Wednesday

May 6, 2015

May 6, 2015

Total # Posts: 3,123

**science**

When you hit a nail into a board using a hammer, the head of the nail gets warm. In terms of kietic and thermal energy, describe why you think this happens.
*January 23, 2013*

**calculus**

Let f(x)=(2+x)2−4x. Note that f(x) is undefined at x=0. However, in this case, we can find a continuous function g(x) defined at x=0 that agrees with f(x) near x=0. Find the function g(x) that is equal to f(x) when x≠0 such that g(0)=limx→0f(x).
*January 19, 2013*

**calculus**

Let f(x)=x2+x−6x−2. Note that f(x) is undefined at x=2. However, in this case, we can find a continuous function g(x) defined at x=2 that agrees with f(x) near x=2. Find the function g(x) that is equal to f(x) when x≠2 such that g(2)=limx→2f(x).
*January 19, 2013*

**math**

A pattern for curtains calls for 2/3 of a yard of material. You want to shorten the curtains to2/3 of the height of the pattern. How much fabric is needed?
*January 18, 2013*

**Calculus**

Use a trig identity to combine two functions into one so you can solve for x. (The solution should be valid for any value of t). 3cos(t) + 3*sqrt(3)*sin(t)=6cos(t-x) I know that 6 cos(t-x) can be 6(cos(t)cosx(x)+sin(t)sin(x)) I dont know where to go from there though.
*January 15, 2013*

**Calculus**

In these complex exponential problems, solve for x: 1)e^(i*pi) + 2e^(i*pi/4)=? 2)3+3=3i*sqrt(3)=xe^(i*pi/3) MY attempt: I'm not really sure of what they are asking. For the 1st one I used the e^ix=cos(x)+i*sin(x) and got -1+sqrt(2) +sqrt(2)i 2) I solved for x and fot (3+3i...
*January 15, 2013*

**chemistry**

okay thank you very much :)
*January 14, 2013*

**chemistry**

thanks for the help i really appreciate it :D
*January 14, 2013*

**chemistry**

i know how to grapgh it and all i am only stuck with how to find the intial molar concentration. i believe you're telling me the step to finding the ka value. sorry i am a little confused with this
*January 14, 2013*

**chemistry**

the data is Vol. of NaOH added 0 1 2 3 4 5 10 15 20 21 22 23 24 25 26 27 28 29 30 35 40 45 50 pH 2.92 3.47 3.79 3.98 4.13 4.25 4.67 5.03 5.57 5.72 5.91 6.23 8.78 11.29 11.59 11.75 11.87 11.96 12.22 12.36 12.46 12.52 this is the data and this was given
*January 14, 2013*

**chemistry**

so this is the question: you will be given a sample of nictinic acid with an unknown concentration, and it will be titrated with 0.100M NaOH. instead of measuring the volume of the basic solution required to reach the endpoint, however, you will measure the pH. Then you will ...
*January 14, 2013*

**chemistry **

the chemical equation of nicotinic acid is C5H4NCOOH + NaOH --> C5H4NCOONa + H2O i need to calculate the intial molar concentration of this acid, based on the ratio in which the acid and base react. Please help i cant figure it out,
*January 14, 2013*

**Physics**

Stand two plane mirrors on their edges and parallel to one another. Place a coin between them near one end. How many images do you see? Draw a ray diagram to explain the formation of the images.
*January 13, 2013*

**Physics**

Stand two plane mirrors on their edges and parallel to one another. Place a coin between them near one end. How many images do you see? Draw a ray diagram to explain the formation of the images.
*January 13, 2013*

**Chemistry**

What is the mass of water that can be heated from 39 C to 80 C by the combustion of 150 g of methane. CH4 + 2O2 => CO2 + 2H2O Delta H= -890kJ
*January 11, 2013*

**Chemistry**

a)vii b)i
*January 11, 2013*

**algebra 2**

help please!! state the possible rational zeros for each function. then find all zeros. y=x^3-13x^2-x+13 show all the step please .thanks
*January 9, 2013*

