Friday

February 24, 2017
Total # Posts: 790

**chemistry**

The escape velocity from earth is 2.5 x10^4 miles per hour. What is this speed in m/s? (1 mile 1609 m)

*April 14, 2013*

**math**

Simplify this expression by using the properties of exponents.You may leave your answer as a number to a power. (2c)^5(2c^9)^6=

*April 13, 2013*

**finance**

You have a fairly large portfolio of U.S. stocks and bonds. You meet a financial planner at a social gathering who suggests that you diversify your portfolio by investing in emerging market stocks. Discuss whether the correlation results in Exhibit 3.10 support this suggestion

*April 11, 2013*

**Pre-Algebra**

Find 3 consecutive positive integers such that the product of the first and third, minus the second, is 1 more than 5 times the third.

*April 7, 2013*

**Psychology**

One way to measure the validity of test would be to:

*April 5, 2013*

**Psychology**

The weather person on the evening news reports that the average daily rainfall for the last six months is 10 inches. A farmer is trying to determine how the rain might affect his crops. a. standard deviation b significance test c correlation coefficient d criteron validity is ...

*April 5, 2013*

**Psychology**

The weather person on the evening news reports that the average daily rainfall for the last six months is 10 inches. A farmer is trying to determine how the rain might affect his crops.

*April 5, 2013*

**Psychology**

My answer is A.

*April 5, 2013*

**Psychology**

Professor Webb is interested in conducting a study on gender differences and coping with stress. He should begin his research by examining:

*April 5, 2013*

**algebra**

Thank you so much

*March 31, 2013*

**algebra**

y= -x^2-12x+28 A painter can use the formula A=2/3bh to estimate the area of space under the parabola. Calculate area in square ft under each arch ~ if there are 8 arches to be painted how many square ft must be painted ~ if 1 gallon paints 200 square ft , how many gallons ...

*March 31, 2013*

**Math**

Jimmy jumped into a lake from a 12-foot-high cliff with an initial upward velocity of 7 feet per second. Find the time in seconds it took Jimmy to enter the water. Use the model for vertical motion given by the equation h = -16 t squared + vt + s

*March 28, 2013*

**Chemistry**

this is the equetion for question 2 CaO+2NH4Cl-2NH3+H2O+CaCl2

*March 20, 2013*

**Chemistry**

1. The reaction CO+2H2-CH3OH was carried and it is found that only 332g of CH3Oh is actually produced when 407g CH3Oh was the expected yield. What is the Percent yield? 2. If 112g of CaO is reactied with an excess of NH4Cl and 64.0g of NH3 are produced, what is the percent ...

*March 20, 2013*

**curriculum development**

The size of a play/work area in the class made a noticeable difference in the time children stayed there and were engaged in complex play. The best size area is A) small and open B) large and open c) small and sheltered or d) large and sheltered. is B) large and open correct?

*March 19, 2013*

**Exceptional children**

i appreciate ure help! can u check this last one for me The final goal of a functional approach to managing prblem behavior is to a.) change the child b.) replace an inappropriate behavior with a good one. c.) change the environmet or d.) help child understand how to behave. i...

*March 19, 2013*

**Exceptional children**

Can you check my answers please Adaptive behaviors are a.) the same as fuctional skills b.) different from functional skills c.) exclude functional skills or d.) include functional skills. this is tricky for me but i'm guessing d.) include funtional skills. Does this sound...

*March 19, 2013*

**geometry**

If the measure of ÐDAB = 50°, and ÐDAC = 20°, what is ÐCAB?

*March 13, 2013*

**Chemistry**

If you have 1.90 mol of H_2 , how many grams of NH_3 can be produced?

*March 5, 2013*

**Chemistry**

If you have 1.90 mol of H_2 , how many grams of NH_3 can be produced?

*March 5, 2013*

**Physics**

Ok so F=MA thanks, I do appreciate especially since I am going to 35th reunion and went back to school. Much harder than I remembered. Again thanks

*March 5, 2013*

**Physics**

Sorry just re-learning after 30+ years.I had part of it answered however, the 4th and 5th question info was pertaining to questions 3 and 4 so I had to ask the question from the beginning. My answer was T = 1.585 s. for speed I calc 0.942/1.585s=0.594...right? my real problem ...

