# Posts by sarah

Total # Posts: 5,763

**chemistry**

describe what happen when a piece of wet red litmus paper is passed through a hydrogen gas.

*January 17, 2016*

**chemistry**

describe what happen when a piece of wet red litmus paper is passed through a hydrogen gas.

*January 17, 2016*

**Chemistry**

At pH 9 what will the ratio of ammonium to ammonia be? The pKa of ammonium is 9.24?

*January 17, 2016*

**Physics**

Hi Damon Can you please explain how you got 19 ? and why is it being divided by 1.7 ? Thanks! Sarah

*January 17, 2016*

**Physics**

The diameter of our disk-shaped galaxy, the Milky Way, is about 1.7E+5 light-years (ly). The distance to the Andromeda galaxy, which is the spiral galaxy nearest to the Milky Way, is about 1.9E+6 ly. If a scale model represents the Milky Way and Andromeda galaxies as dinner ...

*January 17, 2016*

**Algebra/math**

A teacher is showing her class how to fold a square piece of paper to create a paper cup. One of the steps is shown below. According to the measurements, what is the length of x, in inches?

*January 16, 2016*

**Math**

A cookie recipe calls for 2/3 of a cup of flour and makes half a dozen cookies. How many cookies can you make if you have 9 cups of flour and want to use it all? I came up with an answer of 81 cookies by using a proportion. 2/3 over 6 (because half a dozen cookies is 6 cookies...

*January 15, 2016*

**Math**

The record for the fastest speed on a bicycle is 133 kilometers per hour. How long would it take a person traveling at this speed to travel 365.75 kilometers

*January 15, 2016*

**Chemistry**

The concentration of barium ions in any solution can also be determined via gravimetric analysis. An impure sample of barium nitrate with a mass of 1.234 g, is completely dissolved in water and the resulting solution is reacted with an excess of aqueous sodium sulfate. A ...

*January 13, 2016*

**Chemistry**

The concentration of barium ions in any solution can also be determined via gravimetric analysis. An impure sample of barium nitrate with a mass of 1.234 g, is completely dissolved in water and the resulting solution is reacted with an excess of aqueous sodium sulfate. A ...

*January 13, 2016*

**physics**

Assume the truck is going at v0 = 25 m/s, and you're 20 m behind the truck. You decide to accelerate at a = 1.0 m/s2 to pass the truck. To pass safely, you also want to pass the truck by 20 m before moving back to the lane. Part A ) Estimate the time interval needed to ...

*January 13, 2016*

**Physics**

Thank you so much!!!

*January 13, 2016*

**Physics**

what would I solve for when I do the conservation of momentum at the bottom of the block with the bullet?

*January 13, 2016*

**Physics**

A 0.15kg bullet is fired into a 1.85kg block that is hanging from a 45cm string. What minimum initial bullet speed is required if the bullet and block are to make one complete revolution? Please show all work. I need this question answered as soon as possible!

*January 13, 2016*

**physics**

A ball is thrown up onto a roof, landing 4 sec later at height of 20m above the release level. The balls path just before landing is angled at 60 degree with the roof. a) find the horizontal distance d it travels. b) what is the magnitude of the balls initial velocity? c) what...

*January 12, 2016*

**Math**

describe a situation where a trend line would be useful

*January 12, 2016*

**math help please**

48/3 = 16 2/3= 16x2= 32 she sold 32 muffins

*January 12, 2016*

**Math**

log2(-3sinx)=2log2(cosx)+1 solve for x

*January 12, 2016*

**Chemistry**

Compound X contains only carbon, hydrogen, nitrogen, and chlorine. When 1.00 g of X is dissolved in water and allowed to react with excess silver nitrate, AgNO3, all the chlorine in X reacts and 1.95 g of solid AgCl is formed. When 1.00 g of X undergoes complete combustion, 0....

*January 6, 2016*

**math**

Roma spent 30% of the money she bought to the mall..If she spent 450.00 only,how much did she have with her when she went to the mall?

*January 6, 2016*

**math**

after spending 80% of her money Lei has P100.00 left. How much was her money before

*January 5, 2016*

**science**

Suppose the height of the net is 0.800 m , and the court's border is 11.2 m from the bottom of the net. Use g =10 m/s2 and find the maximum speed of the horizontally moving ball clearing the net..

*December 16, 2015*

**Math**

A contractor buys 14 yd of nylon carpet and 20 yd of wool carpet for $1738. A second purchase, at the same prices, includes 16 yd of nylon carpet and 25 yd of wool carpet for $2102. Find the cost per yard of the wool carpet.