**English**

Which sentance shows the verb in correct agreement with the subject? I have narrowed it down to these two sentences: A. Peggy or Phyllis drive me to Florida every winter. B. Not only the muffler but also the spark plugs need to be replaced. I want to go with A, but B also ...
*January 9, 2013*

**Science**

What things in the environment where I live in Hollister, CA determine the local ecosystem?
*January 8, 2013*

**algebra**

Is this mrs.. Berry
*January 8, 2013*

**grammar**

Which of the following contains a correct, standard use of a comma
*January 5, 2013*

**calculus**

Find the midpoint of the line segment joining the points P1 and P2 P1=(-1,5); P2=(2,0) m=(x,y)=? type an ordered pair Please show work
*January 1, 2013*

**calculus**

Find the distance d(P1,P2)between the points P1 and P2. P1=(-5,2) P2=(2,1) d(P1,P2)=? *all the 1's and 2's are to be lower down.* Please show work
*January 1, 2013*

**math**

the width of a rectangular garden is 2 m less than its length. Determine the dimensions of the garden if the area is 36 m2. thanks!
*December 30, 2012*

**CHEMISTRY**

(c) What is the value of the degree of polymerization n of isotactic PB with a molecular weight of 3.091×105 g/mol?
*December 29, 2012*

**pre algebra**

a typist works from 10am to 6pm making $120 for the day. after typing from the end of page 8 to the end of page 50, find the number of pages per hour. find the rate of pay in dollars per page
*December 28, 2012*

**math**

Solve 4a2 + 25 = –20a by factoring. Verify your solution Solve and verify the following equation: 13x2 + 35x + 21 = –12x2 – 25x – 15
*December 28, 2012*

**math**

One bag contains 6 red chips and 5 yellow chips. Another bag contains 6 red chips and 4 yellow chips. A chip is drawn from each bag. What is the probability that both chips are yellow?
*December 26, 2012*

**ASAP help CHEMISTRY**

I am completely lost on partial pressure. Please work it out for me so i can see the step by step. THANKS!
*December 19, 2012*

**ASAP help CHEMISTRY**

A cyclopropane-oxygen mixture is used as an anesthetic. If the partial pressure of cyclopropane in the mixture is 334 mmHg and the partial pressure of the oxygen is 1.02 atm, what is the total pressure of the mixture in torr?
*December 19, 2012*

**algebra 2**

2x^2-5x-3 show all the step please thanks
*December 19, 2012*

**algebra 2**

find the solution ,show all the step please y=x^3+125
*December 19, 2012*

**chemistry**

Chemical analysis of a silicon crystal reveals gallium at a level of 3.091×10−6 atomic percent. Assuming that the concentration of thermally excited charge carriers from the Si matrix is negligible, what is the density of free charge carriers (free carriers/cm3) in ...
*December 14, 2012*

**CHEMISTRY HELP PLEASE**

so am i not using V=nRT/P
*December 14, 2012*

**CHEMISTRY HELP PLEASE**

2NaN3(s)==>2Na(s) + 3N2(g) How many liters of N2 are produced at STP if the air bag contains 114g of NaN3 ?
*December 14, 2012*

**algebra 2**

how can i solve this help please show the step 3square rood of 64x^4
*December 13, 2012*

**algebra 2**

what is the square root of 196x^12
*December 12, 2012*

**algebra 2**

take the square root problem square root 196x^12 show the step please thanks
*December 12, 2012*

**algebra 2**

take the square root of problem square root 64x^6
*December 12, 2012*

**algebra 2**

find the zeros of quadratic ( 8v+7)(v-2)=0 show the step please
*December 12, 2012*

**algebra 2**

take the square root of problem square root 64^6 please show all work
*December 12, 2012*

**algebra 2**

find the zeros of quadratic ( 8v+7)(v-2)=0 show the step please
*December 12, 2012*

