Wednesday

September 28, 2016
Total # Posts: 575

**chemistry**

does elements with low energy have high frequency?

*September 15, 2011*

**Chemistry**

What is the Wavelength( in nm) of the least energetic spectral line in the infrared series of the H atom? I don't understand how to find the least energetic spectral line?

*September 10, 2011*

**physics**

A man pushing a mop across a floor causes the map to undergo two displacements. The first has a magnitude of 200 cm and makes an angle of 120° with the positive x axis. The resultant displacement has a magnitude of 240 cm and is directed at an angle of 60.0° to the ...

*September 10, 2011*

**Chemistry**

Covalent bonds in a molecule absorb radiation in the IR region and vibrate at characteristic frequencies. a) The C---O bond absorbs radiation of wavelength 9.6um. What frequency (in s-1) corresponds to that wavelength? b) The H---Cl bond has a frequency of vibration of 8....

*September 8, 2011*

**Chemistry**

I don't understand that process, since the answer for the meters is supposed to be 316m

*September 7, 2011*

**Chemistry**

An AM station broadcasts rock music at "950 on your radio dial" Units for AM frequencies are given in kilhertz(kHz). Find the wavelength of the station's radio waves in meters, nanometers, and angstroms.

*September 7, 2011*

**Chemisty**

Calculate the energy in radiation of wavelength 550 nm carried by 1) one photon 2) 1 mol of photons

*September 6, 2011*

**Chemisty**

Calculate the energy in radiation of wavelength 550 nm carried by 1) one photon 2) 1 mol of photons

*September 6, 2011*

**Math**

Like decimals, charts, fractions, estimating. At least that is what I had in 5th.

*September 4, 2011*

**SAT math**

If five distinct lines lie in a plane, then at most how many distinct points can lie on two or more of these lines? 6 7 8 9 10.

*August 19, 2011*

**algebra**

TGIF. Chris and Terry have been trying to live within their budget but miss going out to dinner on Friday nights. They decide not to spend any nickels or quarters they receive as change for a month and save these in a jar. At the end of the second week they have a total of 165...

*July 17, 2011*

**math**

Write the equation of the line satisfying the given condition. Parallel to y = (2/3)x +1 and passing through the point (0, -3). (Hint: Parallel lines have the same slope

*July 17, 2011*

**algebra**

Write the equation of the line satisfying the given condition. Perpendicular to y = 4x + 2 and passing through the point (0, -4) (Hint: Slopes of non-vertical perpendicular lines are negative reciprocal of each other.)

*July 17, 2011*

**algebra**

Solve the inequality algebraically. Graph your solution on a number line.

*July 17, 2011*

**math**

Suburban Population. The following charts show the populations for two suburbs from 1980 to 1990, where x = 0 correspond to 1980, x = 2 correspond to 1982, and so on. Year x Suburb 1 y Year x Suburb 2 y 0 12,690 0 23,112 2 12,071 2 23,893 4 13,463 4 24,674 6 13,867 6 25,455 8 ...

*July 17, 2011*

**mathh**

The average (arithmetic mean) of x and y is m, where m does not equal to 0. What is the average (arithmetic mean) of x, y, and z? a.)m b.)4/3m c.)3/2m d.)5/3m e.)2m

*July 10, 2011*

**math**

A flat stone is thrown horizontally across a frozen lake. If the stone decelerates at 2.5 meter per second squared, what is the coefficient of friction between the stone and the ice?take g equals 10 meter per second

*June 18, 2011*

**Science (Chemistry)**

The Average density of Earth is 5.52g/cm^3. What is its density in a. kg/m^3 b. lb/ft^3. Please help me set up these equations. Thank you!

*June 13, 2011*

**physics**

What is force of attraction between two students of mass 20kg,10meters apart?

*June 5, 2011*

**physics**

What is force of attraction between two students of mass 20kg,10meters apart?

*June 5, 2011*

**science**

i need 3 examples of supension. any suggestions?