*December 13, 2015*

**pobability**

Suppose that 16% of the CD's that are distributed are defective. If you choose 5 CD's randomly, what is the probability that at least 1 of them is defective?

*December 11, 2015*

**Math**

How do integrate this with respect to x? integral of ((x^y)/y!)e^(-2x) from 0 to infinity The e is an exponential. The answer is supposed to be (1/2)^(y+1) but I don't know the steps to getting it.

*December 10, 2015*

**math**

Measuring number of surface of the rectangle is 128.If we reduce the length of 4 times, then the number is 96cm2.What is the perimeter?

*December 10, 2015*

**geometry**

c//d,<7 and< are= corresponding angles

*December 9, 2015*

**Chemistry**

Nevermind - I think I see what I did wrong. I was using 25 mL as my volume for hydrogen peroxide, when I should have been using 20 mL since that was the volume being added. Though I don't necessarily understand how that's the volume that needs to be used.

*December 9, 2015*

**Chemistry**

a 5.000ml aqueous sample containing hydrogen peroxide as diluted to 25ml and analyzed by titration with permanganate. 2MnO4- + 5H2O + 6H+ --> 5O2 + 2Mn^2+ + 8H2O The sample required 42.8 mL of 0.0175 M permangante to reach the end point. What is the concentration of H2O2 in...

*December 9, 2015*

**geography**

describe the impact the french and Indian war had on Florida?

*December 9, 2015*

**Chemistry**

Is it true that the higher the boing point, the higher the vapor pressure?

*December 8, 2015*

**Chemistry (I tried to do more)**

I think the order of decreasing vapor pressure is Acetamide, Acetic Acid, Propanal, and Isobutane. The trend is the higher the boiling point, the lower the vapor pressure. Is this right? If not, please explain.

*December 8, 2015*

**Chemistry**

Rank the following in order of decreasing vapor pressure, and briefly explain the observed trend in vapor pressure: Acetic Acid Isobutane Acetamide Propanal

*December 8, 2015*

**Chemistry**

Would copper (II) phosphate be nonpolar?

*December 7, 2015*

**Math**

The distance a bicycle travels with each turn of its wheels is about 3 1/7 times the tire diameter. The tires on Mike's bicycle have a diameter of 24 1/2 inches. How far does it travel with each turn of the wheels?

*December 7, 2015*

**Chemistry**

How can you tell if a compound is polar or nonpolar? Is it just by lewis structures? what would copper (II) phosphate be?

*December 7, 2015*

**Chemistry**

How do you determine it then?

*December 7, 2015*

**Chemistry**

When given different elements and asked for the highest boiling point, do you figure out the molar mass and pick the highest one as the highest boiling point?

*December 7, 2015*

**Math**

6x=24

*December 6, 2015*

**Math**

That polynomial can't be factored. Double check that you copied the equation correctly, then check out mathportal dot org.

*December 4, 2015*

**Social Studies**

Describe the role of shariah in Islam. What types of laws would one expect to find within Islamic governments, and how are they enforced? This was one of my questions on my homework, and I can't figure out a solid answer to it. Thank you!

*December 2, 2015*

**physics**

A 0.014 kg bullet is fired straight up at a falling wooden block that has a mass of 4.0 kg. The bullet has a speed of 700 m/s when it strikes the block. The block originally was dropped from rest from the top of a building and had been falling for a time t when the collision ...

*November 30, 2015*

**phyics**

Cheryl is riding on the edge of a merry-go-round, 2m from the center, which is rotating with an increasing angular speed. Cheryl’s tangential acceleration is 3.0m/s2. At the instant that Cheryl’s linear speed is 4.0m/s, what is Cheryl’s total acceleration? ...

*November 29, 2015*

**Chemistry**

The intreval volume of a clorimeter was1.12L. A sample of gas of 1.863g of nonae was added, and the closed calorimeter then had added oxygen until the pressure was 10.0atm na dht etemp was 23.1 C.Write the full balanced equation of the combustion of the nonae in the ...

*November 28, 2015*

**Chemistry**

Automotive airbags inflate when sodium azide, NaN3, rapidly decomposes to its constituent elements according to the chemical equation, 2 NaN3 -> 2 Na + 3 N2. How many grams of nitrogen are produced when 1000 milligrams of sodium azide decomposes?

*November 25, 2015*

**differential equations**

Nevermind, I got the answer.