**Introduction to High School**

D. A desk stocked with supplies
*December 11, 2012*

**Introduction to High School**

All of the following are characteristics of an effective study environment EXCEPT: A. a relaxing area such as your bedroom B. comfortable and balanced temperature C. ample amounts of natural light D. a deck stocked with supplies
*December 11, 2012*

**social studies**

IN THE ELECTION OF 1912, Teddy Roosevelt's Bull Moose Party platform was built around what he called the a.fair deal b.square deal I think it's a fair deal but not sure
*December 10, 2012*

**statistics**

Compare the 95%(6.214,7.686) and 99% 95.944,7.956)confidence intervals for the hours of sleep a student gets. Explain the difference between these intervals and why this difference occurs.
*December 8, 2012*

**statistics**

Compare the 95%(6.214,7.686) and 99% 95.944,7.956)confidence intervals for the hours of sleep a student gets. Explain the difference between these intervals and why this difference occurs.
*December 8, 2012*

**algebra 2**

check my answer please find the number of zeros(x-intercepts) y=3k^3-6k^2-45k=k(3k+9)(k-5)= k(3k^2-15k+9k-45)=k(3k^2-6k-45) or should i do it 3k(k-5) (k+3)=3k(k^2+3k-5k-15)=3k(k^2-2k-15) which on is the right one please let me know.thanks
*December 7, 2012*

**Geometry**

The lengths of the sides of a triangle are 3,5, and 7 inches. How many inches long is the shortest side of a similar triangle that has a perimeter of 75 inches? F.10 G.12 H.14 H.15 k.22
*December 7, 2012*

**algebra 2**

-7.8
*December 7, 2012*

**algebra 2**

find the number of zeros(x-intercept) y=a^2+a-56 show the step please.
*December 7, 2012*

**algebra 2**

i have big number -45,99,127,358
*December 7, 2012*

**algebra 2**

given the zeros,write a polynomial equation in factored form.zeros: -45,99,127,358 show all the step please.
*December 7, 2012*

**algebra 2**

given the zeros, write a polynomial equation in factored form.zero -5,9,12 show all the step please
*December 7, 2012*

**chemistry**

You wish to remove nitrogen from the near-surface region of a plate of cobalt which is 1.0 cm thick. The plate is placed in a furnace at 417∘ C where an atmosphere of H2 and NH3 reacts with the nitrogen in the cobalt and fixes the surface concentration to 111 ppm (parts ...
*December 7, 2012*

**chemistry**

You wish to remove nitrogen from the near-surface region of a plate of cobalt which is 1.0 cm thick. The plate is placed in a furnace at 417∘ C where an atmosphere of H2 and NH3 reacts with the nitrogen in the cobalt and fixes the surface concentration to 111 ppm (parts ...
*December 7, 2012*

**chemistry**

You wish to remove nitrogen from the near-surface region of a plate of cobalt which is 1.0 cm thick. The plate is placed in a furnace at 417∘ C where an atmosphere of H2 and NH3 reacts with the nitrogen in the cobalt and fixes the surface concentration to 111 ppm (parts ...
*December 7, 2012*

**chemistry**

You wish to remove nitrogen from the near-surface region of a plate of cobalt which is 1.0 cm thick. The plate is placed in a furnace at 417∘ C where an atmosphere of H2 and NH3 reacts with the nitrogen in the cobalt and fixes the surface concentration to 111 ppm (parts ...
*December 7, 2012*

**chemistry**

You wish to remove nitrogen from the near-surface region of a plate of cobalt which is 1.0 cm thick. The plate is placed in a furnace at 417∘ C where an atmosphere of H2 and NH3 reacts with the nitrogen in the cobalt and fixes the surface concentration to 111 ppm (parts ...
*December 7, 2012*

**chemistry**

An undesirable consequence of welding steel by acetylene torch is the rise in hydrogen concentration in the metal. That hydrogen contamination embrittles the steel. The metal is typically subjected to a vacuum heat treatment to restore ductility. A steel part is placed in a ...
*December 7, 2012*

