Thursday

September 29, 2016
Total # Posts: 1,782

**Math**

8 1/2 + 4 1/3 + 2 1/2 + 2 2/3

*September 11, 2011*

**chemistry**

50457600 seconds. Turn this into scientific notation.

*September 7, 2011*

**chemistry **

it is the rest of my question B. is this reaction exothermic or endothermic? C. what is the oxidizing agent in this reaction D. in corrosion reactions the oxidizing agent actually removes electrons from the oxidized substance . are electrons actually removed in combustion?explain

*September 1, 2011*

**chemistry **

oxygen will react with the metal copper it will also react with the nonmetallic compound butane (c4h10) which ofthese reactions is combustion reaction?explain your answer.

*September 1, 2011*

**CHEMistry**

To find the net mass of something do you subtract the average mass of an empty can from the average mass of cans of regular soda. So I can calculate the density of cola. net mass of cola divided by volume of cola. What does net mass mean?

*August 29, 2011*

**PLEASE HELP ME! CHEMISTRY**

I get.... (x)(59.9338) +(1-x)(58.9332) =(58.9901) 59.9338x+58.9332-58.9332x=58.9901 1.0006x=0.0560 x=0.0569 cobalt60 abundance=0.0569% cobalt59 abundance=0.9431% 0.0569/0.9431 X 1.8155g = .10953grams Is that right?? It looks like i did it wrong.

*August 29, 2011*

**chemistry**

one atmospheric compound is responsible(after it has dissolved in water)for both the general acidity of normal rainwater and the acidity of much soil. what is this compound?

*August 23, 2011*

**world cultures**

o i have to do this project about the 5 themes of geography. and we are supposed to research the 5 themese of london. but i dont know how to research that or what to do. so please help

*August 21, 2011*

**writing**

haha wow thank you so much, i could've thought of that

*August 10, 2011*

**writing**

does anyone know a timeline about john paul 2's life?

*August 10, 2011*

**science**

pls answer the above question

*August 5, 2011*

**geometry**

I found out the first part of which is x for the figure which was 115 degrees.They do give you the other measures of the angles which are 115,155,155,155.135,135,115.The second part of the problem say yo find the sum of the measures of the exterior angles,one at each vertex,...

*July 23, 2011*

**physics**

T = (2pir)/v with T being the period, r being the radius, and v being the speed. Don't forget that radius is half the diameter. So, v*4.6s = 2*pi*2.5m

*July 7, 2011*

**Chemistry **

How do you calculate the number of moles of NaOH to add to a liter of 1M NH4CL (pka of NH4+ = 9.25 ) to produce a solution buffering the pH at 8.75 ? thanks

*June 29, 2011*

**math**

8-2 |r| = -12 ???

*June 28, 2011*

**math**

ohhh alright i get it know. thanks for the help!

*June 27, 2011*

**math**

use a number line to find the sum of the numbers. 1. 3 and 5 2. -6 and 3 i don't get this

*June 27, 2011*

**Geometry**

I need help with counterexamples and all the questions are false. 1.If an angle measures 34 degrees ,then the angle is acute. 2.If the length of twwo segments are each 17 feet,then the segments are congruent. 3.If two angles 32 and 148 degrees ,then are supplementary. 4.If you...

*June 26, 2011*

**chemistry**

what is the total mass of LiBr required to make 500.0 grams of an aqueous solution of LiBr that has a concentration of 338 ppm?

*June 22, 2011*

**chemistry**

what is the total mass of LiBr required to make 500.0 grams of an aqueous solution of LiBr that has a concentration of 338 ppm?

*June 22, 2011*

**Algebra**

James has saved $50. He wants to buy a DVD player for $149 in about 5 months. To find out how much he should save each week he wrote 50+20x=149. Explain his equation.

*June 16, 2011*

**physics**

a mass (m=2.00kg) is traveling at an initial speed of 18.0m/s. find the force needed to bring the mass to rest in a distance of 45.0m----what equation to use??

