Wednesday

February 10, 2016
Total # Posts: 1,728

**Math**

A gas expands against a constant external pressure of 1.7 bar until its volume has increased from 5.4 L to 8.9 L. During this process it absorbs 640.0 J of heat from the surroundings. Calculate the energy change of the gas.
*December 2, 2011*

**Physics**

Carmen and Judi dock a canoe. 83.0-kg Carmen moves forward at 4.3 m/s as she leaves the canoe to step onto the dock. At what speed and in what direction do the canoe and Judi move if their combined mass is 115 kg? (Use a positive number if the canoe moves away from Judi.)
*November 30, 2011*

**physics**

The outer edge of a truck tire that has a radius of 50 cm has a velocity of 29 m/s. What is the angular velocity of the tire in rad/s?
*November 30, 2011*

**physics (biomechanics)**

briefly explain how an athlete competing in the long jump can prevent the trunk from pitching forward after take-off
*November 30, 2011*

**Chemistry**

MgCl2(aq) + 2 NaOH(aq) --> Mg(OH)2(s) + 2 NaCl(aq) How many grams of Mg(OH)2 would form if 50.00 mL of 0.9750M NaOH were combined with 50.00 mL of 0.8820 M MgCl2?
*November 26, 2011*

**Chemistry**

MgCl2(aq) + 2 NaOH(aq) --> Mg(OH)2(s) + 2 NaCl(aq) How many grams of Mg(OH)2 would form if 50.00 mL of 0.9750M NaOH were combined with 50.00 mL of 0.8820 M MgCl2?
*November 26, 2011*

**chemistry**

How many grams of LiOH would be needed to make a 500.0 mL of 0.340 M LiOH?
*November 26, 2011*

**Chemistry**

Complete the table by filling in the formula for the ionic compound formed by each pair of cations and anions, as shown for the first pair. Ion K+ NH+4 Mg2+ Fe3+ Cl- OH- CO3 2- PO3- 4 Complete the fourth row of the table.
*November 16, 2011*

**geometry**

Write a two-column proof of Theorem 6-2-3, which is: If a quadrilateral is a parallelogram, then its consecutive angles are supplementary.
*November 15, 2011*

**literary**

The snake hissed loudly and attacked the rat. what literary term does this use?
*November 14, 2011*

**trig**

Cos(-11/12) use the sum or difference formula to find the exact number
*November 13, 2011*

**Trig**

cos(-11pi/12)
*November 13, 2011*

**history**

ohh thank you so much i got my answer!! thank you again!
*November 13, 2011*

**history**

i need to know how cleopatra had an impact on the roman republic or the roman empire? thank you!
*November 13, 2011*

**Chemistry**

How do valence electrons play a part in the physical or chemical charactersitics of an element?
*November 11, 2011*

**chemistry**

yes
*November 11, 2011*

**Chemistry**

If you had excess chlorine, how many moles of of aluminum chloride could be produced from 20.0 g of aluminum? If you had excess aluminum, how many moles of aluminum chloride could be produced from 25.0 g of chlorine gas Cl2?
*November 6, 2011*

**religion**

who wrote about one-fourth of the bible? thanks
*November 5, 2011*

**chemistry**

thank you i figured out how to do it right before you posted this :)
*November 3, 2011*

**chemistry**

how do you find how many hydrogens there would be in 2,5,6 trimethylnonane?
*November 3, 2011*

**chemistry**

how many hydrogens would there be in 2,5,6 trimethylnonane and how do you find them
*November 3, 2011*

**calculus**

a closed box with square base is to have a V= 2000in^3. The material for the top and bottom of the box is to cost $3 per square inch and the material for the sides is the cost $1.50 per square inch. If the cost of the material is to be the least, find the dimensions
*November 2, 2011*

**Math**

What do you call an angle more than 90 degrees and less than 180 degrees?
*October 27, 2011*