**chemistry**

"Carburization" of pure iron (Fe) is carried out at 950∘ C. It is desirable to achieve a carbon content of 0.9% at a depth of 0.1 mm below the surface. A constant supply of carbon at the surface maintains a surface concentration of 1.2%. Assuming the ...
*December 7, 2012*

**math**

make a 5 by 5 tile uisng 5 different colors. None can be in the same row nor be diagional.
*December 7, 2012*

**Chemistry**

Using Dimensional Analysis One mole of sillicon has a mass of 28.1 g, and one mole of oxygen has a mass of 16.0 . What is the mass of one mole of sillicon dioxide.
*December 6, 2012*

**PHYSICS - PLEASE HELP**

total momentum = m1(v1)+m2(v2)+m3(v3) total momentum = [(5)8]+[(-4)15]+[(2)3] total momentum = (40)+(-60)+(6) total momentum = (-20)+(6) = -14 Answer: A
*December 6, 2012*

**7th grade math Ms. Sue please**

me too. it's awful
*December 5, 2012*

**5th grade math**

Jason ate lunch at Virginia’s Diner. If his meal cost him $11.00, and he wants to leave Virginia a 15% tip, how much money should Jason leave for the total bill? A. $11.50 B. $12.00 C. $12.36 D. $12.50 E. $12.65 how do you do this?
*December 4, 2012*

**Chemistry?HELP**

Is carbon graphite or a diamond harder to break or scratch and why. You must use an explanation of molecular geometry, intermolecular and intramolecular forces to answer this question. I'm confused...
*December 4, 2012*

**Chemistry**

The fictitious compound, arrhenium fluoride ( ), reacts with itself to form a dimer with the formula Ah2F2 . The reaction is second order in AhF. The value of the rate constant is 8.591x10-3 M-1s-1. What is the initial rate of reaction in a reactor filled with AhF to a ...
*December 4, 2012*

**CHM**

Predict whether the following bonds are ionic, covalent, or polar covalent based on the bonding atoms electronegativities: N2 The Al-O bond in Al2O3 MgO CuS
*December 3, 2012*

**MATH**

From HOME TO THE FAIR IT'S 70 MILES, I have driven about 30 miles at 40 miles per hour. how many hours would it take me to finish the remaining miles?
*December 3, 2012*

**accounting**

On September 1, 2013, Jacob Furniture Mart enters into a tentative agreement to sell the assets of its office equipment division. This division qualifies as a component of the entity according to GAAP regarding discontinued operations. The division's contribution to Jacob...
*December 3, 2012*

**chemistry**

Urbium (Ur) is an upscale element found in big cities. Its oxide (UrO2) is not very stable and decomposes readily at temperatures exceeding 66∘ C. The figure below shows how the rate of reaction varies with the concentration of UrO2 at 75∘ C. The rate r is in units...
*December 1, 2012*

**chemistry**

Normal glucose levels in the blood are from 70 to 110 mg glucose per 100 mL of blood. I the level falls too low, there can be brain damage. If a person has a glucose level of 108 mg/100 mL, what is the total mass of glucose in grams in 5.10L of blood?
*November 29, 2012*

**algebra 1**

Two vans leave town at the same time going in opposite directions. one travels at 60 miles/hr. the second travels 30 miles/hr. in how many hours will they be 180 miles apart?
*November 28, 2012*

**chemistry**

15.00 ml of NaOH is obtained in an Erlenmeyer flask. Before titrating with .2500 M HCl, the initial volume of acid in a buret is read as 2.08 ml. At the endpoint the final volume of acid in the buret is 25.20 ml. What was the concentration of NaOH?
*November 28, 2012*

**physics**

thank you very much!
*November 27, 2012*

**physics**

ah thanks, it's 10^3 kg/m^3
*November 27, 2012*

**physics**

A box with a volume V = 0.03 m^3 lies at the bottom of a lake whose water has a density of 103 kg/m^3. (a) How much force is required to lift the box, if the mass of the box is 100 kg? (b) How much force is required to lift the box, if the mass of the box is 70 kg?
*November 27, 2012*

