzed for lithium concentration. A reading of 291 units was obtained for the intensity of the 671 nm red emission line. Then 1.00 mL of a 11.7 mM Lithium standard was added to 9.00 mL of ...
*March 5, 2013*

**Physics**

Dry air will break down if the electric field exceeds about 3.0 × 106 V/m. What amount of charge can be placed on a capacitor if the area of each plate is 6.7 cm2?
*February 28, 2013*

**physics**

The two plates of a capacitor hold +3200 µC and -3200 µC of charge, respectively, when the potential difference is 700 V. What is the capacitance?
*February 28, 2013*

**Calculus I, differentiation**

The number, N, of people who have heard a rumor spread by mass media by time, t, is given by N(t)=a(1−e−kt). There are 6 million people in the population, who hear the rumor eventually. If 5% of them heard it on the first day, find the percentage of the population ...
*February 24, 2013*

**Physics**

Betty weighs 427 N and she is sitting on a playground swing seat that hangs 0.22 m above the ground. Tom pulls the swing back and releases it when the seat is 0.88 m above the ground. The acceleration of gravity is 9.8 m/s2. How fast is Betty moving when the swing passes ...
*February 20, 2013*

**invest**

You budget $100 for parking each month. Each day you use the downtown parking lot, it costs you $5. Write a rule to represent the amountof money left in your monthly budget as an arithmetic sequence. How much money is left in your budget after you have used the downtown ...
*February 17, 2013*

**Algebra**

invest $ 3000 and save $100 each month. Write a rule to represent the total amount of money invest into your account as arithmetic sequence. How much money will you have invested after 12 month?
*February 17, 2013*

**Physics**

A cannon is mounted on a truck that moves forward at a speed of 5 m/s. The operator wants to launch a ball from a cannon so the ball goes as far as possible before hitting the level surface. The muzzle velocity of the cannon is 50 m/s. What angle from the horizontal should the...
*February 17, 2013*

**Differential Equations**

y'=2x+y. Find a solution whose graph is also an isocline.
*February 14, 2013*

**Physics**

A cannon is mounted on a truck that moves forward at a speed of 5 m/s. The operator wants to launch a ball from a cannon so the ball goes as far as possible before hitting the level surface. The muzzle velocity of the cannon is 50 m/s. What angle from the horizontal should the...
*February 13, 2013*

**Life oreintation**

What according to the basic conditions of employment act applies with regard to the contraventions
*January 29, 2013*

**Physics PLEASE HELP!**

Youre summing forces so mg is force due to gravity g=9.8 There are three forces, kx the spring mg gravity and qE the field force
*January 28, 2013*

**Physics**

40.6 m/s 1.3 s -26 degrees
*January 23, 2013*

**World history; HELP**

Didn't you learn to read a textbook instead of asking online for homework answers?
*January 18, 2013*

**Psychology**

Human relations are universal, but those defined as basic or primary are: a. the same from culture to culture b.defined differently in different cultures
*January 11, 2013*

**Calculus **

Use the graph of f(x)=x^2/(x^2-4) to determine on which of the following intervals Rolle's Theorem applies. A) [0, 3] B) [-3, 3] C) [-3/2, 3/2] D) [-2, 2] E) None of these
*December 23, 2012*

**Urgent Math**

f(x)=(x+2)^3-4. The point (-2, -4) is which of the following? A) An absolute maximum B) An absolute minimum C) A critical point but not an extremum. D) Not a critical point E) None of these I think the answer is C, am I right?
*December 23, 2012*

**Math**

Use the definition of logarithm to simplify each expression. (a) log6b (6b) (b) log9b ((9b)^5) (c) log10b ((10b)^-8)
*December 23, 2012*

**Math**

Evaluate the following expression. (Note, I'm not sure how to write this in mathematical form)but the P is slightly raised above both numbers. 210 P 1 = ______
*December 23, 2012*

**Math**

Find the probability whose odds against are given in the problem. Odds against are 5 to 7. Answer is ________.
*December 23, 2012*

**Math**

From a survey of 200 college students, a marketing research company found that 130 students owned iPhones, 70 owned cars, and 60 owned both cars and iPhones. (a) How many students owned either a car or an iPhone (but not both)? _______students (b) How many students do not own ...
*December 23, 2012*

**Math**

Thank you Ms. Sue!
*December 23, 2012*

**Math**

The math problem is set up as a fraction in parenthesis 6 over 4. Evaluate the expression (6/4)
*December 23, 2012*

**Urgent Math**

Let f"(x)=4x^3-2x and let f(x) have critical values -1, 0, and 1. Determine which critical values give a relative maximum. A)-1 B)0 C)1 D)-1 and 1 E) none of these
*December 22, 2012*

**Physics**

I still don't understand part (a). I know that cos^2(90)=0 but how did you get to the answer of 2 sheets?
*December 21, 2012*

**Physics**

I don't really know. I did ln(1/100)=-4.605 and ln(cos(90)^2)=-1.605 and 4.605/1.605=2.869. The answer for part (a) should be 2 but 2.869 is closer to 3 so am I doing anything wrong?
*December 21, 2012*

**Physics**

We want to rotate the direction of polarization of a beam of polarized light through 90 degrees by sending the beam through one or more polarizing sheets.(a) What is the mini-mum number of sheets required? (b) What is the minimum number of sheets required if the transmitted ...
*December 21, 2012*

**Physics**

We want to rotate the direction of polarization of a beam of polarized light through 90 degrees by sending the beam through one or more polarizing sheets. (a) What is the mini-mum number of sheets required? (b) What is the minimum number of sheets required if the transmitted ...
*December 20, 2012*

**Physics **

A small spaceship whose mass is 1.5x10^3 kg (include-ing an astronaut) is drifting in outer space with negligible gravitational forces acting on it. If the astronaut turns on a 10 kW laser beam, what speed will the ship attain in 1.0 day because of the momentum carried away by...
*December 20, 2012*

**Physics**

Some neodymiun-glass lasers can provide 100 TW of power in 1.0 ns pulses at a wavelength of 0.26 um. How much energy is contained in a single pulse?
*December 19, 2012*

**Physics**

A spaceship at rest in a certain reference frame S is given a speed increment of 0.50c. Relative to its new rest frame, it is then given a further 0.50c increment. This process is continued until its speed with respect to its original frame S exceeds 0.999c. How many ...
*December 16, 2012*

**Physics**

Thank you!
*December 15, 2012*

**Physics**

A 5.00-grain aspirin tablet has a mass of 320 mg. For how many kilometers would the energy equivalent of this mass power an automobile? Assume 12.75 km/L and a heat of combustion of 3.65x10^7 J/L for the gasoline used in the automobile.
*December 15, 2012*

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