Thursday
March 26, 2015

Posts by Nancy


Total # Posts: 719

Chemistry- rate laws
CH3CHO decomposes into methane gas and carbon monoxide gas. This is a 2nd order reaction. Rate of decomposition at 140 degrees Celsius is .10M/s when the concentration of CH3CHO is .010. What is the rate of the reaction when the concentration of CH3CHO is .50M? Have not been ...
September 18, 2012

math
1-How many three digit numbers are even? 2-how many three digit numbers are not even and do not divide by 5 ?
September 16, 2012

math
How many three-digit numbers are even ?
September 16, 2012

math
How many four-digit numbers divide by 5 ? Note:0001 is considered a 1-digit number .
September 16, 2012

math
Suppose a license plate requires three letters ,followed by three digits.how many license plates are there if the letters are all different and the digits are all different
September 16, 2012

chemistry
Determine the final temperature when 10g of steam at 100C mixes with 500g of water at 25C. I have 4.184x 10(100-x) + 40700 x 10= 500 x (x-25) x 4.18. The book has 10/18 instead of 10 on left hand side of equation. Why??
August 18, 2012

chemistry
Find the number of disintegrations per minute emitted by 1.1 mol of 232-Th in 1 min. The half-life of 232-Th is 1.4 x 1010 year I was able to do this with the following technique: 1.1 x 6.022 x10^23 =6.62x10^23 1.4x10^10=7.358x10^15 minutes I think then it is 6.62x10^23 x 7....
August 2, 2012

algebra/logs
I don't understand this problem: (1/2)n = 0.015625 n log 0.5 = log 0.015625 n = log 0.5 / log 0.015625 n = 6 When I plug log .5 into the calculator it gives .3010 and when I plug .15625 to the calculator it is -1.806 and that would be -.3010/-1.806 =.1666. How is the ...
August 2, 2012

algebra
solve the equation 5x^2=19x+4 X=
July 24, 2012

algebra
Find the number of decibels for the power of the sound. round to the nearest decibel. A rock concert, 5.35x 10^4 watts/cm^2
July 24, 2012

chemistry
I think I've got it by looking through the balanced equation. It is just hard to understand the NA repeated twice on the right side of the equation.
July 1, 2012

chemistry
you are right. It is Na2HPO4 + HI ==> NaI + NaH2PO4 for which the net ionic equation is HPO4^- + H^+ ==> H2PO4^- Can you explain how to get this, though? any steps would be helpful.
July 1, 2012

chemistry
I need to derive a net ionic equation after balancing: NA2PO4 (2-) +HI =? what I have so far is NA2Po4 +2HI = 2NAI +H3PO4 I can't get any farther but the answer is HPO4 (2-) +H =H2PO4 can someone help me with the steps?
July 1, 2012

finance
BBA307: Finance Exercise 8A Assignment 8.1 Assignment 8.1: Capital Budgeting Application You have just graduated and one of your favorite courses was Financial Management. While you were in school, your grandfather died and left you $1 million. You have decided to invest the ...
June 28, 2012

geometry
the arc length of AB is 2^pi ft. find the radius of the circle ABC=43 degree. round your answer to the nearest hundredth.
June 25, 2012

Geometry
I need help on a problem thats on formula for circumference. A circle has a circumference of 36 cm. find it's radius .but it says give an exact answer in simplest form and it says enter pi for the symbol of pie .
June 22, 2012

chemistry
You don't need to do a balanced equation for this one. 2.5x =.100(.50) x=.020 this would be 20 ml the formula is Liters x Molarity =Moles so 2.5Molar times x # of liters =.100 x.50 answer is 20ml
June 19, 2012

chemistry
molarity x liters = moles you would need to know how many moles or liters to use the above formula. How much NAOH are you being asked to find molarity for?
June 18, 2012

Chemistry
I don't know if I should be posting this on a new session or just the old one; I asked it yesterday and I have not seen a reply I have: the half life of U-238 is 4.5 x 10^9 yr. A sample of rock of mass 1.6g produces 29 disintegrations per second. find percent by mass of U-...
June 18, 2012

math
actually David is right. I forgot the decimal place from the 22 so it is 54.5 amps
June 17, 2012

math
E= I x R is the formula the answer is .5454 I=amperes R=ohms E=volts 12volts/22
June 17, 2012

chemistry
I have: the half life of U-238 is 4.5 x 10^9 yr. A sample of rock of mass 1.6g produces 29 disintegrations per second. find percent by mass of U-238 in rock. I have 4.5x 10^9x60x60x365x24=1.419x 10^17= .693/1.419 x10^17 =4.883x10^-18 =rate 1.6/238=.006722 x 6.022 x10^23=4.048 ...
June 17, 2012