*March 5, 2013*

**Physics**

A 0.500 kg particle moves in a circle of R=0.0150 m at constant speed. The time for 20 complete revolutions is 31.7 s. What is the period T of the motion? What is the speed of the particle? What is the centripetal acceleration of the particle? What is the centripetal force on ...

*March 5, 2013*

**chemistry**

the equilibrium constant of the decomposition of NOCL is 1.6*10^-5. calculatethe concentration of all species at equilibrium if initially 3.52 mol of NOCL is placed in a 5.00 L container

*March 4, 2013*

**Chemistry**

The triprotic acid H3A has ionization constants of Ka1 = 6.8× 10–3, Ka2 = 8.1× 10–9, and Ka3 = 5.0× 10–12. Calculate the following values for a 0.0760 M solution of NaH2A [H+] = ? [H2A-]/[H3A]= ? Calculate the following values for a 0.0760 M ...

*February 26, 2013*

**Chemistry**

Phosphoric acid, H3PO4(aq), is a triprotic acid, meaning that one molecule of the acid has three acidic protons. Estimate the pH, and the concentrations of all species in a 0.100 M phosphoric acid solution. pKa1 = 2.16 pKa2 = 7.21 pKa3 = 12.32 [H3PO4] = ? [H2PO4-] = ? [HPO42...

*February 26, 2013*

**Chemistry**

What fraction of piperazine (perhydro-1,4-diazine) is in each of its three forms (H2A, HA–, A2–) at pH 7.22?

*February 26, 2013*

**Chemistry**

A certain indicator, HA, has a Ka value of 1.3 × 10-6. The protonated form of the indicator is blue and the ionized form is red. What is the pKa of the indicator? What is the color of this indicator in a solution with pH = 8? Blue, red, or purple?

*February 26, 2013*

**Chemistry**

This question has been bugging me for a long time. A rock contains a Pb-206 to U-238 mass ratio of .145 to 1.00. Assuming that it did not contain any Pb-206 at the beginning of its formation, determine its age. I assume from the other problems in my book that the 1/2 life is 4...

*February 23, 2013*

**chemistry**

However, when I try to find the rate constant I get 3.5. My book says 3.5^-.5. I don't know how they got this. .0069= (.010)^.5(.020)=approx 3.5 but the book says 3.5M^-1/2*s-1 Also I am wondering if there are three reactants in a problem, is there any difference how it is...

*February 23, 2013*

**chemistry**

I have a problem like this: CHCl3 + Cl2 = CCl4 +HCL This is the rate table: CHCL3 Cl2 Initial Rate .010 .010 .0035 .020 .010 .0069 .020 .020 .0098 .040 .040 .027 They want me to find the rate constant and the rate law.

*February 23, 2013*

**math**

1/72

*February 13, 2013*

**Math**

At a summer camp, one boy and one girl will be selected to lead the weekly activities. If there are 130 boys and 145 girls at the camp, how many different 2 person combinations of 1 boy and 1 girl are possible?

*February 5, 2013*

**Math**

On friday, a computer was priced at $800. on the following wednesday, the price was reduced by 15%. On the following friday, the price was further reduced by 20%. what percent of the original price was the final price ?

*February 5, 2013*

**Chemistry**

180

*January 29, 2013*

**Chemistry (Biochem)**

The true answers are 1,2 and 7. If the residues are polar then it only makes sense for them to come into contact with the solvent, as they are the hydrophilic amino acids.

*January 27, 2013*

**english**

The reason your voice matters is because its part of the way you want to be respected, spoken to, as well as you are part of a family of individuals. The fact that you have ideas of your own and you have values and an opinion is also why your voice should be heard. You have ...

*January 8, 2013*

**geometry**

LPG is stored in highly insulated spherical vessels in most oil refineriesif.If the inside diameter of one of these tanks is 11.4ft, find it's volume. Report your answer to the nearest one-tenth of a gal. Use r=3.14 and 1 cubic ft=7.5gal

*December 29, 2012*

**geometry**

find the volume of an industrial tank in the form of a horizontal cylinder whose radius is 2.6 yd, and whose length is 8.4 yd. rr=3.14

*December 29, 2012*

**chemistry**

When compound A is heated with acid compound B forms. Ahas the formula C3H8O and B is C3H6. When Ais oxidized compound D forms that is further oxidized to carboxylic acid. What are compounds A, B, and C.

