# Posts by Lauren

Total # Posts: 1,828

**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 don't 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 don't know how to solve ...

*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*

**Physics**

A bicyclist is coasting straight down a hill at a constant speed. The mass of the rider and bicycle is 85.0 kg, and the hill is inclined at 19.0° with respect to the horizontal. Air resistance opposes the motion of the cyclist. Later, the bicyclist climbs the same hill at ...

*February 3, 2011*

**Physics**

A skier is pulled up a slope at a constant velocity by a tow bar. The slope is inclined at 24.0° with respect to the horizontal. The force applied to the skier by the tow bar is parallel to the slope. The skier's mass is 60.0 kg, and the coefficient of kinetic friction...

*February 3, 2011*

**Physics**

In the drawing, the weight of the block on the table is 430 N and that of the hanging block is 165 N. Ignore all frictional effects, and assuming the pulley to be massless. (a) Find the acceleration of the two blocks. (b) Find the tension in the cord.

*February 3, 2011*

**physics**

If you have swam one lap in a swimming pool, that means you have swam from one end to the other and back. In 3 h, a swimmer makes exactly 30 laps in a swimming pool that is 30 m long. Determine the distance the swimmer traveled, the total displacement of the swimmer, the ...

*February 1, 2011*

**physics**

A roofing tile falls from rest off the roof of a building. An observer from across the street notices that it takes 0.48 s for the tile to pass between two windowsills that are 3.0 m apart. How far is the sill of the upper window from the roof of the building?

*January 31, 2011*

**Research and Statistics**

I want to ensure I've done this problem correctly. Thanks! 3. In one elementary school, 200 students are tested on the subject of Math and English. The table below shows the mean and standard deviation for each subject. Mean SD Math 67 9.58 English 78 12.45 One student&#...

*January 31, 2011*

**7th grade math**

i need help!!!!!!!! A=44 in.2, b1=13 in., b2=9 in.,h=?

*January 26, 2011*

**Chemistry**

A package of aluminum foil covers 75.0 ft^2 and weighs 12 oz. Aluminum has a density of 2.70 g/mL. What is the thickness of the foil in millimeters? (1 in = 2.54 cm, 1 oz = 28.4 g, 1 mL = 1 cm^3)

*January 25, 2011*

**Physics**

Three blocks rest on a frictionless, horizontal table (see figure below), with m1 = 8 kg and m3 = 20 kg. A horizontal force F = 101 N is applied to block 1, and the acceleration of all three blocks is found to be 3.5 m/s2. Find m2. What is the normal force between blocks 2 and 3?

*January 25, 2011*

**Physics**

Consider two masses m1 and m2 connected by a thin string. Assume the following values: m1 = 4.51 kg and m2 = 1.00 kg. Ignore friction and mass of the string.

*January 25, 2011*

**precalc**

Is sine an even or odd function?

*January 21, 2011*

**chemistry**

322.5

*January 21, 2011*

**trig**

the question is: given sec x = 4, tan x < 0, find sin(2x), cos(2x)and tan (2x)

*January 19, 2011*

**calculus**

Put the function P=15(1.1)^t in the form Pe^kt

*January 17, 2011*

**physics**

An animal-rescue plane due east at 50 meters per second drops a bale of hay from an altitude of 62 meters. The acceleration due to gravity is 9.81 meters per second squared. If the bale of hay weighs 191 newtons what is the momentum of the bale the moment it strikes the ground...

*January 17, 2011*

**german**

im in year 9 and i'm suppose to know lods in german but all i can remeber is guten tag and ich habe.... heeelpppppppppppp!!!!

*January 16, 2011*

**HISTORY**

That's not at all what I meant. I wanted someone to NOT write me an essay, but to answer my question. Don't even write me a paragraph. Just answer my question, please. Then I will post my essay on here, too.

*January 16, 2011*

**HISTORY**

Write a short paragraph that traces the rise of Japan from an isolated society to a major industrial and imperial power. I have to write an essay, so if you can write me a short paragraph that answers and summarizes my question, then I can write my essay. Thank you everyone at...

