Tuesday

October 21, 2014

October 21, 2014

Total # Posts: 290

**Pyschological Statistics**

In a distribution with a standard deviation of eight, an individual score of 42 corresponds to a Z score of -0.5. What is the mean of this distribution?
*October 8, 2014*

**Math**

Billing office is trying to figure out the amount of 0.75 hour overtime for a worker who is paid $32.48 for A regular hourly rate. The overtime rate is 1.5 of his regular hourly rate. How much is 0.75 of an hour at the overtime rate for this worker
*July 14, 2014*

**Algebra II**

When asked to solve the rational equation 11/2x^2+x-15=5/2x-5-x/x+3 a student multiplied both sides of the equation by the expression (2x2+x−15)(2x−5)(x+3). Was this the best thing for the student to do? If not, what should the student have done?
*July 13, 2014*

**physics**

A particle (m=3*10^-6 g, q=5*10^-6 C) moves in a uniform magnetic field given by (60j) mT. At t=0 the velocity of the particle is equal to (30j - 40k)m/s. The subsequent path of the particle is? I know that the answer is: helical with a 40-cm radius. But i dont know the ...
*July 1, 2014*

**Algebra II**

Find the difference quotient for the following Rational Function f(x)=5/x using the four steps outlined below. a. find f(x+h) b. find f(x) c. substitute f(x+h) and f(x) into the difference quotient formula. d. simplify
*June 23, 2014*

**Algebra II**

In front of the letter n there is actually the pie sign
*June 15, 2014*

**Algebra II**

I wrote out the word pie in place of the actual symbol. Consider (pie n+pie n-1)(pie n-pie n-1)= 1 for n greater than or equal to 1. a) Provide two numerical examples illustrating its validity. b) Show the statement is true in general. c) What is the difference ...
*June 15, 2014*

**Algebra II**

Find the error in each of the following and provide an explanation of the mistake made. Thanks for the help. a) (3x/1/x-5)^1 =1/3x/x-1/5 b) (3x/1/x-5)^1 =-3x/5-1/x c) (3x-4y)^2 = 9x^2 + 16y^2 d) x^2-3/4+x^2=-3/4
*June 15, 2014*

**Algebra II**

The measure of the largest angle of a triangle is 90 more than the measure of the smallest angle, and the measure of the remaining angle is 30 more than the measure of the smallest angle. Find the measure of each angle. Show your work in obtaining your answer.
*June 9, 2014*

**algebra**

Write the numeral as a Roman numeral. 503,303 A. MMCCCIII B. MMMCCCIII C. MMCCCXIII D. MMCCIII
*March 19, 2014*

**history**

India's history has often been associated with the life and thought of Mohandas Gandhi. Gandhi insisted that all his followers remain nonviolent. For him, ahimsa (nonviolence) was essential. What accounted for the success of ahimsa? Can you think of any American parallels ...
*January 21, 2014*

**computer science**

Best practices for securing local networks?
*November 18, 2013*

**science**

a car eneters a freeway with a speed of 6.7 m\s and accelerates uniformly for 3.0 I 3.8 min . how fas the car moving after this time?
*September 22, 2013*

**English**

What comes to mind when you think of needing more time? Some examples might be studying, family, exercise, relaxation, a hobby, or building your business
*April 17, 2013*

**college english**

2 paragraph essay..What comes to mind when you think of needing more time? Some examples might be studying, family, exercise, relaxation, a hobby, or building your business
*April 14, 2013*

**algebra**

An investor invested a total of $2200 in two mutual funds. One earned 5% profit while the other earned a 3% profit. If the investor's total profit was $86, how much was invested in each mutual fund?
*April 5, 2013*

**english**

Trust in the Lord with all of your heart.Do not depend on your own understading.
*March 1, 2013*

**Early childhood**

Foundations of development
*February 13, 2013*

**Physics**

A trolley of mass 2kg accerates from rest across a rough surface at 2,5m.s.It experiences a frictional force of 3N.Calculate the velocity of trolley after 4s and the distance travelled by the trolley in 4s
*January 23, 2013*

