Sunday

May 1, 2016
Total # Posts: 7,560

**Math**

Let S(n) denote the sum of digits of the integer n. Over all positive integers, the minimum and maximum values of S(n)/S(5n) are X and Y, respectively. The value of X+Y can be written as a/b , where a and b are coprime positive integers. What is the value of a+b?
*February 19, 2013*

**Math**

John is building a fence that is 6 feet high and 18 feet wide to put around his garden. He has two sizes of boards that he can use. One is 2 feet by 6 feet and the other is 4 feet by 6 feet. John can put the boards either horizontally or vertically and he has lots of boards of...
*February 19, 2013*

**Maths**

Siuan's grandmother recently signed up for a twitter account. She only follows five people - her five grandchildren. Each day, each of her grandchildren make two tweets and at the end of the day Siuan's grandmother gets an e-mail that lists all ten tweets in ...
*February 19, 2013*

**Math**

Killer robots are trying to take over the world. They know the password to the doomsday weapon is 5 digits long and contains either 0 or 1, and either 2 or 3, and either 4 or 5, and either 6 or 7, and either 8 or 9. If the robots can enter 5 passwords per second, how long (in ...
*February 19, 2013*

**math**

"The area of a rectangle is 360m2. If its lengh if increased by 10m and its width is decreased by 6m, then its area does not change. Find the perimeter of the original rectangle." I need to use the "guess and test" or the "draw a diagram" method ...
*February 18, 2013*

**Physics**

The Royal Gorge bridge over the Arkansas River is 310.0 m above the river. A 59.0-kg bungee jumper has an elastic cord with an unstressed length of 62.0 m attached to her feet. Assume that, like an ideal spring, the cord is massless and provides a linear restoring force when ...
*February 17, 2013*

**Chemistry**

You use 2.80 g of NaHCO3, and determined that 2.83 g of carbon dioxide ar produced. Convert the mass of NaHCO3 to moles: Convert the mass of CO2 to moles:
*February 16, 2013*

**Chemistry**

Some of your reaction mixture splashed out of the beaker when you dropped the tablets into the acetic acid. How would this affect your measurements? Woud your final calculated mass of sodium bicarbonate in the tablet be artificially high or low as a result of this splashing?
*February 16, 2013*

**dilution please help**

How to use serial dilution to dilute a stock solution at 15000 fold dilution?
*February 16, 2013*

**Dilution**

Please, if possible, check if my method of dilution is correct Problem: Given a very concentrated liquid PBS, dilute it to 1:15,000 My approach is to use serial dilution First: dilute it 15x (50ul of PBS + 750ul of water)... this will give 1:15 Second: dilute 10xfold more (...
*February 15, 2013*

**jones**

I have a unscramble analogies worksheet that I can't answer. Here are the analogies: ________:judical branch [eempusr ructo] radius:______[meeairtd] brass instruments:_____[stoaercrh] _______:poem[anzsat] _______:pants[bowaerrd] thank yo
*February 14, 2013*

**Chemistry**

A solvent has a molar mass of 37.2 g/mol and a normal boiling point of 111.2 oC. The boiling point elevation constant, K b , for this solvent is 1.58 oC/m. If 18.7 g of a nonelectrolyte having a molar mass of 20.5 g/mol are mixed with 170.0 g of the solvent, what is the ...
*February 14, 2013*

**College**

A bod of 10kg is traveling in straight line at 10m/s (a)what is de momentum?(b)what is de average force required to increase its velocity 4rom zero to 20m/s in 4seconds?
*February 13, 2013*

**Math**

Well, you copied 5 and 8 wrong from the 2nd and 3rd problem to the final calculation.
*February 12, 2013*

**Physics**

During an action potential, Na^+ ions move into the cell at a rate of about 3x10^-7 mol/m^2*s. How much power must be produced by the "active Na^+ pumping" system to produce this flow against a +30-mV potential difference? Assume that the axon is 40cm long and 30um ...
*February 12, 2013*