*December 17, 2012*

**chemistry**

What is the pH of a solution prepared by dissolving 1.533 g HCl in water to make 420 mL of solution

*December 17, 2012*

**biology**

Following the usual pathway of circulation blood flows from the __________ to ___________, to_____________and to__________

*December 14, 2012*

**biology**

The ___________ ____________ supplies blood from the heart to all organs except the lungs

*December 14, 2012*

**biology**

Terms like punctiform and round relate to colonial ____________while smooth and curled relate to colonial___________

*December 14, 2012*

**biology**

Traditional phylogenetic results have been challenged by the results of _________________

*December 14, 2012*

**pre-algebra**

the perimeter of a pool is 150m. the width is 1/2 its length. what are the dimensions of the pool

*December 13, 2012*

**Chemisrty**

A 10.0 g sample of ice at -14.0°C is mixed with 124.0 g of water at 81.0°C. Calculate the final temperature of the mixture assuming no heat loss to the surroundings. The heat capacities of H2O(s) and H2O(l) are 2.08 and 4.18 J/g°C, respectively, and the enthalpy of...

*December 9, 2012*

**Accounting**

Harris company borrowed 65,000 by giving 10 year , 6% installment note to Cuba Bank The note requires annual payments of $8832 first payment occuring on the last day of the fiscal year. the first payment consists of interest of $3,900 and principal repayment of $4932, Issued ...

*December 6, 2012*

**Psychology**

the spillover effect is best explained in terms of the?

*November 17, 2012*

**nuclear chemistry**

wouldn't you divide by the speed of light squared? nuclear chemistry - andrew, Saturday, November 10, 2012 at 8:26pm E=mc^2 10^6 J/s are being produced (1Mw) 10^6 J/s = m (3.0e8 m/s) solve for mass to find amount of mass lost in one second. ~ .0033kg

*November 10, 2012*

**nuclear chemistry**

A typical nuclear reactor produces 1mw of power per day. What is the minimum rate of mass loss required to produce this energy. Don't know where to start

*November 10, 2012*

**chemistry**

never mind I got it thanks!

*November 8, 2012*

**chemistry**

This all that I have, what other information do I need?

*November 8, 2012*

**chemistry**

I need help with this lab. Write the equation for the decomposition of the hydrate, CuSO4*XH2O. Mass of crucible and hydrate: 93.000g Mass of crucible and pure salt: 91.196g I need to calculate the following: 1. mass of water in hydrate sample(g) 2. number of moles of water ...

*November 8, 2012*

**math**

Ashley needs $30 more in order to buy a concert ticket. she has saved money from her birthday and christmas presents. Her b-day present was 1.5 times the amount of her christmas present. Her b-day present was $60. if she saved 80% of her presents, how much does the concert ...

*November 6, 2012*

**math**

if 2 small containers and 1 large container together hold 10 cups of water, and 1 large container minus 1 small container leaves 4 cups of water, how many cups of water does the large container hold.

*November 6, 2012*

**Business Math**

Hafers, an electrical supply company, sold $4,800, 12%, 90-day note for a time extension of a bill for goods bought by Ron Prentice. On June 12, Scott discounted the note at Able Bank at 10%. What is the Maturity Value (MV).

*November 6, 2012*

**psychology**

For finals week, you had to be prepared for exams in english,math,spanish,italian,and history. how should the sequence of study be arranged to minimize the possibility of interference

*October 26, 2012*

**math**

3 out of 5 students own a pet. 6 out of 11 students own a pet. are the results proportional? explain reasoning

*October 23, 2012*

**Chemistry**

A vessel containing air (79% N2 and 21% O2) at 5bar and 280K is placed in a vacuum and a tiny hole is punched through the lid of the vessel. If the rate of effusion of O2 is 1.25x10^-7mol/s, at what rate is the nitrogen effusing? (in mol/s)

*October 4, 2012*

**math**

the hardware store is 5 blocks east of john's house. sean lives 3 blocks west of the bank, which is 4 blocks south and 2 blocks west of the hardware store. how many blocks and in what direction is sean's house from john's house?

*October 1, 2012*

**math**

the perimeter of rectangle y is equal to its area. rectangle z has the same perimeter as rectangle y. The length of rectangle z is 5 inches and the width is 3 inches. Explain how you can find the length and width of rectangle y.

*September 25, 2012*

**Physics**

You throw a ball downward from a window at a speed of 2.7 m/s. How fast will it be moving when it hits the sidewalk 2.9 m below?

*September 18, 2012*

**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 that's 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*