**AP US History**

Compare and Contrast the effectiveness of Washington's and Adams' presidencies in obeying and promoting the Constitution during their administrations. So far I have: The main compromises made when writing and ratifying the Constitution were the Three-Fifths Compromise...
*October 26, 2011*

**Physics**

A 2.50 mass is pushed against a horizontal spring of force constant 26.0 on a frictionless air table. The spring is attached to the tabletop, and the mass is not attached to the spring in any way. When the spring has been compressed enough to store 15.0 of potential energy in ...
*October 21, 2011*

**statistics**

f(y)= (1/c)e^(-y/2) if y is greater than or equal to 0 and f(y)=(1/c)e^(y/2) if y is less than 0 a) What is c? b)What is the probability distribution function?
*October 19, 2011*

**College Algebra**

Factor the polynomial by pulling out the GCF 6r^2+12r-15
*October 18, 2011*

**College Algebra**

Sorry, I posted in the wrong place :(
*October 18, 2011*

**College Algebra**

Factor the polynomials by pulling out the GCF 6r^2+12r-15
*October 18, 2011*

**Physics**

Commercial aircrafts usually bank at an angle of no more than 30.0 degrees when turning. At 30.0 degrees of bank, how many g's of lift must the aircraft pull if it is to maintain uniform circular motion without losing altitude?
*October 17, 2011*

**Physics w/ Calc**

A baseball approaches home plate at a speed of 43.0 m/s, moving horizontally just before being hit by a bat. The batter hits a pop-up such that after hitting the bat, the baseball is moving at 54.0 m/s straight up. The ball has a mass of 145 g and is in contact with the bat ...
*October 16, 2011*

**chemistry**

How many grams of K3PO4 would be needed to prepare a 1.73 M solution in a total volume of 427 mL?
*October 12, 2011*

**chemistry**

How many grams of K3PO4 would be needed to prepare a 1.73 M solution in a total volume of 427 mL?
*October 12, 2011*

**4th grade math**

what is 2 x what = 14
*October 12, 2011*

**science**

Sam weighs 720 N on earth and 120 N on the moon. What does this tell you about the value of gravity on the moon?
*October 9, 2011*

**statistics**

100
*October 7, 2011*

**Physics **

How would I calculate the speed of a block before it leaves an incline if I have: the height of the incline, h=0.60m the height of the table its on H=0.952m and the distance traveled on the track d= 1.18m ? I have the acceleration calculated as 4.9 which is correct but I don&#...
*September 28, 2011*

**chemistry**

Fe2+(aq) + Cr2O7 2- (aq) →Fe3+(aq) + Cr3+(aq) Balance the equation by using oxidation and reduction half reactions. What is smallest possible integer coeﬃcient of Cr3+ in the combined balanced equation?
*September 28, 2011*

**statistics**

In order to study whether IQ level is related to birth order, data were collected from a sample of 540 students on their birth order (Oldest/In Between/Youngest) and their score on an IQ test. The data collected in this study would be best displayed using: which one: (a) a pie...
*September 26, 2011*

**english **

need help writing a poem about facing challenges
*September 25, 2011*

**english **

need help writing a poem about facing challenges
*September 25, 2011*

**Trig**

The point (-5/12) is on the terminal side of an angle theta in standard position. Find Sin theta, cos theta and tan theta Thank You!
*September 21, 2011*

**math**

oh thank you so much:)
*September 21, 2011*

**math**

i need help on any 3 numbers that add up to -84 and any 3 number that add up to 54 thanks
*September 21, 2011*

**physics**

2,000 m/s^2
*September 17, 2011*

**math**

kindergarten-fifth grade= a total of 6 grade levels 6 grade levels times 3 classes for each grade level= a total of 18 classes for the whole school 18 classes times 27 students per classroom= 486 the final answer is: about 486 students
*September 14, 2011*

**physics**

A pilot flying low and slow drops a weight; it takes 2.9 to hit the ground, during which it travels a horizontal distance of 115 . Now the pilot does a run at the same height but twice the speed. How much time does it take the weight to hit the ground?
*September 12, 2011*

**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*