**Pre cal**

From a point A is 8.20 meters above level ground,the angle of elevation of the top of a building is 31degrees 20 min and the angle of depression of the base of the building is 12degree 50 min. Approximate the heighth of the building
*February 11, 2013*

**Chemistry**

Naphthalene combustion can be used to calibrate the heat capacity of a bomb calorimeter. The heat of combustion of naphthalene is -40.1 kJ/g. When 0.8210 g of naphthalene was burned in a calorimeter containing 1,000. g of water, a temperature rise of 4.21Ã‚Â&...
*February 11, 2013*

**Math**

two sides of a triangle have the ratio of 3:4. The hypotenuse is 20. What are the measures of the two other sides?
*February 11, 2013*

**Physics**

A dropping ball initial at rest is dropped 1.5m; calculate a) the traveling time of the ball and b) its velocity just before reaching the ground.
*February 10, 2013*

**probability**

John has 3 unique coins such that the probability of obtaining a head when the coin is flipped is 1/10, 2/10 and 3/10, respectively. If he flips each of the 3 coins once, the probability that at least 1 heads appears is p. What is the value of 1000p?
*February 10, 2013*

**probability**

John has 3 unique coins such that the probability of obtaining a head when the coin is flipped is 110, 210 and 310, respectively. If he flips each of the 3 coins once, the probability that at least 1 heads appears is p. What is the value of 1000p?
*February 10, 2013*

**Physics please help**

During an action potential, Na^+ ions move into the cell at a rate of about 3x10^-7 mol/m^2*s. How much power must be produced by the "active Na^+ pumping" system to produce this flow against a +30-mV potential difference? Assume that the axon is 40cm long and 30um ...
*February 10, 2013*

**Physics please help**

Can you please help out am still stuck one this
*February 10, 2013*

**Physics please help**

During an action potential, Na^+ ions move into the cell at a rate of about 3x10^-7 mol/m^2*s. How much power must be produced by the "active Na^+ pumping" system to produce this flow against a +30-mV potential difference? Assume that the axon is 40cm long and 30um ...
*February 10, 2013*

**physics**

8. Electric field lines arising from two small charged particles P and Q. Consider the following two statements: i.The charge on P is smaller than the charge on Q. ii.The electrostatic force on P is smaller than that on Q. Which of the above statements are true? A) Only i. B) ...
*February 9, 2013*

**Pre-calculus **

a) A particular ball always rebounds 3/5 the distance it falls. If the ball is dropped from a height of 5 meters, how far will it travel before coming to a stop? Explain the reasoning. b) Prove that if a1, a2, a3, ... is a geometric sequence,then ln(a1), ln(a2), ln(a3)... is ...
*February 9, 2013*

**Chemistry**

A student mixes 85.1 g of water at 69.6Â°C with 58.1 g of water at 22.0Â°C in an insulated flask. What is the final temperature of the combined water?
*February 9, 2013*

**Algebra**

suppose you invest $1100 at an annual interest rate of 4.3% compounded continuously. How much will you have in the account after 15 years?
*February 8, 2013*

**SS**

Warm
*February 7, 2013*

**Limit**

(x2-27)/(x-3) as x tends to 3
*February 6, 2013*

**Statistics**

A telephone company's records indicate that private customers pay on average $17.10 per month for long-distance telephone calls. A random sample of 10 customers' bills during a given month produced a sample mean of $22.10 expended for long-distance calls and a sample ...
*February 5, 2013*

**Statistics**

Which of the following conditions doesn't need to be met before you can use a two-sample procedure? The responses in each group are independent of each other. Each group is considered to be a sample from a distinct population. The same variable is measured in both samples...
*February 5, 2013*

**chemistry help !!!!!!!!!!!!!!!!**

complete the following paragraph relating to the enzyme,b -galactosidase .this enzyme hydrolyses the disaccharide lactose to constituent monosaccharides ,galactose and glucose ,drag and drop the approprite words into the correct space. the enzyme ,B-galactosidase is added to a...
*February 2, 2013*