*June 14, 2011*

**Chemistry**

carbon dioxide (CO2) is the gas mainly responsible for global warming (the greenhouse effect). the burning of fossil fuels is a major cause of the increased concentration of CO2 in the atmosphere. carbon dioxide is also the end product of metabolism. a general overall equation...

*June 13, 2011*

**physical science**

38239.25

*June 12, 2011*

**science**

i have to do balancing equation problems and i cant figure out this problem, help? i think you have to put numbers infront but i dont get it. _H2+_O2<==>_H2O (those 2's are subscripts)

*June 6, 2011*

**business**

The clues that could help you determine between expressions and equations are if it has simple arithmetic operations such as 3 + 5 x( (-2)^7 -3/2 then it’s an expression however if it is set up as P=Q which is equivalent with P-Q=0 it’s an equation The things to ...

*June 5, 2011*

**Biology**

What is in urine after in has been filtered thrigh the kidneys?

*May 25, 2011*

**computers**

2. An enterprise level company wishes to set up a network to support several hundred business users as well as manufacturing equipment in a new building. Describe what network device or devices you would recommend they purchase and explain why. Note, you are not required to ...

*May 24, 2011*

**Math**

12 is what percent of 48

*May 18, 2011*

**Poems**

Thank you so much for the help!! :)

*May 15, 2011*

**Poems**

I am writing a free verse poem and I need somr ideas. I was thinking about a doll who could speak but I'm not sure if that is good. Any ideas?_

*May 15, 2011*

**Chemistry**

A 1.00 L sample of a pure gas weighs 0.785 g and is at 733.4 torr and 29.2 degree celcius. a) what is the molar mass of the gas? b) if the volume of the temperature are kept constant while 0.400 g of the same gas are added to that already in the container, what will the new ...

*May 12, 2011*

**Chemistry**

A 0.1873 g sample of a pure, solid acid, H2X was dissolved in water and titrated with 0.1052 M NaOH solution. The balanced equation for the neutralization reaction occurring is H2X(aq) + 2NaOH(aq) ¨ Na2X(aq) + 2H2O(l) If the molar mass of H2X is 85.00 g/mol, ...

*May 11, 2011*

**english**

how do I punctuate this sentence ? What did the philosopher Aristotle mean when he said "To perceive is to suffer"? or is this correct?

*May 10, 2011*

**geometry**

Given that circle A has a radius of 52 and a radii AB and AC form an angle of 132 degrees, find the exact length of BC

*May 2, 2011*

**alegebra **

how to you simplify 5 sqrt 320 how do i start

*April 29, 2011*

**English**

Why are marginalized characters used in literature?

*April 28, 2011*

**Physics**

A movable piston having a mass of 7.26 kg and a cross-sectional area of 5.26 cm2 traps 0.250 moles of an ideal gas in a vertical cylinder. If the piston slides without friction in the cylinder, how much work will the gas do when its temperature is increased from 20.5oC to 286oC?

*April 28, 2011*

**Math**

Three drugs are being tested for use as the treatment of a certain disease. Let p 1 , p 2 , and p 3 represent the probabilities of success for the respective drugs.As three patients come in, each is given one of the drugs in a random order. After n = 10 “triples” ...

*April 27, 2011*

**Math(Probability) need help**

Three drugs are being tested for use as the treatment of a certain disease. Let p 1 , p 2 , and p 3 represent the probabilities of success for the respective drugs. As three patients come in, each is given one of the drugs in a random order. After n = 10 “triples” ...

*April 27, 2011*

**Math**

Three drugs are being tested for use as the treatment of a certain disease. Let p 1 , p 2 , and p 3 represent the probabilities of success for the respective drugs. As three patients come in, each is given one of the drugs in a random order. After n = 10 “triples” ...

*April 27, 2011*

**Statistics**

A survey claims that 9 out of 10 doctors recommend Aspirin for their patients who have children. To test this claim against an alternative that the actual proportion of doctors who would do this is less than the claimed, a random sample of 100 doctors was considered. In this ...

