Thursday

August 21, 2014

August 21, 2014

Total # Posts: 2,289

**chemistry **

What is the wavelength of the transition from n = 2 to n = 1 for Li2+? Li2+ is a hydrogen-like ion. Such an ion has a nucleus of charge +Ze and a single electron outside this nucleus. The energy levels of the ion are -Z2RH/n2, where Z is the atomic number. nm In what region of...
*November 7, 2010*

**chemistry **

What is the de Broglie wavelength of an oxygen molecule, O2, traveling at 503 m/s?
*November 7, 2010*

**chemistry **

Calculate the frequency of electromagnetic radiation emitted by the hydrogen atom in the electron transition from n = 7 to n = 6.
*November 7, 2010*

**math **

jasmine is helping her father plant trees to create a border around their back yard jasmine plants a treesevery 25 and her father plants a tree every 15 minutes if they started together how long before they would finsh planting a treee at the same time
*November 7, 2010*

**math **

slove the folowing eqaution negtive 23=x+35
*November 7, 2010*

**geometry**

the quadrilateral has a pweimeter of 60 meters. mp and no are congruent the length of mn is 10 meters and the length of no is 15 meters what is the length of po
*November 7, 2010*

**analytical chemistry**

blank is used to dissipate the error brought about by impurities. What is the other reason of using blank in Mohr method?
*November 5, 2010*

**English**

I have a few question on linking verbs: 1. I am fond of both kinds of comics. linking verb - fond? 2. Joseph Pulitzer was the first to publish color funnies. linking verb - was? 3. The sales of his newspaper were high. linking verb - sales 4. Sunday Funnies soon became part of...
*November 2, 2010*

**physics**

What is the approximate mass of air in a living room 6.0 m times 3.9 m times 2.7 m?
*November 1, 2010*

**PHYSICS ---HELP!**

Suppose there is a circular metal disk spinning at a constant angular velocity. Now imagine near to, but not in contact with the first disk, there is an identical metal disk spinning at the same angular velocity but in the opposite direction (ie. W1 = -w2) and the surfaces are...
*November 1, 2010*

**Physics-- Please Help!!**

Suppose there is a circular metal disk spinning at a constant angular velocity. Now imagine near to, but not in contact with the first disk, there is an identical metal disk spinning at the same angular velocity but in the opposite direction (ie. W1 = -w2) and the surfaces are...
*November 1, 2010*

**chemistry **

How much heat is released when a mixture containing 12.6 g CS2 and 12.6 g Cl2 reacts by the following equation? CS2(g) + 3 Cl2(g) → S2Cl2(g) + CCl4(g) ΔH° = −230. kJ
*October 31, 2010*

**chemistry **

How many grams of oxygen gas are required to produce 7.46 kJ of heat when hydrogen gas burns at constant pressure to produce gaseous water? 2 H2(g) + O2(g) → 2 H2O(g) ΔH = −484 kJ Liquid water has a heat of vaporization of 44.0 kJ per mole at 25°C.
*October 31, 2010*

**chemistry **

Calculate the heat released when 4.260 L Cl2 with a density of 2.46 g/L at 25°C reacts with an excess of sodium metal to form solid sodium chloride at 25°C.
*October 31, 2010*

**chemistry **

A 19.5-g sample of a metal was heated to 61.67°C. When the metal was placed into 26.5 g of water in a calorimeter, the temperature of the water increased from 25.00°C to 30.00°C. What is the specific heat of the metal?
*October 31, 2010*

**Chemistry **

Hydrogen cyanide is a highly poisonous, volatile liquid. It can be prepared by the following reaction. CH4(g) + NH3(g) → HCN(g) + 3 H2(g) What is the heat of reaction at constant pressure? Use the following thermochemical equations. N2(g) + 3 H2(g) → 2 NH3(g) Δ...
*October 31, 2010*

**Math**

An auditorium has 50 rows of seats. The first row has 20 seats, the second row has 21, the third row has 22 seats, and so on, each row having one more seat than the previous row. How many seats are there all together? a. write 2 different expressions for the total number of ...
*October 29, 2010*

**trig**

If a=8, the angle C=50 degrees and the angle A=35 degrees find the other angle B and the remaining b and c sides. Give your answer to at least 3 decimal places.
*October 29, 2010*

**physics**

Consider a hoola-hoop of radius R and it is spinning about its symmetry axis at a constant angular velocity. Now, I double its mass and halve its angular velocity. What is the new angular momentum in terms of the initial angular momentum?
*October 29, 2010*