*May 11, 2011*

**maths**

Oh sorry! Thanks

*May 8, 2011*

**maths**

The mass of a particular substance is known to grow exponentially at a rate of 0.5% per hour. Its initial mass was 25 grams and, after t hours, it weighed 31 grams. The equation modelling this growth is 25×1.005 t = 31. Use the method of ...

*May 8, 2011*

**chemistry**

Which of the following statements are true? Fusion reactions result in nuclei with higher Z. To keep a nuclear power plant going, a chain reaction must be maintained. Nuclear fusion produces no long-lived radioactive by-products. The Sun is a nuclear fusion reactor.

*April 14, 2011*

**Algebra 1**

What is 1/9+1/y=4/y

*April 5, 2011*

**physics **

A car is travelling at 42.4 km/h on a flat highway. The acceleration of gravity is 9.81 m/s^2. If the coefficient of friction between the road and the tires on a rainy day is 0.125 what is the minimum distance for the car to stop? Answer is metres

*April 2, 2011*

**maths**

find in implicit form, the general solution of the differential equation dy/dx = 2(e^x-e^-x)/y^2(e^x+e^-x)^4

*March 24, 2011*

**chemistry**

Why sodium oxide is a solid at room temperature whereas sulfur trioxide is a low boiling point liquid?

*March 12, 2011*

**Chemistry**

The boiling ponit of phophine is -85 oC, whilst of ammonia in the same group is -33.5 oC, how can we account for this difference in BP?

*March 12, 2011*

**chemistry**

sorry if that was confusing

*March 2, 2011*

**not really sure**

What is the mass of a mole of Sodium Carbonate?

*March 2, 2011*

**Life orientation**

Which two labour laws protect the employee against discrimination in the work place?

*February 21, 2011*

**Calculus**

Find the derivative of 4e^x+x^3

*February 10, 2011*

**Calculus**

Derivative of: (t^7+t^8-1)/t^9

*February 9, 2011*

**Chemistry**

FeSCN2+ -> Fe3+ + SCN- Solution is initially dark red. If some Ag+ is added to form AgSCN. what happens to position of equilibrium? what happens ot the color?

*February 8, 2011*

**Calculus**

Find the equation of the line tangent to the graph of f at (1,1) where f is given by f(x)=2x^3-2x^2+1

*February 8, 2011*

**chemistry**

8.What is the mass of 4.56 moles of sulfur dioxide? 9.What is the mass of 4.56 molecules of sulfur dioxide? 10.How many formula units are in 0.456 grams of Ca3(PO4)2? 11.How many moles are in 1.5 x 10 ^23 atoms of fluorine? 12.What is the mass of 2.80 x 10 ^23 molecules of CO2?

*February 6, 2011*

**chemistry**

1.How many atoms are in a sample of copper with a mass of 18.46 grams? 2.How many formula units are in a sample of salt with a mass of 67.69 grams? 3.How many molecules are in a sample of water with a mass of 44.99 grams? 4.What is the mass in grams of 0.250 moles Mg? 5.How ...

*February 6, 2011*

**chemistry**

1.How many atoms are in a sample of copper with a mass of 18.46 grams? 2.How many formula units are in a sample of salt with a mass of 67.69 grams? 3.How many molecules are in a sample of water with a mass of 44.99 grams? 4.What is the mass in grams of 0.250 moles Mg? 5.How ...

*February 6, 2011*

**Calculus**

The number of bacteria in a culture increases exponentially with a growth constant of .2 hour. How long will it take for the population to increase from 3000 to 25,000? Thank you for any help you can give and for your time!

*February 2, 2011*

**French**

Le garcon s'appelle Max. J'ai un frere et une soeur. Le francais c'est une langue tres facile. La voiture est rouge.

*February 2, 2011*

**Calculus**

Are the following differential equations separable or not? * y'= ye^(x+y) * y'= ye^(xy) * y'= y(xcos(y)) I am no good at these :[

*February 2, 2011*

**continuous compounding?**

$50,000 that was invested in 1970 was worth $134,100 in 1980. What annual interest rate did this investment earn in that 10 year period? Assume continous compounding.