*April 26, 2011*

**physics - rotational motion**

A small car of mass, m, is release at height, h, on a steel track. the car rolls down the track and through the loop of radius, R. at the end of the rack, the car rolls off the track, which is positioned at height, H, above the floor. neglect friction and the small amount of ...

*April 22, 2011*

**chemistry (need some help)**

In a series of decays (hypothetical), the nuclide Ra-227 beomes Pb-203. How many alphas and how many betas are emitted in this series? Give two answers: first, give the number of alpha decays; then, the number of beta decays. I know that there are 6 alpha decays happening. I ...

*April 19, 2011*

**science**

How much water should be added to 55.0 mL of 0.201 M HCl to dilute the solution to 0.155 M?

*April 18, 2011*

**chemistry**

Lactic acid, C3H6O3, is found in sour milk. A solution containing 1.00g NaC3H5O3 in 100.0mL of 0.0500M C3H6O3 has a pH= 4.11. Calculate the Ka of lactic acid

*April 14, 2011*

**Math**

What is the value of this expression when x=-3?

*April 11, 2011*

**Math**

Factor the following.. x^2 +16x -144=0

*April 9, 2011*

**simple subject and predicate**

Many useful tools are made from metal.

*April 6, 2011*

**trig**

2 cosine squared pi over 8 minus 1 find exact value of given expression

*April 4, 2011*

**Chemistry**

Which of the following substances will oxidize Sn(s) to Sn^2+? a) Cu(s) b) Cl2(g) c)Cl-(g) d) Mg(s) e) Cu^2+(aq) f) Mg^2+(aq)

*April 4, 2011*

**Algebra 2**

The frequency of a radio wave is inversely proportional to the wavelength. If a wave 250 m long has a frequency of about 1200 kHz, what is the approximate length of a wave with a frequency of 800 kHz? A. 167 m B. 258 m C. 325 m D. 375 m

*March 28, 2011*

**Algebra 2**

If y is inversely proportional to x and y=12 when x=2, what is the value of x when y=3? A. 2 B. 3 C. 8 D. 12

*March 28, 2011*

**Geometry**

What is the area of a regular hexagon with a side length of 14ft?

*March 24, 2011*

**math/geometry**

wouldn't it be just 4:1 because 48/12=4. 12 is 1/4 of 48 hence.. 4:1

*March 24, 2011*

**Chemistry**

Yeah and I responded to that and you did not respond to that.

*March 22, 2011*

**Chemistry**

A stressed chemistry student is hyperventilating into a paper bag. The student stops to wipe his brow after a few breaths, and the bag is at 5.7 KPa and the temperature in the lecture hall is 24 °C. The bag is 0.75L full. The student then goes at it again, and completely ...

*March 22, 2011*

**Chemistry**

No I don't think so because after the student goes at it again it is filled to 1.2L and it can't be more than completely filled. I think I am probably supposed to use V1/T1=V2/T2 or P1V1/T1= P2V2/T2. I just do not know because I feel like I have two volumes.

*March 22, 2011*

**Chemistry**

A stressed chemistry student is hyperventilating into a paper bag. The student stops to wipe his brow after a few breaths, and the bag is at 5.7 KPa and the temperature in the lecture hall is 24 °C. The bag is 0.75L full. The student then goes at it again, and completely ...

*March 22, 2011*

**Chemistry**

Hi Dr. Bob, Thank you for the help! I took a few hours to think about something else and I was finally able to get the problems answered. I hope I did my calculations correctly. Thanks again!

*March 19, 2011*

**Chemistry**

I have two questions: 1. A sample of 10.7 g of CO reacts completely with O2 to form CO2. How many grams of CO2 will be formed? 2. Urea (NH2)2CO is prepared by reacting ammonia with carbon dioxide. The byproduct is water. 637.2 g of ammonia are reacted with 787.3 g of carbon ...