**physics**

With acceleration of 2500 m/s2, how long will it take to rreach speed of light
*October 29, 2010*

**physics**

With acceleration of 2500 m/s2, how long will it take to rreach speed of light
*October 28, 2010*

**English**

Thank you so much. I think I get it!
*October 28, 2010*

**English**

Zoo keepers harvest bamboo for Pandas harvest = transitive? In China people eat the tender shoots as a vegetable. eat = transitive?
*October 28, 2010*

**English**

last two, I think I am getting it... Zoo keepers harvest bamboo for Pandas harvest = transitive? In China people eat the tender shoots as a vegetable. eat = intransitive?
*October 28, 2010*

**English**

Asian farmers live in bamboo houses? live = intransitive? Their sandals are made from bamboo strips. made = intransitive? Peoples sometimes sleep on bamboo mats. sleep = intransitive? In some countries, bamboo cages hold animals. hold = transitive?
*October 28, 2010*

**English**

Asian farmers live in bamboo houses? live = transitive? Their sandals are made from bamboo strips. made = transitive? Peoples sometimes sleep on bamboo mats. sleep = transitive? In some countries, bamboo cages hold animals. hold = transitive?
*October 28, 2010*

**English**

The Size might suprise you. suprise = transitive Some reach a height of 120 feet. reach = transitive The Japanese also make flutes from these stems. make - transitive
*October 28, 2010*

**English**

I am trying to figure out transitive or intransitive.... It is related to wheat, oats and barley. related = intransitive? The stems measure a foot in diameter. measures - transitive? Engineers strengthen concrete with it. Intransitive?
*October 28, 2010*

**Chemistry**

What is the temperature (in kelvins) at which 0.0260 mol occupies 1.00 L at 0.563 atm?
*October 27, 2010*

**Biology**

also located on the X chromosome is a gene that codes for deafness. This gene is recessive. a black female cat that is heterozygous for deafness (Dd) is crossed with a yellow cat that is not deaf What is the Punnet Square . and must use two letters on the x chromosome
*October 27, 2010*

**algebra**

what does x equal in this equation?1/2+7x/10=13/20
*October 27, 2010*

**Biology**

Thanks
*October 27, 2010*

**Biology**

Why do we perform aerobic respiration when we're resting and both aerobic and anaerobic respiration while we're running?
*October 27, 2010*

**math**

A low ha this paper sux ):
*October 27, 2010*

**math**

352$ for mae assurian and sally got $4.44 cents for 148 newspapers.
*October 26, 2010*

**Applied statistics for business and economics**

I apologize, 3 of the above answers are not correct. * a. 0.0498 * b. 0.0000 c. correct * d. 0.0038 e. correct f. correct
*October 24, 2010*

**Applied statistics for business and economics**

a. 0.9998 b. 0.0002 c. 0.0504 d. 0.0224 e. 3 cards f. 1.731877594 (rounded 1.7319)
*October 24, 2010*

**Math**

Thank you!
*October 22, 2010*

**Math**

For what values of k does the function f(x)=(k+1)x^2+2kx+k-1 have no zeros? One zero? Two zeros?
*October 22, 2010*

**Physics**

average acceleration in m/s squared
*October 21, 2010*

**Physics**

A sports car accelerates from rest to 89 km/h in 6.1s . What is its average acceleration in
*October 21, 2010*

**Physics**

A sports car accelerates from rest to 89 km/h in 6.1s . What is its average acceleration in
*October 21, 2010*

**Physics**

If you are driving 100km/h along a straight road and you look to the side for 1.9s , how far do you travel during this inattentive period?
*October 21, 2010*

**physics**

If you are driving 100 along a straight road and you look to the side for 1.9 , how far do you travel during this inattentive period?
*October 21, 2010*

**Math**

Determine the domain and range of f(x)=-sqrt(x+3) and the equation of the inverse.
*October 21, 2010*

**Math**

If f(x)=x^2-6x+14 and g(x)=-x^2-20x-k, determine the value of k so that there is exactly one point of intersection between the two parabolas.
*October 21, 2010*

**Biology**

What does the net movement of solutes/solvents during osmosis and diffusion mean?
*October 20, 2010*

**chemistry**

A coal burning plant that burns 4 metric tons of coal containing 2% sulfur (S) requires 1 metric ton of wet limestone (calcium carbonate) to remove 90% of the sulfur. The process prevents most of the sulfur from being emitted as sulfur dioxide to the air by producing calcium ...
*October 20, 2010*