**alegbra 1**

X+12+x<44
*October 31, 2012*

**Math**

use compatible number to estimate problem: 1,212 + 347 537 + 3,244 329 + 64
*October 2, 2012*

**Comunication Skills**

You speakers of Castilian Spanish and Cantonese Chinese may be especially vulnerable to environmental influences in the mainstream classroom because of their: A. oral traditions b. linguistic environments c. cultural histor d. dialectal dominance
*September 7, 2012*

**MATH**

IF I SOLD 592 TICKETS EACH FOR $6.00 EACH HOW MUCH MONEY WILL I MAKE
*September 5, 2012*

**sci/275**

on the emission calculator what was your highest contributor
*August 21, 2012*

**health**

lol me 25th
*August 11, 2012*

**Chemistry **

5g of calcium carbonate reacted with 0.5mols of sulfuric acid, what mass of carbon dioxide is produced?
*June 3, 2012*

**math**

If a serving size is 1/6 and at the end of the night the restaurant has 5 3/8 left how many servings are left?
*May 4, 2012*

**physics**

an electron has a kinetic energy that is 1.8 times its rest energy. What is its speed, expressed as a fraction of the speed of light?
*April 16, 2012*

**algebra**

Suppose you have a can of paint that will cover 400 ft squared. A. find the radius of the largest circle you can paint. Round to the nearest tenth of a foot.( hint use the formula A=3.14 times radius squared B. Suppose you have two cans of paint, which will cover a total of ...
*April 12, 2012*

**Math**

Moniques credit card charges interest of 20.85% per annum on unpaid balances on her march 12 statement. she had a balance of $739.65 due by the due date, she made the minimum payment (5% or 10.00, Whichever is greater.) On march 16. She made a purchase of $179.39 a)If she ...
*April 10, 2012*

**Geometry**

Which of the following can be used to describe the triangle with the vertices listed below? F(-1, 2), G(-10, 2), H(-12, -11) I. acute II. obtuse III. right IV. scalene V. isosceles VI. equilateral --------Please help!!! Explain.
*March 26, 2012*

**Geometry**

two perpendicular lines with the equations y=1/3x+9 and y=mx-3 contain the consecutive sides of a rectangle. What is the value of mx in the 2nd linear question.
*March 25, 2012*

**geometry**

During the half-time show of a football game, a trumpet player and a tuba player start at the same position on the field. The trumpet player then marches 74.8 ft directly toward the goal line, and the tuba player marches directly toward the sideline. At the end of their march...
*March 25, 2012*

**Geometry**

A right triangle with G and F as the two base angles and E as the top angle. Side EF is Y, side FG is x, while side EG is 2x. If Y = 15, what is the value of x? ----Please help, and explain.
*March 25, 2012*

**Algebra**

Two perpendicular lines with the equations y=1/3x+9 and y=mx-3 contain consecutive sides of a rectangle. What is the value of m in the second equation?
*March 25, 2012*

**Geometry**

Which of the following can be used to describe the triangle with the vertices listed below? F(-1, 1), G(-8, 1), H(-9, -10) I. acute II. obtuse III. right IV. scalene V. isosceles VI. equilateral -----Please show me how you got the answer
*March 25, 2012*

**Pre-cal**

Does the equation x^2+x-12/x+2 have holes?
*March 21, 2012*

**bio**

The cell membrane is a highly selective barrier that controls the movement of substances in and out of the cell. In fact, polar molecules are unable to go across unless A. they are enclosed in water-filled vesicles. B. they pass through channels in the cell membrane. C. they ...
*March 21, 2012*

**biology**

Food that is consumed often enters the body in the form of large organic molecules, such as proteins and starches. Prior to entering cells, however, these large molecules must be broken down into smaller molecules. For example, proteins are digested into _______ prior to ...
*March 21, 2012*