**maths**

Let A, B and C be the sets such that A ∪ B = A ∪ C and A ∩ B = A ∩ C. Show that B = C.
*November 27, 2012*

**Algebra**

Let L= 3x and B = 2x. P = 2L + 2B 73= 2(3x)+2(2x) 73= 6x+4x 73= 10x or x = 73/10 x = 7.3 cm Now, L = 3x= 3(7.3)=21.9 cm and B = 2x= 2(7.3)=14.6 cm
*November 27, 2012*

**math**

If the key to Graceland costs $750 today and appreciates in value by 15% in one year, what will it be worth one year from today?
*November 26, 2012*

**math**

find first 4 terms of following sequence: a1=-6 abd an=2an-1+3 for n >2
*November 26, 2012*

**math**

whats the present value of 850.00 made in 10 years with a discount rate of 12%
*November 24, 2012*

**math**

so am i then 150 (1.07)^7%
*November 24, 2012*

**math**

ok now the same 8 years at 8% with a deposit of 150.00 can you please show me the calculation
*November 24, 2012*

**square roots**

Describe the Number systems used in mathematics with the use of subsets of the real number system.
*November 20, 2012*

**math**

if my input numbers are 1,2,3,4,5,6 and my output numbers are 8, 14, ?, 24,28,?...I cannot figure out the rule and the numbers where the question marks should be.
*November 14, 2012*

**math**

I am trying to figure out an input/output problem: Input Output 1 8 2 14 3 - - 24 - 28 6 -
*November 14, 2012*

**pre-algebra**

write 16/19 in decimal notation
*November 13, 2012*

**Math**

Ricky wrote the following to show that his sister's age is 6 yrs. less than 3 times his age. Explain what he did wrong. Give the correct expression Let a stand for my age My sister's age a/3-6
*November 12, 2012*

**Stattistics**

In one elementary school, 200 students are tested on the subject of Math and English. The table below shows the mean and standard deviation for each subject. Mean SD Math 67 9.58 English 78 12.45 One student’s Math score was 70 and the same individual’s English score...
*November 11, 2012*

**chemistry**

balanced equation for potassium nitrate(s)--->potassium nitrate(s)+oxygen(g)
*November 8, 2012*

**Chemistry**

If 0.10 mg Fe is diluted in a 50 mL flask, what is the concentration of the resulting solution? What volume of the resulting solution is needed to prepare 25.0 mL of a dilute sample solution with a concentration of 0.30 ppm Fe?
*November 8, 2012*

**College Math**

i'm having trouble calculating this. can someone help please? A $7,000, 4%, 120-day note, dated March 20, is discounted on July 15. Assuming a 3% discount rate, the bank discount is: a) $1.74 b) $1.77 c) $7.11 d) $17.68 e) None of these .
*November 8, 2012*

**Valencia**

2.0L of a 2.0M HCl solution is added to water so that the final volume is 6.0L
*November 6, 2012*

**Science- chemistry**

After extraction with bicarbonate in which layer is the benzoic acid?
*November 6, 2012*

**chemistry**

what mass of silver bromide will form when 25.00 mL of a 0.0675 M MgBr2 solution is combined with mL of 0.100 M AgNO3?
*October 30, 2012*

**MATH**

FAITH HAS A TRIANGULAR SANDWICH AND ONE SIDE THAT IS 4IN LONG AND ANOTHER SIDE IS 3 IN WHAT IS THE RANGE OF THE THIRD SIDE
*October 30, 2012*

**management science**

Kim Davis has decided to purchase a cellular phone, but she is unsure about which rate plan to select. The "regular" plan charges a fixed fee of $55 per month for 1,000 minutes of airtime plus $0.33 per minute for any time over 1,000 minutes. The "executive"...
*October 27, 2012*

**chemisty**

a 10.00ml diluted chloride sample required 44.89 ml of 0.01982 m abno3 to reach the fajans end point. how many moles of cl ion were present in the sample
*October 25, 2012*