**chemistry help !!!!!!!!!!!!!!!!**

complete the following paragraph relating to the enzyme,b -galactosidase .this enzyme hydrolyses the disaccharide lactose to constituent monosaccharides ,galactose and glucose ,drag and drop the approprite words into the correct space. the enzyme ,B-galactosidase is added to a...
*February 2, 2013*

**calculus 1**

y-28=(18x-3x2)(x-2)
*January 31, 2013*

**Math!!!**

I have a input output table and I can't figure out the rule here is the chart X. Y _______________ 1. | 3 4. | 7 7. | 11 Can u figure it out I'm having a really hard time with this problem!!!!
*January 30, 2013*

**Physics / Heat Transfer**

How much heat must be removed from a 200 g block of copper to lower its temperature from 302 oF to 68 oF? Specific heat of copper: c = 0.092 kcal/(kg K) a. 2.4 kcal b. 2400 kcal c. 18.4 kcal d. 12 kcal e. 26 kcal
*January 30, 2013*

**MATH**

4[23 - (6 + 4)]
*January 29, 2013*

**MATH**

4[23 - (6 + 4)]
*January 29, 2013*

**ACT/SAT MAP PREP**

- t^5 u^5 v^5/ tuv =????????
*January 29, 2013*

**math**

write the number in words 84,508
*January 29, 2013*

**computer science**

Write a method printBackwards that prints an array of integers in reverse order, in the following format. For the array {1, -3, 4, 7, 2}: element [4] is 2 element [3] is 7 element [2] is 4 element [1] is -3 element [0] is 1
*January 29, 2013*

**5th grade math**

Using input output tables input 3 4 5 6 0 10. Output 9 16 25 36 0 100 what is the input output rule?
*January 29, 2013*

**math**

thank you
*January 27, 2013*

**math**

The sum of four consecutive multiples of 5 is 230. What is the greatest of these numbers ?
*January 27, 2013*

**math**

1. If 2x/5y=6,what is the value of y, in terms of x ? 2. 11/4-a=3 , What is the value of a in the equation ?
*January 27, 2013*

**Math**

Thank u :)
*January 25, 2013*

**Math**

Working with linear equations: 3(2x+1) - 4 (x+2) = 9
*January 25, 2013*

**nursing**

For example: Kim, a neonatal ICU nurse, has cared for baby Sara for the past month. Baby Sara is about to be discharged today in good health. The baby’s parents want to give Kim a personal gift as an expression of their appreciation and have also invited Kim to the baby&#...
*January 24, 2013*

**math**

thank you , Ms.Sue
*January 23, 2013*

**math**

3. x + 11 4. H x 15
*January 23, 2013*

**math**

thank you
*January 23, 2013*

**math**

1. two times the number of windows 2. 81 increased by n 3.eleven more than a number 4. $15 times the number of hours
*January 23, 2013*

**math**

Write a variable expression for each word phrase. 1. two times the number of windows 2. 81 increased by n 3.eleven more than a number $15 times the number of hours
*January 23, 2013*

**Math**

A woman invested $15,000, part at 7% annual interest and the rest at 8%. If she earned $1,100 in income over a one-year period, how much did she invest at 7%?
*January 23, 2013*

**Physics**

Two particles are fixed along a straight line, separated by a distance 6.0 cm. The left one has a charge +2.0 nC and the right one has a charge of +6.0 nC. You must try to locate a point where the electric field is zero. (a) What is the location of the point? (b) How far from ...
*January 21, 2013*

**chemistry help !!!!!!!!!!!!!!!!**

Benzoic acid react with NH2 group Draw the product of this reaction, name the new functional group produced, state the type of reaction that has occurred, name any other products of the reaction and briefly explain how you arrived at your answer.( one or two sentences.)
*January 21, 2013*