**biology**

Organisms must be able to adapt to a changing external and internal environment. An organism's ability to maintain a stable internal environment is known as homeostasis. How does a cell's membrane help an organism maintain homeostasis? A. Cell membranes use a large ...
*March 21, 2012*

**Geometry **

Find the equation of the line passing through the given points (1,5) (2,7) please show work
*February 28, 2012*

**chemistry**

how many chloride (CL negative two) ions are needed to balance a positive charge of Barium positive two?
*February 21, 2012*

**physics**

When a mass of 28 g is attached to a certain spring, it makes 19 complete vibrations in 3.9 s. What is the spring constant of the spring? Answer in units of N/m
*February 16, 2012*

**Physics**

A mass of .24 kg is attached to a spring and is set into vibration with a period of .30 s. What is the spring constant of the spring? Answer in units of N/m
*February 16, 2012*

**Geometry **

Angle A and Angle B are complementary andgles and the m Angle A = 58 degrees, what is he measure of the supplement of Angle B. This is what I did Angle A and Angle B = 90 degrees, mAngle A = 58 degrees 90 - 58 = 32 degrees 180 - 32 = 148 M angle B supplement = 148 degrees Am I...
*February 6, 2012*

**Geometry**

Z is between I and P. Solve for x and find IP. IZ= 3x+5 ZP= 4x+13 IP= 15x-22
*January 29, 2012*

**Communication**

Imagine you are the office manager for a medical practice and have recently attended a conference where you learned about active listening and its benefits. You want to share the information with your practice’s staff.
*December 26, 2011*

**MATH**

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 174 and a variance of 9. The material is considered defective if the breaking strength is less than 168 pounds. What is the probability that a single, randomly selected piece ...
*December 11, 2011*

**Math**

a mountain with a base 5977 feet below sea level rises 17365 feet. what is the elevation of its peak
*December 10, 2011*

**Chemistry**

50.0 ml sample of ethylene has a mass of 55.505g. Find the density of ethylene.
*December 7, 2011*

**chemistry**

calculate the amunt of heat required to completely boil 250g of water starting from room temp 22 degrees C
*December 6, 2011*

**chemistry**

why does rubbing alcohol feel cold when its applied to the skin?
*December 6, 2011*

**chemistry**

calculate the heat liberated when 118g of water at 0 degrees C is frozen?
*December 6, 2011*

**chemistry**

Potash is composed mainly of potassium carbonate, K2CO3. If 1.000g of potash reacts with sulfuric acid to produce 145 mL of carbon dioxide gas at STP, what is the percentage of potassium carbonate in the marble sample? K2CO3 + H2SO4 ==> K2SO4 + H2O + CO2
*November 28, 2011*

**chemistry**

A wooden boat discovered just south of the Great Pyramid in Egypt had a carbon - 14 content of approximately 50% of that found in living organisms. How old is the boat?
*November 26, 2011*

**chemistry**

A radioactive sample contains 2.45g of an isotope wiht a half life of 3.8 days. How much of the isotope in grams remains after 11.4 days? please explain
*November 26, 2011*

**chemistry**

Silver is electroplated at the cathode of an electrolysis cell by the half reaction Ag+(aq) + e- --> Ag(s) How many moles of electrons are required to electroplate 5.8g of Ag?
*November 25, 2011*

**chemistry**

O# of Cr(OH)4- How did you get +3
*November 25, 2011*

**chemistry**

Balance the redox reactin in basic. ClO- + Cr(OH)4- --> CrO42- + Cl- H2O + ClO- --> Cl- + 2OH ClO- has a +1 O# and Cl- has a -1 O# how do I balance that. And is what Ive done so far correct? Cr(OH)4- --> CrO42- Im confused on how to balance the oxygen and hydrogens ...
*November 25, 2011*

**chemistry**

please help this equation is driving my crazy. balance the following redox reaction in basic solution. H2O2 + ClO2 --> ClO-2 + O2
*November 23, 2011*

**chemistry**

Balancing Redox Reaction in Basic Solution CN- + MnO-4 --> CNO- + MnO2 H2O + CN- --> CNO- + 2H +2e 3e + 4H + MnO4- --> MnO2 + 2H2O My confusion is with adding the OH- please explain
*November 22, 2011*

