Sunday

March 29, 2015

March 29, 2015

Total # Posts: 1,118

**chemistry**

Thank you :)
*April 12, 2014*

**chemistry**

1. Calculate pH of an acetate buffer containing 27.5 mM acetic acid (pKa is 4.74) and 50 mM sodium acetate. When a 30 mM aq solution of sodium acetate was prepared in the lab it had a pH of 8.8. Calculate the amount of acetic acid (in g) to be added to 0.5 L of this sodium ...
*April 12, 2014*

**Math**

5x^4-41x^3-87x^2-31x+10=0
*April 10, 2014*

**physic**

how many kcal of heat must be withdrawn from 4.56 kg of steam at 125 degrees C to change it to ice at -44.5 degrees C???
*April 9, 2014*

**physics**

how many Btu of heat are required to melt 8.35 lb of ice at 32 degrees F
*April 9, 2014*

**Need help on Physics!!**

Three uniform spheres are fixed at the positions shown in the diagram. Assume they are completely isolated and there are no other masses nearby. (a) What is the magnitude of the force on a 0.20 kg particle placed at the origin (Point P)? What is the direction of this force? (b...
*March 31, 2014*

**Please help me!!!!!**

Some fishing line is made out of nylon with Y =3.0!109Pa and breaking stress 7.7!107 Pa . It is 5.0 m long, you are holding one end, and it hangs down vertically. (a) When a 3.0-kg fish is attached to the bottom end, the fishing line elongates by 1.0 cm. What is its cross ...
*March 31, 2014*

**Another Physics**

At some point in the combustion cycle of an engine, the temperature of a combusted air-fuel mixture is 582 degrees Celsius. Given that the pressure in the mixture is 6.2 bar, determine the density of the mixture (in kilogram per cubic metre).
*March 28, 2014*

**physics**

At some point in the combustion cycle of an engine, the temperature of a combusted air-fuel mixture is 582 degrees Celsius. Given that the pressure in the mixture is 6.2 bar, determine the density of the mixture (in kilogram per cubic metre).
*March 27, 2014*

**physics**

A typical volume of a modern hot air balloon is 2500 cubic metres, and a typical maximum temperature of the hot air is 120 degrees Celsius. Given these figures, and an outside air temperature and density of 15 \(^{\circ}C\) and 1.225 \(kg/m^3\) respectively, compute the ...
*March 27, 2014*

**physics**

Suppose that, on a day when the outside temperature is 15 degrees Celsius, we fill a balloon with pure nitrogen gas, of which the molar mass is 28 grams per mole. Now suppose that we want to heat up a second (equally large) balloon containing air, such that it generates the ...
*March 27, 2014*

**physics**

Some say that the hot air balloons with which the Montgolfier brothers performed their first flight had a volume of 1700 cubic metres and could lift 780 kilograms (that includes the balloon, basket and payload). Assume that the balloon took off on a day when the sea level ...
*March 27, 2014*

**physics**

Thank you steve , please how do you know that each ballon occupies .01617m^3, please if possible give more precisions. I find 0,002746744 which doesn´t make sens to me. How do I make it ? thanks
*March 26, 2014*

**physics**

Thank you steve , please how do you know that each ballon occupies .01617m^3, please if possible give more precisions.
*March 26, 2014*

**physics**

Suppose that a party balloon is spherical, has a radius of 16 centimetres and is filled with helium. Furthermore suppose that we do our experiment under standard atmospheric conditions, when the air density is \(\rho = 1.225 kg/m^3\). How many of these balloons should a 75 ...
*March 26, 2014*

**physics**

Others say that the balloon was 23 metres high and 14 metres wide. Calculate the temperature of the air in the balloon (in degrees Celsius) for this situation as well
*March 26, 2014*

**Math**

Solve the problem. Round to the nearest cent. Joan wants to have $250,000 when she retires in 27 years. How much should she invest annually in her annuity to do this if the interest is 7% compounded annually? A) $1861.10 B) $3356.43 C) $2672.15 D) $937.86
*March 26, 2014*

**math**

2 trains leave the station at 325 one going east at 66 miles per hour the second going west at 82 miles per hour they are 111 miles apart what time is it
*March 25, 2014*