*March 19, 2011*

**Science**

because science has proven it by the heat of the equator found the earth

*March 16, 2011*

**physics**

if two cups of tea one at 80 degrees and one at 50 d are placed in a cold room what one would get to room temp first and why won't they fall to 0 d i think q1 is 50 d am i right thanks so much

*March 16, 2011*

**physics**

if two cups of tea one at 80 degrees and one at 50 d are placed in a cold room what one would get to room temp first and why won't they fall to 0 d i think q1 is 50 d am i right thanks so much

*March 16, 2011*

**Europe**

what are the 5 themes of geography in france and the answer for each?

*March 16, 2011*

**accounting**

When Collum Corporation was organized in January 2011, it immediately issued 10,000 shares of $60 par, 5 percent, cumulative preferred stock and 20,000 shares of $10 par common stock. The company's earnings history is as follows: 2011, net loss of $15,000; 2012, net income...

*March 13, 2011*

**Chemistry**

What is the standard enthalpy of reaction for the following reaction: H2 + 1/2 O2 --> H2O(g)

*March 11, 2011*

**Calculus**

Thank you, but is there an easier way to do this? This is grade 12 calculus and I dont think I can use newtons solution for my answer if I have never heard of it.

*March 9, 2011*

**Calculus**

I am supposed to find when there will be 40 berry bushes. I am given the function p(t)=(16t+50t^3)^1/3. P is the population of a certain type of bush in a conservation area and t is time in years. I know that i am supposed to make p(t) = 40, but i dont know how to solve for t...

*March 9, 2011*

**Spainish**

I need help coganting the verb ir.Please can some give me examples of how it is used in a sentence.

*March 7, 2011*

**Chemistry**

An unknown gas has a molecular weight of 30.07 g/mol. What is the density of the gas at STP?

*March 4, 2011*

**physics**

A 149-{\rm g} baseball is dropped from a tree 12.0 m above the ground. If it actually hits the ground with a speed of 7.50 m/s, what is the magnitude of the average force of air resistance exerted on it?

*February 28, 2011*

**3rd grade math**

carl put his coins on pages in a book. He has 22 coins. He can put 4 coins on each page. How many coins would Carl put on the 6th page? Explain?

*February 28, 2011*

**Calculus**

an open top box is to be made by cutting congruent squares of side length x from the corners of a 12 by 15 inch sheet of tin and bending up the sides. how large should the squares be? what is the resulting maximum value?

*February 28, 2011*

**Math**

x is a number between 3 and 50. How many vales of x is radical x / 13 a rational number?

*February 26, 2011*

**Algebra:Properties**

3(f+4)+2f Rewrite this expression without parentheses

*February 24, 2011*

**Algebra 2 **

sorry the fist set of numbers is the minor and the second set is the major

*February 24, 2011*

**Algebra 2 **

write an equation in standard form for the ellipse with endpoints of the major axis (-1,4) and (1,6)and endpoints of the major axisi at (-4,1) and (6,1) i have no idea how to start this

*February 24, 2011*

**Physics**

131,250

*February 23, 2011*

**7th grade math**

The volume of a cube is 343 mm2. What is the length of one side of the cube?

*February 23, 2011*

**Physics**

A person is riding a bicycle, the wheels of a bicycle have an angular velocity of +18.5 rad/s. Then, the brakes are applied. In coming to rest, each wheel makes an angular displacement of +14.5 revolutions. (a) How much time does it take for the bike to come to rest? 1 s (b) ...

*February 22, 2011*

**Physics**

The lead female character in the movie Diamonds Are Forever is standing at the edge of an offshore oil rig. As she fires a gun, she is driven back over the edge and into the sea. Suppose the mass of a bullet is 0.005 kg, and its velocity is +730 m/s. Her mass (including the ...

*February 22, 2011*

**Physics**

Car 1 has a mass of m1 = 65 multiplied by 103 kg and moves at a velocity of v01 = +0.95 m/s. Car 2, with a mass of m2 = 92 multiplied by 103 kg and a velocity of v02 = +1.1 m/s, overtakes car 1 and couples to it. Neglect the effects of friction in your answer. (a) Determine ...