**chemistry**

A coal burning plant that burns 4 metric tons of coal containing 2% sulfur (S) requires 1 metric ton of wet limestone (calcium carbonate) to remove 90% of the sulfur. The process prevents most of the sulfur from being emitted as sulfur dioxide to the air by producing calcium ...
*October 20, 2010*

**physics**

find the frictional force between an air hockey puck and the table, assume u air = 1.8 X 10^-5 kg/ms, the puck is 0.013 above the table, the puck has an area of 25 cm^2
*October 19, 2010*

**chemistry**

A coal burning plant that burns 4 metric tons of coal containing 2% sulfur (S) requires 1 metric ton of wet limestone (calcium carbonate) to remove 90% of the sulfur. The process prevents most of the sulfur from being emitted as sulfur dioxide to the air by producing calcium ...
*October 19, 2010*

**chemistry**

A coal burning plant that burns 4 metric tons of coal containing 2% sulfur (S) requires 1 metric ton of wet limestone (calcium carbonate) to remove 90% of the sulfur. The process prevents most of the sulfur from being emitted as sulfur dioxide to the air by producing calcium ...
*October 19, 2010*

**precalc**

find where f(x)<0 and f(x)>0 f(x)=xlnx-2x
*October 18, 2010*

**Math**

Given f(x)=7-2(x-1)^2, x>= 1, determine f inverse (5).
*October 18, 2010*

**Math**

Given f(x)=2x^2-1, determine the equation of the inverse.
*October 18, 2010*

**Math**

Given f(x)=7-2(x-1)^2, x>= 1, determine f inverse (5).
*October 18, 2010*

**Chemistry**

what is the wavelength of the photon emitted when an electron drops from a 4p orbital to a 2p orbital in a hydrogen atom
*October 18, 2010*

**Biology**

A cell has a salt concentration of 0.2 %. If it is placed into a solution with a salt concentration of 0.1 %. a) What change will occur to the salt concentration inside the cell? b)What change will occur to the water concentration inside the cell? c)What condition will ...
*October 18, 2010*

**Economics**

True or false: The US must remove tariffs and quotas to open trade with foreign countries. Consider the following issues: The definition of tariffs and quotas. The strength of the dollar on domestic and global economies. Benefits from tariffs or quotas, including examples. ...
*October 18, 2010*

**Chemistry**

Given a 2.5 kg solution of phosphoric acid and water (56 % phophoric acid, by mass), calculate the number of moles of phosphoric acid.
*October 18, 2010*

**Chem**

I got 100125 is that correct?
*October 17, 2010*

**Chem**

The specific heat capacity of aluminum is .89 J/y degrees C. How much heat is required to change the temp of 1500g aluminum pan from 25 degrees C to 100 degrees C?
*October 17, 2010*

**Chem**

The specific heat capacity of aluminum is .89 J/y degrees C. How much heat is required to change the temp of 1500g aluminum pan from 25 degrees C to 100 degrees C?
*October 17, 2010*

**calculus**

Find the equation of a cubic function that gives you the surface area of the cans given a set volume. The set volume is 300ml
*October 17, 2010*

**Photography**

What's the difference between the setting of the enlarger height and focusing the image? Aren't both of the dealing with the light that shines onto the baseboard?
*October 17, 2010*

**Math**

What does it mean by: Show that the "value of 3x^2-6x+5" cannot be less than 1. ?
*October 15, 2010*

**Physics**

Oh! thanks! I understand it now :D
*October 15, 2010*

**Physics**

So it's 20 x 0.8=16?
*October 15, 2010*

**Physics**

A certain force made a 5.0 kg mass accelerate at 4.0 m/s^2. This same force made another object accelerate at only 0.8 m/s^2. Find the mass of the second object. I have no idea how to do this. Do i use m=1/a? What do i do?
*October 15, 2010*

**Physics- Newton's 1st and 2nd Law**

Thank you so much for the help!!
*October 14, 2010*

**Physics- Newton's 1st and 2nd Law**

Please help me :( Briefly explain the following scenario's using Newton's first law. a) Trevor wants to tow Kevin's car with his truck. He attached a small tow rope between the vehicles and leaves the rope slack (loose). Trevor quickly accelerates forwards making ...
*October 14, 2010*

**Math**

What are the vertical and horizontal stretch/compressions for the functions h(x)=1/(5x) and k(x)=|0.4x| ?
*October 11, 2010*

**physics**

A car drives straight off the edge of a cliff that is 56 m high. The police at the scene of the accident note that the point of impact is 129 m from the base of the cliff. How fast was the car traveling when it went over the cliff?
*October 11, 2010*