**chemistry**

Oxidation CN- C=2+ N=3- Can you explain how C is 2+
*November 22, 2011*

**chemistry**

Am I headed in the right direction. Sn + MnO4- --> Sn2+ + Mn2+ Sn --> Sn2+ + 2e- 5e + 8H + MnO4- --> Mn2+ + 4H2O If Im right what is the whole number that Im multiplying by
*November 20, 2011*

**chemistry**

I can see that now thank you very much
*November 20, 2011*

**chemistry**

Please explain this to me 2I- --> I2 + 2e Cr2O72- ==> Cr3+ 6e + 14H + Cr2O72- ==> 2Cr3+ + 7H20 I dont understand how the left side gets 6 electrons.
*November 20, 2011*

**chemistry**

Balance the following redox reaction occurring in acidic solution Cu(s) + NO3-(aq)--> Cu2+(aq) +NO2(g) This is what I have done so far Cu-->Cu2+ + 2e- 2H + NO-3 --> NO2 + H2O Need help please
*November 20, 2011*

**chemistry**

Balance the following redox reaction occurring in acidic solution. H+ + Cr --> H2 + Cr3+ H+ --> H2 do I add H+ to this side since H2 = 0? Also what about electrons. Cr -> Cr3+ + 3e- Hope I make sense
*November 18, 2011*

**chemistry**

Fe2+ + MnO-4 --> Fe3+ + Mn2+ Fe2+ = +2 Mn = +7 O-4 = 4(-2) = -8 Fe3+ = 3+ Mn2+ = 2+ ok so next I gave 8H to MnO-4 and 4 H20 to Mn2+ Next I starting adding my electrons. 1e- to Fe3+. I understand that. This is where Im lost according to my book I give 5e- to the reactant ...
*November 18, 2011*

**chemistry**

How does the N in NO2 have a oxidation state of 4+ please explain
*November 18, 2011*

**chemistry**

use oxidation states to identify the element that is being oxidized and the element that is being reduced in the redox reaction Sn + 4HNO3 ---> SnO2 + 4NO2 + 2H2O I see that SN is oxidized 0 --> 4+ and book says N is reduced +5 --> +4 I dont see that. Please help
*November 18, 2011*

**chemistry**

A rolaids tablet contains calcium carbonate which neutralizes stomach acid. If rolaids tablet neutralizes 42.15 mL of 0.320M hydrochloric acid, how many milligrams of calcium carbonate are in a Rolaids tablet CaCO3 + 2 HCl ------> CaCl2 + H2O + CO2 Pls show steps
*November 15, 2011*

**chemistry**

ok DrBob the answer i got was 2.7 x10-5 am i correct
*November 12, 2011*

**chemistry**

What is the concentration of the Mg2 ion in solution when [CO3-2] = 0.25M given that the Ksp= 6.82 x 10-6 for the following reaction MgCO3-------->Mg +. CO32- Chemistry - DrBob222, Friday, November 11, 2011 at 5:34pm Ksp = (Mg^2+)(CO3^2-) Substitute 0.25M for CO3^2- and ...
*November 12, 2011*

**Chemistry**

Name 3 buffers that exist in the human body? Include the conjugate and acid base pairs
*November 11, 2011*

**Chemistry**

For the reaction 2 N2O <===>O2 + 2 N2 what happens to the equilibrium position if the pressure is increased
*November 11, 2011*

**Chemistry**

Second thought I just don't understand what to do. pH= pKa + log [NH3]/[NH4NO3] pH= -l log ? + log (0.005/?) pH= ? pH= ?
*November 11, 2011*

**Chemistry**

Don't think I know how to calculate the M of NH4NO3
*November 11, 2011*

**Chemistry**

So is it a problem if the conch of NH4NO3 was not given to me. Or do I just assume it's the same as the NH3
*November 11, 2011*