**math, economics**

Consider a market in which consumption of the good being traded generates a positive externality. There are 100 identical consumers, each with a utility function given by 1/2√q+m+√G, where G denotes the total level of consumption in the market. The good is sold by ...
*March 24, 2014*

**Linear Algebra**

Ok. I changed. number two to a number three to b
*March 18, 2014*

**Linear Algebra**

SO is all of them correct?
*March 18, 2014*

**Linear Algebra**

(-5.1)^0 a. 1 << b. 0 c. -5.1 d. -1 3g^-2 b^2 a. 3b^2/g^2 b. 3g^2 b^-2 <<< c. 3gb^-4 d. b^2/3g^2 3/g^-2 h^3 a. 3/g^2 h^3 << b. 3g^2/h^3 c. 6g/h^3 d. 3/gh
*March 18, 2014*

**Math**

In the Math Virtually Everywhere project you completed for this module, you learned all about cell phone plans. The best cell phone plan for a customer can vary based on how much they plan to talk. The plan that is the best deal for one customer may not be the best deal for ...
*March 14, 2014*

**Calculus**

A lighthouse is located on a small island 4 km away from the nearest point P on a straight shoreline and its light makes three revolutions per minute. How fast is the beam of light moving along the shoreline when it is 1 km from P? (Round your answer to one decimal place.)
*March 11, 2014*

**Calculus**

Two people start from the same point. One walks east at 5 mi/h and the other walks northeast at 7 mi/h. How fast is the distance between the people changing after 15 minutes? (Round your answer to three decimal places.)
*March 11, 2014*

**Math**

On Monday, Casey ran 5 miles. On Tues, she ran three and three fifths miles. How much further did she run on Mon than Tues? Then, on Wednesday she ran four and one half miles. How much further did she run on Wed than on Tues? Could someone show me how I would figure this out? ...
*March 9, 2014*

**Math**

A to B is 15 miles, B to C is 25, C to F is 21 F to E is 22 E to D is 14, D to B is 11 D to A is 10, A to B is 15 Each town (letters) must be connected to at least one other town. Towns A to F are to be connected. Calculate the minimum length of cable required...
*March 5, 2014*

**NEED HELP ASAP !!**

it would be 27,686 ft in difference
*March 4, 2014*

**math**

an initial population of 865 quail increases at a annual rate of 15%. write an exponential function to model quail population
*February 20, 2014*

**Life Orientation**

*cough* connections *cough* academy *cough,speaks with haste* im reporting you for these MAJOR CHEATS*cough* But really,why you getting all these free answers? You're never gonna succeed in life if you're living off of others smarts. And even when giving others the ...
*February 12, 2014*

**math**

Ruth makes a scale drawing of her room. She uses scale 3/2 in. : 1ft. In the drawing the dimensions are 18 in by 24 in. What are actual dimensions of room.
*February 10, 2014*

**BIOLOGY**

MONERA!!!!
*February 6, 2014*

**Math**

The white house, built 1792, is the oldest federal building in washington DC . The building has undergone extensive remodeling over the years. The main building is 4 stories high and is about 170 ft long by 85 ft wide. If a replica of the white house were made with a length of...
*January 29, 2014*

**Physics**

A stone is thrown directly upward from rest from ground level with initial speed 20.0 m/s; 1.50 s after that, a second stone is thrown directly upward from ground level with initial speed 18.0 m/s. (a) When are the stones at the same height? (b) What are the velocities of the ...
*January 26, 2014*

**Statistic **

Suppose you roll a die 10 times and record the proportion of sixes. Suppose you then conduct a simulation of this experiment, first 100 times, then 1000 times, and draw one histogram of the proportion of sixes found after 100 simulations and a second histogram of the ...
*January 26, 2014*

**math**

a dollar is to a dime as a meter is to a..
*January 22, 2014*

**math**

a dollar is to a dime as a meter is to a..
*January 22, 2014*

**physics**

An animal-rescue plane ﬂying due east at 40 m/s drops a bale of hay from an altitude of 73 m . The acceleration due to gravity is 9.81 m/s. If the bale of hay weighs 177 N , what is the momentum of the bale the moment it strikes the ground? part 2 At what angle of ...
*January 3, 2014*

**physics**

An animal-rescue plane ﬂying due east at 40 m/s drops a bale of hay from an altitude of 73 m . The acceleration due to gravity is 9.81 m/s^2. If the bale of hay weighs 177 N , what is the momentum of the bale the moment it strikes the ground? Please help!
*January 2, 2014*