**Physics**

True or false?equal masses of two different gases placed in containers of equal volume at equal temperature must exert equal pressures
*January 21, 2013*

**chemistry help !!!!!!!!!!!!!!!!**

Identify 4 functional group: HO-HO-BENZENE RING-CH2-CH-NH2-C=O-OH 1)carboxylic acid functional group 2)amine functional group 3)alcohol functional group i only know three is anyone can tell me the last functional group.please
*January 21, 2013*

**chemistry help !!!!!!!!!!!!!!!!**

Identify 4 functional group: O || HO CH2 C \ / \ / \ Benzen ring CH OH / | HO NH2 1)carboxylic acid functional group 2)amine functional group 3)alcohol functional group i only know three is anyone can tell me the last functional group.please
*January 21, 2013*

**Chemistry**

What mass of glucose can be produced from a photosynthesis reaction that occurs using 21.2 mol CO2? Answer in units of g
*January 20, 2013*

**Pol 201 American National Goverment**

9. The Connecticut Plan was called the Great Compromise because (Points : 1) it allowed states with larger populations to have more representatives in the House and each state to have the same number of votes in the Senate. it allowed slave states to keep their slaves. it ...
*January 20, 2013*

**Chemistry/Calculus**

Thank you, sir. However, I stillmust be doing something wrong because I am not getting the answer. My calculator will give me an error if I do it that way. On my TI-30 I punch in 2nd button, the hit Ln, then (1.00 X 10-2 / 1.65 X 10-2) and get 1.83...
*January 19, 2013*

**Chemistry/Calculus**

I have a question about how to plug in numbers on my calculator (TI-30XIIS) to get an answer. How would I put in my calculator... ln 1.00X 10-2 mol/L /1.65 X 10-2 mol/L to get-0.501? I keep getting the wrong answer...
*January 19, 2013*

**math**

1. solve for y: 2y-3<9+y 2. solve for x: 7-2x>3y
*January 19, 2013*

**English**

How did the elephant save the life oe porus.
*January 19, 2013*

**thermal physic**

What is the average translational kinetic energy of one mole Of gas molecule in an ideal gas at 37degree celsius
*January 19, 2013*

**Chemistry**

55.34g/mol^3
*January 17, 2013*

**Chemistry**

An element crystallizes in a body-centered cubic lattice. The edge of the unit cell is 2.77 , and the density of the crystal is 8.65 . Find the atomic weight of the element.
*January 17, 2013*

**economics**

How does a budget differ when you have an irregular income vs. a predictable income? irregular income is monthly budget.
*January 16, 2013*

**economics**

Jesse and Kimberly recently graduated from college and are starting a family. Currently, they are just making ends meet with their $45,000 salary. They want to contribute the maximum amount (currently $2,000) to fully fund an Educational Savings Account when their baby is born...
*January 16, 2013*

**economics**

thanks...
*January 16, 2013*

**economics**

Kimberly works for a well known financial company as a sales representative. She earns a small base salary but receives commission off every product she sells. Kimberly has basic living expenses in addition to a student loan. She wants to start adding to her Roth IRA and buy a...
*January 16, 2013*

**Chemistry**

At room temperature, ethanol's density is 0.789 g/mL while water's density is 0.997 g/mL. When a few milliliters of ethanol are added to water, the two liquids mix. A student is given a unknown liquid at room temperature and experimentally determines its density to be ...
*January 16, 2013*

**physics**

the magnitude of the tongue produced by a 3.0n force applied to a door at a perpendicular distance of 0.25 m from the hinge
*January 15, 2013*

**Geometry**

let x = witdth 4x+2 = length perimeter of rectangle = 2L + 2W substitute: 34 = 2(4x+2) +2x 34 = 8x + 4 + 2x 34-4 = 10x 10x = 30 x = 3 - width length = 4(3) + 2 = 12 + 2 = 14 :)
*January 15, 2013*

**math**

error.. that's supposed to be -10x = -1-6 -10x = -7 x = 7/10 im so sorry..
*January 15, 2013*