*January 16, 2011*

**Chemistry**

1. 98.9?

*January 16, 2011*

**stats help!**

What 2 numbers is the emperical rule of 95% between if the P of no shows is .10 and the average party size is 10

*January 13, 2011*

**algebra**

X(squared)+8X+2

*January 11, 2011*

**Math**

What number has 6 in tenths place,4 in the ones place,5 in the hundredths place,and 9 in the tens place?help me!

*January 10, 2011*

**math help!!!!**

Boo boo goo goo ha ha

*January 10, 2011*

**math**

Boo boo doo doo ha ha

*January 10, 2011*

**Algebra 1**

solve f(x)=3x+2 for x.

*January 9, 2011*

**english can someone check my answers**

Sonny and _me___ have been inducted into the National Honor Society I Me The guide showed the other tourists and __them____ where in the palace the Treaty of Versailles had been signed. They Them The experimental vaccine against the malaria parasites attacks them_____ at the ...

*January 8, 2011*

**Math**

Okay I have a scatterplot, so I have points on the graph. I need to use these points (without using regression on my TI-83) to discover a cubic function that would fit the data (as a sort of trend line). How do I go about this? I looked up the graphing form of the cubic ...

*January 6, 2011*

**Algebra 1**

How do I simplify 5(-c+3a)-c(2c+1)? Show the work not just the answer so I actually get how to do it please.

*January 2, 2011*

**Algebra 1**

-y<36 What is y?

*December 16, 2010*

**Algebra 1**

5n-8 is < or = to 2n+10 What is n?

*December 16, 2010*

**Algebra 1**

-p/-7>-9 What is p? For solving inequalities.

*December 16, 2010*

**Algebra 1**

Let x be an integer. What is the product of twice the integer added to three times the next consecutive integer?

*December 13, 2010*

**english**

Which of the following is NOT a benefit that the narrator claims from his "modest proposal"? Question 9 answers A. national and international recognition for their efforts B. a sense of value and pride for poor people C. increase in profit and disposable income for ...

*December 10, 2010*

**math**

20 and 20 10 and 6

*December 9, 2010*

**english**

what are some facts about satire,lampoon,an d parody?

*December 9, 2010*

**spanish**

I am preparing for my oral exam (spanish 1) and i wrote all this down, can any one check my grammar, conjugations and add-on if necessary And also would this last me 3 minutes or should i write more to each question?? Tema 4 (un país hispanohablante) ¿Cuál...

*December 7, 2010*

**spanish**

I am preparing for my oral exam (spanish 1) and i wrote all this down, can any one check my grammar, conjugations and add-on if necessary And also would this last me 3 minutes or should i write more to each question?? Theme 3 (Chicago) ¿Cómo es Chicago? el clima...

*December 7, 2010*

**spanish**

I am preparing for my oral exam (spanish 1) and i wrote all this down, can any one check my grammar, conjugations and add-on if necessary And also would this last me 3 minutes or should i write more to each question?? Theme 2 (el tiempo libre) ¿Cuáles son tus ...

*December 7, 2010*

**spanish**

I am preparing for my oral exam (spanish 1) and i wrote all this down, can any one check my grammar, conjugations and add-on if necessary And also would this last me 3 minutes or should i write more to each question?? Theme 1 (Las vacaciones) ¿Adónde quieres ir ...

*December 6, 2010*

**Trigonometry**

The Chrysler Building casts a shadow approximately 130 feet long on the street when the Sun's rays form an 82.9 angle with the Earth. Approximately how tall is the building? Round you answer to four decimal places.