*February 2, 2011*

**Chemistry**

The first step to solve this equation is to calculate the moles of the solvent and solute. The molar mass of H2O=18.016 g/mol The molar mass of C2H6O2=62 g/mol 50.5g of C2H6O2*(1mol/62g)=0.815 mol C2H6O2 50.5 g of H2O*(1mol/18.016g)=2.803 mol H2O. Now you need to find the mole...

*January 26, 2011*

**health records law**

Of the following types of information, which one has the strictest rules regarding the release of information? A. substance abuse B.mental illness C.genetic information D.Adoption information

*January 25, 2011*

**Geography**

This is the least mountainous country of Southern Europe. 1) Greece 2) Italy 3) Portugal 4) Spain in my book, it says all of them are mountainous. help?

*January 20, 2011*

**Junior Math**

Can you help me combine the expression into a single fraction? (t^2-1)/(t^2+7t+10) - (2t+4)/(t^2-t-6) and (3a-1)/(2a+6) - 7a/(a^2+7a+12) Thanks!

*January 19, 2011*

**physics**

a physics book is on top of a drafting table at 35 degree angle. Find the net external force acting on the book and determing wether the book move or remain at rest on this position. they give you: force of friction 11N, force normal 18N,force of gravity on the book 22N.

*January 16, 2011*

**pre algebra**

Mrs.brown mr.green and mr.white live in houses that are brown green and white none of these people have a house or car that is the same color as there last name . mrs . brown has a car that is the same color as mr. white's house . what is the color of mr.greens house

*January 13, 2011*

**Physics**

2 moles of ideal gas are in a cylinder container with cross-sectional area 1*10^-2 m^3. Cylinder is fitted with a light, movable piston that is open to atmosphere, where pressure is 10^-5 PA.A 50KG MASS PLACED ON PISTON KEEPS IT IN mechanical equilibrium when temperature is ...

*January 13, 2011*

**Chemistry**

How many moles of CO2 would be contained in a cylinder the size of a pop can (355 ml) at a temperature of 300K and 10 atm? How much would that weigh?

*December 6, 2010*

**Math**

a piggy bank contains $8.80 in quarters, dimes and nickles. there are two more than five times as many nickles as quarters, and four less than twice as many dimes as quarters. how may of each coin are there

*November 16, 2010*

**physics**

here is the rest coming out of the upper right corner of the rectangle is another tugboat. the angle between the boat and the side of the rectangle is 140 degrees. this boat is labelled Fb=5000N Fc is sticking out of the bottom of the boat

*November 15, 2010*

**physics**

it wont let me post the whole thing, but here is some. ok, the picture has a rectangle in the middle, with the long sides horizontal. coming out of the left side is a "tugboat" connected to a rope. it is labelled Fa=7500 N.

*November 15, 2010*

**physics**

oh... i feel stupid

*November 15, 2010*

**physics**

could someone tell me how to do this? 1. A diagram illustrating several tugboats applying forces to a barge is shown below. What is the magnitude and direction of force does tugboat C (Fc) need to apply to keep the tugboat from moving? C:\Documents and Settings\26536\My ...

*November 15, 2010*

** math**

for the function f,y=f(x) is inversely proportional to x, where x>0. If f (3)=6 what is the value of f(2)?

*November 8, 2010*

**Physics**

How did you figure out m2?

*October 26, 2010*

**Physics**

Two cars travel westward along a straight highway, one at a constant velocity of 85 km/hr, and the other at a constant velocity of 115 km/hr. a) Sketch the velocity vs. time graph for both cars and paste your sketch in the space below. b) Assuming both cars start at the same ...

*October 24, 2010*

**Physics**

An engineer is designing a runway for an airport. Several planes will use the runway and the engineer must design it so that it is long enough for the largest planes to become airborne before the runway ends. The largest plane accelerates at 3.30 m/s2 and has a takeoff speed ...

*October 23, 2010*

**Physics**

If a car starts from rest and travels for 5.0 seconds with a uniform acceleration of +1.5 m/s2. The driver then applies the brakes for 3.0 seconds, causing a uniform acceleration of - 2.1 m/s2. a) Sketch the velocity vs. time graph for the car and paste your sketch in the ...