**math**

y = 2-4x Substituting, 3(2-4x) + 2x = -1 6-12x + 2x = -1 -10x = -1-5 -10x = -6 x = 6/10 or 3/5
*January 15, 2013*

**PLEASE HELP ME IN THIS PHYSICS PROBLEM**

A heat transfer of 9.5 x 10^5 J is required to convert a block of ice at -15°C to water at 15°C. What is the mass of the block of ice?
*January 14, 2013*

**chemistry**

how methane is produced or where it comes from?
*January 14, 2013*

**math**

If one side of a triangle is of length x and another side is of length x+6,which of the following could not be the lenght of the third side? a.5 b.7 c.9 d.11 e.13
*January 13, 2013*

**math**

The lengths of two sides of a parallelogram are 3 are 5. which of the following is a possible value for the length of a diagonal of the parallelogram? a.2 b.2 c.8 d.10 e.15
*January 13, 2013*

**math**

thank you, Reiny
*January 13, 2013*

**pre algebra**

hi i need some help
*January 13, 2013*

**Discreete math problem**

Determine the quotient q and remainder r for each of the following. where a is the dividend and b is the divisor. a=23, b=7
*January 11, 2013*

**chemistry**

1211
*January 11, 2013*

**physics**

A 2kg and a 4kg hang freely at opposite ends of a light inextensible string which passes over a small and light pulley fixed to a rigid support calculate the acceleration of the system
*January 11, 2013*

**Math**

Factor pls show me steps thank u! (X-1)(x+2)^2-(x-1)^2(x+2)
*January 10, 2013*

**chemistry??**

Oxidising and reduction- Chemistry? Oxidation and reduction can be described as the loss and/or gain of electrons from an ion or atom (species) in a chemical reaction. For thefollowing aqueous reaction, select the species that is oxidized and similarly the one that is reduced...
*January 10, 2013*

**math**

300 hundred kids attend a dance. The ratio of boys to girls is 6 to 4. If 30 boys and 20 girls leave, what is the new ratio of boys to girls still at the dance
*January 10, 2013*

**chemistry please help**

thanks
*January 10, 2013*

**chemistry please help**

The reaction between hydrogen and chlorine gases gives hydrogen chloride gas in the following reaction: H2(g) + Cl2(g) = 2HCl(g) It is found experimentally that 1 mole of H2 gas reacts with 1 mole of Cl2 gas at constant temperature and pressure, to release 184 kJ of heat. What...
*January 10, 2013*

**chemistry hellllllllllllllllllp**

you mean Al^3+ is oxidized ,Ag^+ is reduced.
*January 10, 2013*

** PHYSICS HELP**

Back in the stage coach era, iron rims were placed on wooden wheels by shrink-fitting. Suppose that the wheel has a diameter of 100.00 cm, whereas the rim has an inside diameter if 99.75 cm at 20°C. How hot must the iron rim be heated if it is to be slid over the wheel? (...
*January 9, 2013*

**physics**

A 4.75 mass was dropped from a certain height and achieved a maximum velocity of 7.68 m/s just before striking the ground. Determine the height from which the mass was dropped. Ignore air drag.
*January 8, 2013*

**mechanical science**

a c accelerates from rest in a straight line. after 12 seconds, it's velocity is measured as 42 m/s. use one of the linear equations of motion to calculate the car's acceleration
*January 8, 2013*

**Chemistry**

Chlorine gas + aqueous sodium bromide --> aqueous bromine + aqueous sodium chloride. I got: Cl2+2NaBr2(aq)-> Br2(aq)+2NaCl2(aq) Is this right ?
*January 7, 2013*

**Ant**

10. Diffusion means: a. cultural traits are expressions of our biology. b. the environment is responsible for culture change. c. cultures borrow ideas, material items, and concepts from each other. d. people are often unwilling to move to new locations.
*January 6, 2013*

**Chemistry**

Thanks
*January 6, 2013*