Chemistry
2Na + 2H2O → H2 + 2NaOH is the balanced equation. from that, .113 mole/2=.0565 x -368 = -20.79kj or 20.79 kj heat is created in the reaction.
June 17, 2012

chemistry
Yes this does help! Thanks!
June 17, 2012

chemistry
A 1.50 liter gas sample at 745mm HG and 25 celsius contains 3.55% radon by volume radon-220 is an alpha emitter with a half life of 55.6 seconds. how many alpha particles are emitted in 5 minutes by this sample? I got an answer 1.59x10^19 I started at 745/760=.980263 then ....
June 17, 2012

Chemistry
X-rays have a wavelength in the range of 0.01 to 10 nanometers.. That would be a wavelength of up to 10 billions of a meter
June 17, 2012

Algebra 2
An ice-cream parlor sells sundaes with 3 different types of ice-cream and 4 different toppings. They have 8 flavors of ice-cream and 10 toppings for their customers to chose from. what is the probability that a customer orders a sundae including the toppings of whipped cream, ...
May 24, 2012

math
To turn a %number into a decimal just move the decimal over two spots from the whole number. So, for example 100% would be 1, or 33 1/3 would be .33333 which is 1/3 of 100%. The 1/3 part turns into .33 because 1/3 of a dollar is 0.33 cents. another example would be 25% is 0.25...
May 22, 2012

chemistry
Thank you Dr.Bob for your speedy reply-I also tutor in other subjects, but chem. is my nemesis.
May 15, 2012

English
"Spielberg's ability to communicate visually in the media of film is no doubt matched by his versatility as a public speaker." take it from there. giving examples of the oral topics he might cover as expressed already in his incredibly varied kinds of films, from...
May 15, 2012

English 2 Animal Farm
He simply represents a worldly point of view rooted in negativism based on experience (vs. the Intellect, the Evil, the populist)
May 15, 2012

chemistry
How many joules to vaporize 1.5 L of H2O at 19 degrees Celsius?
May 15, 2012

English
Note the individual words that have common associations:stagger, fall. note the repetition of vowel sounds within the lines to strengthen the mood.note how short the lines and words are, to mimic the nature of the scenery--harsh, barren, ie., tough.
May 14, 2012

Biology
I think that you calculate algebraically: since 400% is quadruple, divide that by 5.5% to get the # of years
May 14, 2012

Algebra 2
a hyperbola is centered at (3,7). The vertices are (9,7) and (-3,7). The slopes of the aymptotes are m==/-5/6. Enter the equation of the hyperbola in the form: (x-h)^2/a^2-(y-k)^2/b^2=1
May 14, 2012

Algebra 2
Soo the equation is 25y^2-9x^2-200y-36x+139=0 and for the center is got (2,4) and the vertices I got (2,7) and (2,1) But i cant figure out how to find the slopes of the asymptotes and it wants the answer is reduced fraction please explain
May 13, 2012

Writing
My own opinion on this issue is that it is past time for the government to take some responsibility in legislating the food products/garbage that is so heavily marketed through advertising--the detrimental effects of eating junk foods that lead to cancer, heart disease, ...
May 12, 2012

chemistry
I think that the base always contains hydroxide, aka OH; the original components were water mixed with an ammonium compound ( NH2)Check the chemistry reference tables too, which have tables that identify the bases and acids.
May 12, 2012

poems
Sammy sold seashells by the shoreline on oysters and mussels he did dine when the tide rolled in he went for a swim and forgot about selling those seashells
May 12, 2012

Algebra 2
A package with square ends has combined length and girth(girth is perimeter of a cross section) of 120 in. The surface area of the entire package is 3600 sq. in. Determine the dimensions of the package. s in. * s in.* l in. One solution is: 11.08in. * 11.08in. * 75.68in. Find ...
April 29, 2012

Math
a cylinder has a radius of r and a height of h. A rectangular box has a length of r, a width of h and height of h. Their combined volume is V=πr^2h+h^2r If their combined volume is 600 cubic inches and h is 5 inches, solve for the radius(r).
April 29, 2012

Math
the formula for the surface area of a cylinder is: A=2πrh+2πr^2 If the height of the cylinder is 10 inches, and the surface area is 200 sq. inches, determine the length of the radius
April 29, 2012

Algebra
The formula for the volume of a cylinder is: V=πr^2*h If the volume is 432 cubic inches and the height is 8 inches, solve for the length of the radius.
April 29, 2012

algebra2
If an object is thrown vertically upward with an initial velocity of v, from an original position of s, the height h at any time t is given by: h=-16t^2+vt+s (where h and s are in ft, t is in seconds and v is in ft/sec) Solve for t when the object hits the ground. (when h=0) t...
April 27, 2012