*February 22, 2011*

**Physics**

A car (mass = 1180 kg) is traveling at 36 m/s when it collides head-on with a sport utility vehicle (mass = 2380 kg) traveling in the opposite direction. In the collision, the two vehicles come to a halt. At what speed was the sport utility vehicle traveling?

*February 22, 2011*

**Physics**

A projectile (mass = 0.10 kg) is fired at and embeds itself in a target (mass = 2.11 kg). The target (with the projectile in it) flies off after being struck. What percentage of the projectile's incident kinetic energy does the target (with the projectile in it) carry off ...

*February 22, 2011*

**Physics**

The work required to stretch a certain spring from an elongation of 4.73 cm to an elongation of 5.73 cm is 31.7 J. (a) Is the work required to increase the elongation of the spring from 5.73 cm to 6.73 cm greater than, less than, or equal to 31.7 J? (b) Verify your answer to ...

*February 22, 2011*

**Algebra**

I'm factoring special cases and i cant figure this problem out: 45t^2-72t+24 please help

*February 17, 2011*

**Chemistry**

but do you have to do something special since its gauge?

*February 12, 2011*

**Chemistry**

the air in a steel belted tire is at a gauge pressure of 29.8 psi at a temperature of 20 degrees celsius. After the tire is driven out fast on a hot road, the temperature in the tire is 48 degrees celsius. What is the tires new gauge pressure. Can someone please explain this ...

*February 12, 2011*

**Science**

thanku!

*February 12, 2011*

**Science**

Helium gas in a balloon occupies 2.5 L at 300.0 K. The balloon is dipped into liquid nitrogen that is at a temperature of 80.0 k. What will the volume of the helium in the balloon at the lower temperature be? I got a weird answer like .66667 and i used charles law

*February 12, 2011*

**Math**

What is the ratio comparing the length in a drawing to the corresponding length of the object is called?

*February 9, 2011*

**Math**

On a die, the top and bottom numbers always add up to 7. What are the three pairs that each add up to?

*February 9, 2011*

**business math revised**

Bob makes his first $800 deposit into an IRA earning 7% compounded annually on the day he turns 27 and his last $800 deposit on the day he turns 35. (9 equal deposits in all.) With no additional deposits, the money in the IRA continues to earn 7% interest compounded annually ...

*February 9, 2011*

**business math**

Bob makes his first deposit into an IRA earning % compounded annually on the day he turns 27 and his last deposit on the day he turns 35. (9 equal deposits in all.) With no additional deposits, the money in the IRA continues to earn % interest compounded annually until Bob ...

*February 9, 2011*

**math**

A fireman stood in the middle of a step ladder. He climbed down 4 steps and continued his work. He went down 8 more then back up 9 to the top. How many steps were on the ladder?

*February 7, 2011*

**spanish**

¿Cuál es la forma correcta del imperativo para tú? ¡_____ aquí! (venir) ¿Cuál es la forma correcta del verbo para el imperativo tú? ¡______ a las siete! (salir) ¿Cuál es el imperativo para la forma t&...

*February 7, 2011*

**Physics**

An alpha particle and an antiproton are released from rest a great distance apart. They are oppositely charged so each accelerates toward the other. What are the speeds of the two particles when they are 2.5 nm apart? alpha particle has a charge of +2e and is four times as ...

*February 6, 2011*

**Physics**

A 0.7 um-diameter droplet of oil, having a charge of +e, is suspended in midair between two horizontal plates of a parallel-plate capacitor. The upward electric force on the droplet is exactly balanced by the downward force of gravity. The oil has a density of 860 (kg/m^3), ...

*February 6, 2011*

**Physics**

A +3.0 nC charge is at x=0 cm and a -1.0 nC charge is at x=4 cm. At what point or points on the x-axis is the electric potential zero?

*February 3, 2011*