**Physics**

I understand the mass should be divided by the density for the required volume. I dont think that I am using the correct numbers. I came up with a volume of 172800 or 1.7 x 10^5 but the answer is incorrect. Can you please help?!! I did (1000V)(10)(500) = 1.7x 10^5
*October 11, 2010*

**Physics**

where would I use the 9.8m/s^2? And the density is which number?
*October 11, 2010*

**Physics**

To store the energy produced in 1.5 hour by a 160 MW (160 10^6 W) electric-power plant, how many cubic meters of water will have to be pumped from the lower to the upper reservoir? Assume the upper reservoir is 500 m above the lower and we can neglect the small change in ...
*October 11, 2010*

**Math**

A 5 m stepladder propped against a classroom wall forms an angle of 30 degree with the wall. Exactly how far is the top of the ladder from the floor? Express your answer in radical form. What assumption did you make?
*October 10, 2010*

**math**

find a function y=ax^2+bx+c whose graph has an x-intercept of 1, a y-intercept of -2, and a tangent line with slope -1 at the y-intercept.
*October 9, 2010*

**Math**

Given any right triangle with an acute angle theta, a) Explain why csc theta is always greater than or equal to 1 b) Explain why cos theta is always less than or equal to 1
*October 8, 2010*

**hist**

who were the pilgrims and what did they believe?
*October 8, 2010*

**algebra**

A brick border that is x feet wide is built around a rectangular patio. The patio is 6 feet wide and 8 feet long. The combined area of the patio and the brick border is 120 square feet. What is the width of the brick border?
*October 7, 2010*

**algebra**

If the area of a square is 9x2-12xy+4y2, what is the perimeter of the square in terms of x and y. *its 9x squared and 4y squared i have several problems like this on my homework if you show me how to do this one im sure i could figure out the rest
*October 6, 2010*

**algebra**

Elliot is 5 times as old as Sid. Ten years from now, Elliot will be at least 3 times as old as Sid will be then. At least how old is each person now?
*October 6, 2010*

**Physics**

You are driving to the grocery store at 14.8 m/s. You are 140.0 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.440 s and that your car brakes with constant acceleration. You are 133 m from the intersection when you begin to apply ...
*October 6, 2010*

**Physics**

i do not think that is correct because i am getting the incorrect answer.
*October 6, 2010*

**Physics**

You are driving to the grocery store at 14.8 m/s. You are 140.0 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.440 s and that your car brakes with constant acceleration. You are 133 m from the intersection when you begin to apply ...
*October 6, 2010*

**Physics**

You are driving to the grocery store at 14.8 m/s. You are 140.0 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.440 s and that your car brakes with constant acceleration. You are 133 m from the intersection when you begin to apply ...
*October 6, 2010*

**Physics**

A speedboat starts from rest and accelerates at +2.07 m/s2 for 7.00 s. At the end of this time, the boat continues for an additional 6.00 s with an acceleration of +0.523 m/s2. Following this, the boat accelerates at -1.55 m/s2 for 8.00 s. What is the velocity of the boat at t...
*October 6, 2010*

**Physics**

nope :(
*October 5, 2010*

**Physics**

kk got that. did you get number 18?
*October 5, 2010*

**Physics**

okay ! and which q'n did u get 255 m for?
*October 5, 2010*

**Physics**

k i got this one.. find the t it takes for each runner using t=d/v....then subtract the times, and you have the answer !
*October 5, 2010*

**Physics**

A speedboat starts from rest and accelerates at +2.07 m/s2 for 7.00 s. At the end of this time, the boat continues for an additional 6.00 s with an acceleration of +0.523 m/s2. Following this, the boat accelerates at -1.55 m/s2 for 8.00 s. What is the velocity of the boat at t...
*October 5, 2010*

**Physics**

You are driving to the grocery store at 14.8 m/s. You are 140.0 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.440 s and that your car brakes with constant acceleration. How far are you from the intersection when you begin to apply...
*October 5, 2010*

**Physics**

alrighttyy. did u get number 13, 14 or 18?
*October 5, 2010*

**Physics**

okay thanks ! was your velocity really small and negative then?
*October 5, 2010*

**Physics**

okay but what does 'u' refer to? Also, for question #7, how did you figure out the total velocity for the entire trip?
*October 5, 2010*

**Physics**

oh okay i got that ! thanks. for the second part..how long it takes to reach the bottom.. do u use t = d/v?
*October 5, 2010*

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