Algebra 2
If an object is thrown vertically upward with an initial velocity of v, from an original position of s, the height h at any time t is given by: h=-16t^2+vt+s (where h and s are in ft, t is in seconds and v is in ft/sec) If a rock is dropped from the top of a 200 ft building, ...
April 27, 2012

Algebra 2
A rectangular piece of cardboard has length that is 16 inches more than the width. The area of the cardboard is 297 sq. in. Find the measures of its width and length. Enter width in., length in.
April 26, 2012

Algebra 2
A farmer has 120 ft. of fencing available to enclose 2 adjacent rectangular pens alongside his barn. NO fencing is required along the bard side. He needs to have a total of 930 sq.ft. Determine the width (x) and the combined length of the pens. There are two solutions. One is ...
April 24, 2012

Algebra 2
√3x-4=2√x-5 Solve this equation, if there is more then one answer separate with a comma
April 19, 2012

Algebra 2
x= √3x+12+2
April 18, 2012

Algebra 2
√3x-4=2√x-5 Solve this equation, if there is more then one answer separate with a comma
April 18, 2012

Algebra 2
Solve this equation: √4x+8=6 If there is more then one solution enter with a comma
April 18, 2012

algebra2
evaluate without using a calculator 216 2/3
April 18, 2012

Algebra 2
SIMPLIFY: 3√(63x^5/(72y^6)) Example to enter answer: n√b, enter (b)^(1/n) Example: For 4√3:2, enter 4(2)^(1/3).What is my answer and how do i answer it?
April 17, 2012

Pharmacology
3/100
April 16, 2012

algebra2
How do i enter my answer? so the question is Simplify: √3:(63x^5/(72y^6)) and for my answer i got x√3:(7x^2/(2y^2)) but my work page says: Enter example: For 4√3:(2), enter 4(2)^(1/3) so how do i enter my answer
April 14, 2012

math
at a store you bought 2 pounds of apples and 1 1/3 pounds of grapes. If the store's scale measures to the nearest half pound, what is the range of possible actual weights for the sum of both purchases of fruits.
April 13, 2012

how do i enter my answer
√4:(32x^11y^15)/√4:(2x^3y^-2) for this equation i got =2x^2y^4√4:y and in my worksheet it says enter it: √b, enter sqrt(b). For example: For 4√3 enter 4sqrt(3) so how would i enter my answer
April 13, 2012

Algebra 2
√(21x^2y/(75xy^5) it says on my paper to enter it: √b, enter sqrt(b). For example: For 4√3 enter 4sqrt(3) Please help, I've got 5 wrong! :(
April 13, 2012

Algebra 2
An airplane flies 1050 km with the wind. In the same amount of time, it can fly 750 km against the wind. The speed of the plane in the still air is 200 km/h. Find the speed of the wind.
April 12, 2012

Algebra 2
Name this polynomial by its number of terms and degree.? √29x^6
April 12, 2012

Algebra 2
which property justifies this statement q+(r+s)=(q+r)+s a. communicative property of addition B. distributive property C. Associative property of addition D. identity property
April 12, 2012

Algebra 2
240,000,000x 0.000024/0.005 simplify and convert to scientific notation
April 12, 2012

Algebra 2
Evaluate the expression. 10x^3y^-5z^-2 if x=3, y=2, z=5
April 11, 2012

Algebra 2
which of the following are not polynomials? A. x^4+ πx^3+√2x B. 3x+x^4 C. 4x^3+2x^2+ √x D. 2x^3/5-x/3+π E.x/4-5/x+10
April 10, 2012

Algebra 2
The sum of two numbers is 100. One number is four more than three time the other number. What are the last numbers?
April 10, 2012

Algebra 2
Find (gº f)(-4) f(x)=-x^2+4 g(x)=2x
April 9, 2012

Algebra 2
Find the slope of the line containing these points. (1/8, 1/4) and (3/4, 1/2)
April 9, 2012

Chemistry
Why does equilibrium shift to the left when AgNO3 is added to the equation Co(H20)6 (aq) + 4Cl- (aq) <---> CoCl4 (aq) + 6H2o(l)?
April 8, 2012

statistic
The amount of time a bank teller spends with each customer has a population mean of 3.10 minutes and standard deviation of 0.40 minute. If a random sample of 16 customers is selected, a) what assumption must be made in order to solve parts (b) and (c)? b) what is the ...
April 7, 2012

statistic
The Tite Wire Company manufactures wires for circus acts. It has taken a random sample of 100 pieces of wire and wants to see if the thickness of a batch of wire meets minimum specifications. Assume that the population mean is 0.45 inch, with a standard deviation of 0.03 inch...
April 7, 2012

statistic
The distribution of cash withdrawals from the automatic teller machine at a certain bank has a mean of $500 with a standard deviation of $70. To reduce the incentives for robbery, the bank puts money into the machine every 12 hours and it keeps the amount deposited fairly ...
April 7, 2012

statistic
If 55% of a television viewing population watched a program called ¡§Name that Poem¡¨ one evening, what is the probability that, in a random sample of 100 viewers, less than 50% of the sample watched the program?
April 7, 2012

algebra2
Solve this formula for m. simplify your answer. S=H/m(a-b)
April 5, 2012