*October 23, 2010*

**Physics**

Two students are on a balcony 29.4 m above the street. One student throws a ball vertically downward at 14.7 m/s. At the same instant, the other student throws a ball vertically upward at 29.4 m/s . The second ball just misses the balcony on the way down. a) Sketch the ...

*October 23, 2010*

**physics**

A small first aid kit is dropped by a rock climber who is descending at a constant velocity of - 1.3m/s. a) Sketch the velocity vs. time graph for both the climber and her first aid kit and paste your sketch in the space below. b) After 1.5 seconds, what is the velocity of ...

*October 23, 2010*

**Macroeconomics **

A banks total assets equal 1 billion. It's Liabilities equal 1 billion. Transaction deposits equal 500 million, loans equal 700 million and securities equal 250 million. A: If the banks only other liabilities are savings deposits, what is the value of these savings ...

*October 13, 2010*

**2nd grade**

thank u.

*October 5, 2010*

**Math**

31, 32, 33, 34, 35, 36, 37, 38, 39 what numbers add up to 10?

*October 5, 2010*

**Math**

What is the number? It is greater than 30 and less than 40. If you add the digits, the sum is 10.

*October 5, 2010*

**chemistry**

What is the total sample size (in grams)for a sample of ethanol (CH3CH2OH) which contains 3.39 grams of oxygen?

*September 22, 2010*

**3rd grade**

No, 3rd graders don't get algebra. 4th can get those really easy ones such as 2*?=32. 5th is more of rounding decimals and things like that. Algebra doesn't come in until like 7th grade.

*September 22, 2010*

**science**

what is the appearance of: Iron? Sulphur? A mixture of both when heated?

*August 3, 2010*

**Pharmacy math**

calculate the ordered medication for each of the following IV bags to achieve the ordered concentration Ordered: Add 30 mEq KCl per L of IV fluid. On hand: 360 mL IV solution. On hand is KCl 2 mEq / mL Add: ______mEq; ___ mL Ordered: Add 20 mEq KCl per L of IV fluid. On hand...

*July 11, 2010*

** math**

A theater group made appearances in two cities. The hotel charges before tax in the second city were lower than in the first. The tax on the hotel bill was in the first city and in the second. After the trip, the total tax paid on accommodation expenses was . How much was the ...

*June 26, 2010*

**chemistry**

so then the best answer is a like I suspected.. but you agree it would have been bluish and then turning yellow not so much greenish?

*May 10, 2010*

**chemistry**

what is observeed when carbon dioxide was bubbled into bromothymol blue? a. the color of the solution changed from greenish to yellow color. b. the solution turned cloudy c. the color of the solution changed from yellow to colorless d. a precipitate formed again I say the ...

*May 10, 2010*

**chemistry**

cloudy?? no bubbles??

*May 10, 2010*

**chemistry**

when I bubbled Alka selzer into limewater I believe all I saw was small bubbles form. is that correct and why? if not what should I have observed.

*May 10, 2010*

**chemistry**

yay i got that one right :)

*May 10, 2010*

**chemistry**

when you insert a glowing wooden toothpick into a oxygen-filled pipet what would you observe? a. nothing b. the glow of the toothpick went completely out c. heard a gentle pop d. the glow of the toothpick got brighter and may have reignited. again Im checking to see if I did ...

*May 10, 2010*

**chemistry**

why would my flame have looked bigger what do you think i was doing wrong?

*May 10, 2010*

**chemistry**

when you hold a hydrogen filled pipet bulb horizontally with its mouth about 1 cm from a falme while gently squeezing what would you observe? a. the flame goes out b. a gentle pop and the flame may have been blown out c. the flame got bigger d. nothing happened I think that ...