*November 28, 2010*

**Chemistry**

if metal A is placed in an ionic solution containing metal B ions and no reaction occurs, then metal B is most likely: A.) a halogen B.) higher on the activity series C.) not on the activity series D.) a catalyst

*November 28, 2010*

**Chemistry**

Calculate K at 25°C for the reactions given below. (a) Zn(s) + 2Ag+(aq) Zn2+(aq) + 2Ag(s) (b) 2H2O2 2 H2O + O2 Given: H2O2 + 2 H+ + 2e- 2 H2O ° = 1.78 V O2 + 2 H+ + 2e- H2O2 ° = 0.68 V

*November 23, 2010*

**Calculus**

the integral from 0 to pi/2 of sin^5(x)cos^18(x)

*November 23, 2010*

**Calculus**

the integral of sin^3xcos^2x my answer is -(1/2)(cosx)^2+(1/4)(cosx)^4+c but this is incorrect, please help.

*November 23, 2010*

**Chemistry**

Calculate K at 25°C for the reactions given below. (a) Zn(s) + 2Ag+(aq) Zn2+(aq) + 2Ag(s) (b) 2H2O2 2 H2O + O2 Given: H2O2 + 2 H+ + 2e- 2 H2O ° = 1.78 V O2 + 2 H+ + 2e- H2O2 ° = 0.68 V

*November 23, 2010*

**Genetics**

Quick question: which methods can be used to get DNA into cells? you can choose more than 1 answer A: Apply a high voltage B: Shoot DNA into the cells C: Infect with viruses D: Inject with a needle E: All of the above F: None of the above Is it all of the above? If so can ...

*November 21, 2010*

**Calculus**

Evaluate the integral: the integral of [5e^(2t)]/[1+4e^(2t)]dt. I have tried this problem so many ways and cannot come up with the correct answer :(

*November 18, 2010*

**Macroeconomics**

How would i approach this question? I don't necessarily want an answer. A "how to" would be better. (Simple Spending Multiplier) For each of the following values for the MPC, determine the size of the simple spending multiplier and the total change in real GDP ...

*November 14, 2010*

**math homework**

64/72--->8/9

*November 14, 2010*

**physics**

Atwood's Machine An Atwood's machine consists of two masses, and , connected by a string that passes over a pulley. If the pulley is a disk of radius and mass , find the acceleration of the masses.

*November 8, 2010*

**college physics**

A particular grinding wheel is a uniform solid disk of radius 8cm and mass 3kg. While the wheel is spinning at 50rad/s. A tool is pressed against its rim in a way that causes a friction force of 40N. If the disk is just "coasting" when the torque is applied, at what ...

*October 25, 2010*

**physics**

A hockey puck sliding on a frozen lake comes to rest after traveling 265 m. If its initial velocity is 4.2 m/s, what is its acceleration (assumed constant)? Answer in units of m/s2.

*October 24, 2010*

**probability!**

we were given a chart - "researchers developed the following tabel of joint probabilities of number of drinks per day and development of ulcers" and the question is a. what proportion of people have ulcers - how am i supposed to know htis b. what is the prob that ...

*October 21, 2010*

**PROB**

Researchers at the University of Pennsylvania School of Medicine have determined that children under 2 years old who sleep with the lights on have a 36% chance of becoming myopic before they turn 16. Children who sleep in darkness have a 21% chance of becoming myopic before ...

*October 19, 2010*

**probability!**

so i am asked to find the prob of a male professor - given that he is promoted. and the stats are female promoted = 3% female not promoted - 12% male promoted 17% male not promoted - 68% and i just wrote down that it is 17% is this true? ALso, i looked up in my book that P(A I...

*October 19, 2010*

**physics**

A 56 cm diameter wheel accelerates uniformly about its center from 130 rpm to 400 rpm in 3.2 s. (a) Determine its angular acceleration. Express your answer using two significant figures. (b) Determine the radial component of the linear acceleration of a point on the edge of ...

*October 18, 2010*

**Physics**

A 1.80 kg block slides on a frictionless horizontal surface. The block hits a spring with a speed of 2.00 m/s and compresses it a distance of 11.0 cm before coming to rest. What is the force constant of the spring?

*October 17, 2010*