**math**

Forces are applied to two ropes which are attached to the bumper of a stalled car. If F1 = 100 lbs at an angle of θ1 = 58 degrees, find the necessary magnitude and direction of force F2 so that the resultant force is 190 lbs in the direction shown.
*December 6, 2013*

**math**

Two squirrels are sitting on a rope as shown. The tension in segment BD is TBD = 6.3 lb at an angle of ϕ = 47 degrees. The tension in segment AB is TAB = 5.229 lb. Find the weight of the squirrel at B and the angle α.
*December 6, 2013*

**math**

A farmer's tractor has gotten stuck in a muddy pasture. To try to free the tractor, the farmer ties a rope to a tree and the front of her tractor, then pulls sideways in the middle of the rope with a force of F = 510 N. Angles of θ = 5 degrees are formed as shown. ...
*December 6, 2013*

**MATH**

The table that follows shows the relationship between the boiling temperature of water (°F) and the altitude (per thousand feet): Boiling Point of Water Altitude (1000 ft.) Temperature (°F) 8 197.6 4.5 203.9 3 206.6 2.5 207.5 Gemma and Tessa need to find the rate of ...
*December 1, 2013*

**algebra 2**

The table that follows shows the relationship between the boiling temperature of water (°F) and the altitude (per thousand feet): Boiling Point of Water Altitude (1000 ft.) Temperature (°F) 8 197.6 4.5 203.9 3 206.6 2.5 207.5 Gemma and Tessa need to find the rate of ...
*November 30, 2013*

**algebra 1**

The table that follows shows the relationship between the boiling temperature of water (°F) and the altitude (per thousand feet): Boiling Point of Water Altitude (1000 ft.) Temperature (°F) 8 197.6 4.5 203.9 3 206.6 2.5 207.5 Gemma and Tessa need to find the rate of ...
*November 29, 2013*

**algebra 1**

Ashley is the manager of a theater. She has $240 to spend on posters to advertise a new play. If she buys small posters only, Ashley can print 48 posters for $240. If she buys large posters only, Ashley can print 30 posters for $240. A. Write an equation that can be used to ...
*November 29, 2013*

**Math **

what is the unit rate of 5 divided 12 1/2 and how do you solve it ?
*October 29, 2013*

**Statistics**

Wow! Thank you for the help! Also, wouldn't the 90% confidence interval be 9.6% to 12.8%? Also, would the margin of error be 3.2 or 1.6? Thank you!
*October 27, 2013*

**Statistics**

Direct mail advertisers send solicitations (that is "junk mail") to thousands of potential customers in the hope that some will buy the company's products. The response rate is usually quite low. Suppose a company wants to test the response rate for a new flyer ...
*October 27, 2013*

**Statistics**

We have calculated a 95% confidence interval for a proportion and would prefer the confidence interval to be more precise, that is narrower. Using the same sample, we can narrow the confidence interval using which of the following? A) increasing the confidence level B) ...
*October 27, 2013*

**Statistics**

In a poll of voters in a certain city, 32% said that they backed a bill which would limit growth and development in their city. The margin of error was reported as 1.7% with 90% confidence. Determine the bounds for the confidence interval. A) (88.3%, 91.7%) B) (30%, 34%) C) (...
*October 27, 2013*

**Statistics**

Which of the following is not an assumption or condition that needs to be checked for the one-proportion z-interval? A) Success/Failure Condition B) > 10% condition C) Independence D) < 10% Condition E) Randomization Is the answer C?
*October 26, 2013*

**Statistics**

A study of 902 decisions (to grant parole or not) made by the Nebraska Board of Parole produced the following 95% confidence interval: (56.1%, 62.5%) What is the margin of error? A) 1% B) 6.4% C) 59.3% D) 3.2% Is the answer C?
*October 26, 2013*

**Chemistry**

what's the density of a cube of an unknown substance if mass is 45.2g and the side of a cube is 3.2cm?
*October 24, 2013*

**algebra**

a 9 foot board is cut into two pieces .one is 3.5 feet longer than the other. how long is the longer piece?
*October 24, 2013*

**Science**

A rock with a mass of 0.3 kg has a kinetic energy of 43.2 j when thrown. What was the speed at which it was thrown?
*October 14, 2013*