*November 25, 2015*

**differential equations**

Convert x''+ sin(x) = 0 into a first order system of equations. (x'' refers to the second derivative of x). I tried: y1 = sin(x) y2 = x' {y1' = cosx {y2' = -sinx Not sure if I did it right.

*November 25, 2015*

**Algebra**

If you know all the answers please help me. I need help!

*November 24, 2015*

**Algebra**

1. determine whether the equation represents a direct variation , if it does find the constant of the vartion 2y=5x+1

*November 24, 2015*

**Phyics**

The foci of the elliptical path for an Earth satellite are __________. A) one at Earth's center and the other elsewhere B) one atop the other at Earth's center C) both inside Earth D) both outside Earth

*November 21, 2015*

**geometry**

given: -n+6=8n+6n prove:n=0

*November 18, 2015*

**Chemistry**

ok I set up the first one right, and got P=.998 atm The after composition makes sense and I got P = 20.0 atm Are these correct?

*November 18, 2015*

**Chemistry**

Calculate the pressure of 4.80g of ozone, O3, in a 2.45 L flask at 25 degrees C. Assume that the ozone completely decomposes to the molecular oxygen. 2O3(g) --> 3O2(g) Calculate the pressure inside the flask once the reaction is complete.

*November 18, 2015*

**Chemistry (Check)**

correct

*November 18, 2015*

**Chemistry (Check)**

What is the volume of the gas in a balloon at -195 degrees C if the balloon has been filled to a volume of 5.0L at 25 degrees C? Vf = 1.3L

*November 18, 2015*

**Chemistry**

Is it just .8252 kg/cm^3? because multiply 1000cm^3 / 1000kg

*November 18, 2015*

**Chemistry**

Calculate the density of methane gas, CH4, in kilograms per cubic meter at 25 degrees C and 956 mmHg. I got .8252 g/L but am getting confused with the converting units.

*November 18, 2015*

**Chemistry**

Calculate the pressure in an evacuated 250mL container at 0 degrees C when the O2 in 1.00 cm^3 of liquid oxygen evaporates. Liquid oxygen has a density of 1.118 g/cm^3.

*November 17, 2015*

**Science**

Nonmetals are often brittle

*November 17, 2015*

**Biology**

to produce a substance

*November 17, 2015*

**Business**

My apologies. It is the Harvard Business Review, not the Harvard Business Journal.

*November 17, 2015*

**Business**

I have to write a two page paper about a journal article. The article is "Beware the Next Big Thing" published in the Harvard Business Journal, 2014. In the essay I have to include: a. methodology b. objectives c. summary of research results d. managerial ...

*November 17, 2015*

**Math**

It is not a function because there are multiple y-values paired with a single x-value

*November 17, 2015*

**physics**

A cross-country skier who weighs 600 N has chosen ski wax that provides ฯ=0.03. What is the minimum amount of horizontal force,perhaps from a tailwind,that would keep the skier coasting at constant speed across level snow?

*November 16, 2015*

**math**

The track team plans to sprint 20 miles this school year. The runners will sprint 1/4 mile each day.How many days will it take them to sprint 20 miles?

*November 15, 2015*

**Chemistry (Edit)**

The CH3 in a is supposed to be under the second C in the compound.

*November 13, 2015*

**Chemistry**

Isomers are compounds that have the same number and kinds of atoms but have a different arrangement of the atoms. The enthalpies of atom combination for several pairs of gaseos isomers are given here. For each pair, decide which has the strongest bonds. a. CH3CH2CH2OH -4391....

*November 13, 2015*

**math help one question**

Standard form

*November 12, 2015*

**Math**

Standard form

*November 12, 2015*

**Chemistry**

Nitrogen and oxygen can react directly with one anotheer to produce nitrogen dioxide according to N2(g) + 2O2(g) --> 2NO2(g) The reaction may also be imagined to take place by first producing nitrogen oxide N2(g) + O2(g) --> 2NO(g) which then produces NO2 2NO(g) + O2(g...

*November 12, 2015*

**Math**

31,250 with prime factorization = 2x5^6

*November 12, 2015*

**Chemistry**

Oxyacetylene torches are fueled by the combustion of acetylene, C2H2. 2C2H2(g) + 5O2(g) --> 4 CO2(g) + 2H2O(g) If the enthalpy change for the reaction is -2511.14 kJ/molrxn, how much heat can be produced by the reaction of a. 2mol of C2H2? b. 1 mol of C2H2? c. .500 mol of ...

*November 12, 2015*

**Social Studies (please help)**

It is around the 500 to 600 CE

*November 12, 2015*

**Social Studies (please help)**

In what ways were diverse people from the Arabian Peninsula through the Middle East, North Africa, and into Spain united? What held them together and unified them, and how was this done?