Algebra 2
two resistors are connected in parallel. Their resistances are 6 ohms and 10 ohms. What is the resistance, (R), of the combination? R=-----ohms?
April 5, 2012

Algebra 2
A resistor has a resistance of 15 ohms. What size of resistor, (r2), should be connected in parallel with it to obtain a resistance of 7 ohms. Use 1/R=1/r1+1/r2. r2= ohms?
April 5, 2012

Algebra 2
Solve this formula for r. Simplify your answer. E/d=R+t/r Make sure you use parenthesis around any polynomials in the numerator and or denominator.
April 5, 2012

Math
a motorboat can go 24 miles downstream in the same amount of time that it takes to go 12 miles upstream. The boats speed in still water is 12 mph. What is the speed of the river? mi/hr?
April 5, 2012

Chemistry
How do I write the skeleton equation then balance the following (step by step): hydrogen+bromine---> hydrogen bromide
April 4, 2012

statistic homework
If 55% of a television viewing population watched a program called ¡§Name that Poem¡¨ one evening, what is the probability that, in a random sample of 100 viewers, less than 50% of the sample watched the program?
April 4, 2012

statistic solution
The distribution of cash withdrawals from the automatic teller machine at a certain bank has a mean of $500 with a standard deviation of $70. To reduce the incentives for robbery, the bank puts money into the machine every 12 hours and it keeps the amount deposited fairly ...
April 4, 2012

statistic
The Tite Wire Company manufactures wires for circus acts. It has taken a random sample of 100 pieces of wire and wants to see if the thickness of a batch of wire meets minimum specifications. Assume that the population mean is 0.45 inch, with a standard deviation of 0.03 inch...
April 4, 2012

Algebra 2
(4x^3-3x^2+7x)/(x+1/2) Quotient and remainder
April 1, 2012

Algebra 2
(3x^4-5x^3+7)/(x+1)
April 1, 2012

Algebra 2
(3x^3+4x^2-7x+6) / (x-3) quotient and remainder
March 31, 2012

International Finance
What is an AA curve?
March 24, 2012

Algebra 2
(2x^3-x^2-48x+15)/(x-5) Divide and find the quotient and remainder?
March 23, 2012

Algebra 2
(4x^3-4x^2-x-3)divided by(2x^2-3)
March 22, 2012

Algebra 2
(4x^4-4x^2-x-3)divided by(2x^2-3) quotient an remainder?
March 21, 2012

Algebra 2
(3x^4-2x^3+4x-5) divided by (x^2+4) quotient and remainder
March 21, 2012

Algebra 2
(4-3/x^4)/(5+2/x3) Simpify, Leave in factored and reduced form.
March 20, 2012

Algebra 2
(5+3/x^2y)/(3+x/x^3y) Simplify. Leave in factored and reduced form. Put () around polynomials in numerator and denominator
March 20, 2012

algebra2
(4/y^2-1/y^3)/(2/y+3/y^2) Simplify. Leave answers in factored and reduced form. Put () around the polynomials on numerator and denominator.
March 19, 2012

Algebra 2
x^2/x^2+3x-10 - 1/x^2+8x+15 Simplify Leave in factored form and put () around polynomials
March 17, 2012

Algebra 2
(5y+5)/(y^2^+7y+6)*(y^2^+4y-12)/(y^2^+3y-10) Simplify Leave answer in factored form. Keep () around binomial factors.
March 16, 2012

CHEMISTRY
HOW MUCH 1 MOLE HCL IS REQUIRED TO MAKE 250ML OF 0.1 MOLE HCL?
March 14, 2012

Sociological
Using the sociological perspectives: functionalism, conflict, symbolic interactionism and feminism, show how Facebook has made an impact on today's technologically-advanced society.
March 4, 2012

Math
a chemist has an 18% acid solution and a 36% acid solution. How many liters of each of these solutions should be mixed together to make 24L of 30% solution? Enter two numbers separated by a comma
March 1, 2012

AJ
How do the three subsytems :law enforcement, cout, and corrections interact with each other? sorry for misspelling
February 23, 2012

AJ
How do the three susytems law enforcemnt, cout, and corrections interact with each other?
February 23, 2012

math
A board is divided into rectangles each 2/15 in long What is the length of one rectangle written as a decimal
January 19, 2012

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