*May 10, 2010*

**venn diagram**

Let smokers =A. Gum chewers=B n(AuB)= n(A) + n(B) -n(AnB). 100 + 150 - 75 =250-75=175 neither =400-175=225

*May 10, 2010*

**CHEMISTRY**

The specific heat capacity (cp) of lead is 0.13 J/g °C. How much heat (in J) is required to raise the temperature of 15 grams of lead from 22 °C to 37 °C? a. 2.0 b. -0.13 c. 0.13 d. 29

*May 9, 2010*

**CHEMISTRY**

The specific heat capacity (cp) of lead is 0.13 J/g °C. How much heat (in J) is required to raise the temperature of 15 grams of lead from 22 °C to 37 °C? a. 2.0 b. -0.13 c. 0.13 d. 29

*May 9, 2010*

**CHEMISTRY**

The major component of vinegar is acetic acid CH3COOH. Which of the following reactions represents the balanced equation between acetic acid and sodium bicarbonate? a. CH3COOH(aq) + NaHCO3 a CH3COONa(aq) + CO2(g) + H2O(I) b. CH3COOH(aq) + 2 NaHCO3(aq) + 3/2 O2(g) a 4 CO2(g) + ...

*May 9, 2010*

**CHEMISTRY**

which one of the following reactions represents the balanced chemical equation for the formation of water from hydrogen gas and oxygen gas? a. 2H(g) + O(g) a H2O(I) b. H2(g) +o(g) a H2O(I) c. 2 H2(g) + O2(g) a 2 H2O(I) d. 2 H(g) + 1/2 O2(g) a H2O(I)

*May 9, 2010*

**chemistry**

Why is it necessary to wait until the filter paper containing a compound is completely dry before weighing it? and how would it effect the theoretical yield? HIgher?? lower??

*May 6, 2010*

**chemistry**

which reactant in the reaction of sodium carbonate and calcium chloride dihydrate is the limiting reactant if 1.00 gram of each reagent is used? a. sodium carbonate b. calcium chloride dihydrate

*May 6, 2010*

**chemistry**

when aqueous solutions of copper II nitrate and sodium phosphate are mixed, sodium nitrate and copper II phosphate are formed. In the balanced chemical equation what is the coefficient of sodium nitrate?

*May 6, 2010*

**7th grade**

Well im a korean and i lived there till 3years ago. but before i answer the quastion, i wanna ask you something do you mean monsoons here in USA or in korea just kinda confused you know

*April 28, 2010*

**Chemistry**

Is there a website that explains this please??

*April 27, 2010*

**Chemistry**

what happens when sodium chloride is added to boiling water and why?? Can someone please explain!

*April 27, 2010*

**biology**

I'll take that as a yes. Thanks for nothing! 😊

*April 22, 2010*

**biology**

Hey guys, I went looking and I think I found the answer: The gizzard churns the food and moves it to the intestine to be absorbed. Does that sound right?

*April 22, 2010*

**biology**

Help! I have this science worksheet due tomorrow and I don't know the answer to this question! Ah! Please! Someone please answer the question, I'll be waiting...

*April 22, 2010*

**Physics **

Suppose at a concert a singers voice is radio broadcast all the way around the world before reaching the radio you hold to your ear . How long does this take . __ seconds I don't understand thisss ! Help me !

*April 11, 2010*

**Physics **

Suppose at a concert a singers voice is radio broadcast all the way around the world before reaching the radio you hold to your ear . How long does this take . __ seconds I don't understand thisss ! Help me !

*April 11, 2010*

**Corporate Finance**

PROJECT RISK RETURN A High 15% B Average 12 C High 11 D Low 9 E Low 6 so the projects A, B, and D will maximize the shareholder wealth

*March 1, 2010*

**chemistry**

2. Bromine can be added to limonene to create a brominated compound. The balanced equation is shown below. When 613 mg of limonene and 3.5 mL of a 10% (v/v) solution of Br2 in dichloromethane (a solvent) are combined, 959 mg of the product is isolated. Calculate the percent ...

*February 23, 2010*

**Physics**

A 45 kg crate is placed on an inclined ramp. When the angle the ramp makes with the horizontal is increased to 29 degrees, the crate begins to slide downward. What is the coefficient of static friction between the crate and the ramp? At what angle does the crate begin to slide...

*February 22, 2010*