**Chemistry**

Calculate the pH buffer made by combing 50.0 mL of 1.00M ammonia and 50.0mL of ammonium nitrate. Can I use the same formula? If so do I do anything with the mL
*November 11, 2011*

**chemistry**

DrBob I want to thank you SOOOOO much for all the help you give. I had never heard of the H H equation. And I also appreciate you patience
*November 11, 2011*

**chemistry**

This what I did log(1.76 x 10-5) +log(0.150/0.200) = 4.879
*November 11, 2011*

**chemistry**

No I'm sorry I just used this as the example of the H H equation
*November 11, 2011*

**chemistry**

pH = pKa + log ([A-]/[HA]) pH = pKa + log ([C2H3O2-] / [HC2H3O2]) pH = -log (1.8 x 10-5) + log (0.50 M / 0.20 M) pH = -log (1.8 x 10-5) + log (2.5) pH = 4.7 + 0.40 pH = 5.1 I used this example And I still got it wrong it should have been 4.75 + 0.12 = 4.87 or do I use just 4.7...
*November 11, 2011*

**chemistry**

Ok DrBob I think I got it after all the plugging in my final answer is 5.45 I hope
*November 11, 2011*

**chemistry**

calculate the pH of a buffer solution containing 0.200M acetic acid, HC2H3O2, plus 0.150M sodium acetate. The dissociation constant for HC2H3O2 is 1.76 x 10-5 I dont think our instructor gave enough notes on these things Im kind of winging it from the book. Could you please ...
*November 11, 2011*

**chemistry**

I'm stuck Ka=1.84 x 10-4= x x/ 0.125 (1.84 x 10-4)[0.125] 2.3 x 10-5= x = [H30] lost which way do I go
*November 11, 2011*

**chemistry**

DrBob is the HCOOH---->H^++HCOO^ the HCHO2
*November 11, 2011*

**chemistry**

calculate the hydronium ion concentration in 0.125M formic acid, HCHO2 Ka= 1.8 x 10-4 can you show me the steps pls
*November 11, 2011*

**Chemistry**

What happens to the equilibrium constant when a catalyst is added to the reaction mixture. A. Increase B. Decrease C. Does not change D. Varies E. None of the above I chose c
*November 11, 2011*

**Chemistry**

What is the concentration of the Mg2 ion in solution when [CO3-2] = 0.25M given that the Ksp= 6.82 x 10-6 for the following reaction MgCO3-------->Mg +. CO32-
*November 11, 2011*

**Chemistry**

For the reaction Ag2S <====> 2Ag + S2 what happens to the equilibrium position if aqueous ammonium sulfide is added A. Shift left B. Shifts right C. Does nothing D. Doubles E. Halves
*November 11, 2011*

**Chemistry**

Identify the equation for which Keq= [Cu+]2[S2-]
*November 11, 2011*

**chemistry**

I got - log (0.0045) = 4.75
*November 11, 2011*

**chemistry**

what is the ph of a solution that has [H] = 0.0045 can you show steps pls
*November 11, 2011*

**chemistry**

I need help calculating [H3O] from pH and the pOH scale using my calculator. I have a TI-30XIIS
*November 11, 2011*

**chemistry**

what is the pH of a solution that has a H+ concentration equal to 1.76 x 10-5M? I got 4.75 is this correct
*November 11, 2011*

**chemistry**

what is the concentration of the hydroxide ion in an acidic solution?
*November 11, 2011*

**chemistry**

i think this is because water always has some ions in it. am i right
*November 10, 2011*

**chemistry**

If pure water cant conduct electricity why do we have to be careful with electrical appliances near water.
*November 10, 2011*

**chemistry**

a 25.0ml dsmplr og 0.105M HCI was titrated with 31.5ml of NaOH. What is the concentration of the NaOH I got 0.0834M am I correct HCI + NaOH -----> H20 + NaCl 25.0ml HCI x 1L/1000mlx0.105 mol HCI/1L HCI X 1 mol NaOH/ I mol HCI = 0.0834M
*November 10, 2011*