*November 12, 2015*

**Chemistry**

Why are the two words "alkaline" and "earth" used to name the group 2 metals?

*November 11, 2015*

**Chemistry**

Which of the following nitrogen-containing compounds would supply the most nitrogen per gram of fertilizer? a. iron azide, Fe(N3)2, MW = 140 g/mol b. sodium azide, NaN3, MW = 65 g/mol c. potassium nitrite, KNO2, MW = 85.1 g/mol d. potassium azide, KN3, MW = 81.1 g/mol e. There...

*November 9, 2015*

**Physics**

2. Consider the ball example in the introduction when a ball is dropped from 3 meters. After the ball bounces, it raises to a height of 2 meters. The mass of the ball is 0.5 kg a. What is the speed of the ball right before the bounce? b. How much energy was converted into heat...

*November 5, 2015*

**Chemistry**

Describe how you would prepare 500 mL of a 0.10 M solution of HCl from a 12.0 M solution of HCl.

*November 3, 2015*

**Chemistry.**

Mg+2HCl--->MgCl2+H2 Using the balanced equation, how many moles of H2 will you make if you start with .00082 moles of Mg solid? How many grams of H2 is that?

*November 3, 2015*

**Science**

252g

*November 2, 2015*

**civics**

HELP ME PLEAASSEEE!!!!!!!

*November 2, 2015*

**civics**

What motivated the Founding fathers to include the phrase "to form a more perfect union" in the preamble of the U.S Constitution?

*November 2, 2015*

**civics**

I think its B

*November 2, 2015*

**Physics**

A curling stone with a mass of 18 kg slides 38m across a sheet of ice in 8.0 s before it stops because of friction. What is the co¨efficient of kinetic friction between the ice and the stone? (Note: you will need to calculate the acceleration of the stone first.) I solved ...

*October 29, 2015*

**Physics**

An object initially at rest experiences an acceleration of 9.8 m/s^2. How much time will it take to achieve a velocity of 58 m/s?

*October 28, 2015*

**Chemistry! HELP**

A chemistry student used the symbol "sx" to represent an s orbital that lies along the x-axis. Is this reasonable. Justify your answer.

*October 28, 2015*

**Chemistry! HELP**

What information about an electron in an atom is given by the following quantum numbers? 2px+1/2 Answer? (idk if this is right) : An electron located in the p orbital in the 2nd main enrgy level would be said to be located in the 2p sublevel.

*October 28, 2015*

**physics**

A 214-kg crate rests on a surface that is inclined above the horizontal at an angle of 19.4°. A horizontal force (magnitude = 541 N and parallel to the ground, not the incline) is required to start the crate moving down the incline. What is the coefficient of static ...

*October 28, 2015*

**Reading**

Did you find the answer to the question yet?

*October 23, 2015*

**Science**

If you guys are still looking for answers if you go to part on of the question there is a link that you use to find the answer.I hope this helped :)

*October 23, 2015*

**Science**

FYI I am not plagiarizing because all the credit is given to the people who made it |-/

*October 23, 2015*

**Science**

If you guys are still looking for answers if you go to part 1 of the question there is a link that you use to find the answer.I hope this helped :) Because collisions between large planetesimals release a lot of heat, the Earth and other planets would have been molten. (Brian ...

*October 23, 2015*

**Math**

Look at the orange mama laid

*October 21, 2015*

**Pre-calculus**

Thanks, Ms.Sue! You are amazing!

*October 19, 2015*

**Pre-calculus**

I have (x,y,z)=(-5a-15,-a-5,a)

*October 19, 2015*

**Pre-calculus**

Solve the system of linear equations and check any solutions algebraically. (If there is no solution, enter NO SOLUTION. If the system is dependent, express x, y, and z in terms of the parameter a.) x-3y+2z=21 5x-13y+12z=81 I have an answer but i'm not sure if it's ...

*October 19, 2015*

**physics**

The drawing shows four point charges. The value of q is 1.4 μC, and the distance d is 0.86 m. Find the total potential at the location P. Assume that the potential of a point charge is zero at infinity

*October 16, 2015*

**English**

I'm just looking for some ideas for an essay on a Tale of Two Cities.... it can be anything related to the book... and I'm not asking you to do my schoolwork for me... I can develop the thesis and points but I just need some ideas... this is for a 4u course and I ...

*October 14, 2015*

**Chemistry**

doesnt the concentration come into play some how?

*October 12, 2015*