**Science**

A boy standing on a high diving board has a mass of 45 kg and a total gravitational potential energy of 2700 j. How high is the diving board? What is the answer to this question and how did you come up with the answer.
*October 14, 2013*

**science**

What fraction of piperazine (perhydro-1,4-diazine) is in each of its three forms (H2A, HA–, A2–) at pH 8.67? The acid dissociation constant values for piperazine are Ka1 = 4.65×10–6 and Ka2 = 1.86×10–10.
*October 6, 2013*

**Math Calculator Question**

How would I plug the following formula in a TI-30X calculator: P(5)= (10 C 5)(0.20^5)[0.80^(10-5)] When I try to do it, I get 0.000104858, but that is not the correct answer.
*October 6, 2013*

**science **

You prepare a buffer solution from 10.0 mL of 0.100 M MOPS (3-morpholinopropane-1-sulfonic acid) and 10.0 mL of 0.079 M NaOH. Next, you add 1.00 mL of 7.15 × 10-6 M lidocaine to this mixture Denoting lidocaine as L, calculate the fraction of lidocaine present in the form LH
*October 6, 2013*

**Physics**

If a car is going .197 meters per second, how long will it take to go 5 kilometers (assuming the ground is perfectly flat).
*October 6, 2013*

**Statistics**

A manufacturer ship toasters in cartons of 10. In each carton, they estimate a 20% chance that one of the toasters will need to be sent back for minor repairs. What is the probability, that in one carton there will be 5 toasters that need repair? I have no idea on where to ...
*October 5, 2013*

**Statistics**

A small software company bids on two contracts. It anticipates a profit of $60,000 if it gets the larger contract and $25,000 if it gets the smaller contract. The company estimates that there is a 32% chance it will get the larger contract and a 62% chance it will get the ...
*October 5, 2013*

**Statistics**

The soccer team's shirts have arrived in a big box and people start grabbing them. The box contains 7 medium, 12 Large, and 11 extra-large shirts. What is the probability that the first 4 shirts are all extra large? I have been struggling with the problem for an hour and ...
*October 1, 2013*

**English/ Writing**

from what my notes say - this is going to be an attempt to create integration through the use of a new term/ concept that either combines disciples or some aspect of the disciplines.
*September 29, 2013*

**English/ Writing**

What are some bad compound concepts and what makes them bad?
*September 29, 2013*

**8th Grade Math**

25/50 x 60/70 x 100/200= 72 6/7
*September 24, 2013*

**Math**

Write remainder as a fraction in simplest form: 567/15=
*September 24, 2013*

**Math**

Find the value of k so that the line containing the points (k,−8) and (−3,−5) is parallel to the line containing the points (9,7) and (12,5).
*September 14, 2013*

**math**

The low temperature on friday was five degrees below zero celsius. On saturday the low temperature was eight degrees below zero celsius. What integer best represents the low temperature on saturday in degrees celsius?
*September 9, 2013*

**C++**

Write a complete, working program that will do the following: Suppose you want to write a program to calculate the total cost of an item that has sales tax added. If a given item costs 14.97, and the tax rate is 6.7%, display the following information: a) The original cost of ...
*September 9, 2013*

**Math**

What is the shape of the power function that controls the end-behavior?
*September 3, 2013*

**English**

Need help with this assignment. Please and thanks. The first composition should be about making a decision. Since this will be a narrative piece of writing, chronological order will probably work best. The second composition will be about the American way of life. In it, ...
*August 9, 2013*

**Math (please help Steve)**

A crippled rook can move on a chessboard in the following way: from a square, it can move to an adjacent square sharing a common side, and every two consecutive moves must be at right angles (i.e., the rook makes a 90∘ turn at every move). A cycle is a sequence of ...
*August 7, 2013*

**maths**

a roofer charges $25 per hour for himself and $15 per hour for his assistant. On a recent job the assistant worked 2 hours less than the roofer and the tot charge for labour was $290. Let r be the number of hours that the roofer worked. Which of the following equation can be ...
*August 7, 2013*

**maths**

1)a linear function is represented by f(x)=2x+7 which of the following functions would be parallel to that of the function above a)f(x)=2x-7 b)f(x)=x+7 c)f(x)=x-7 d)f(x)=-1/2x+7 e)f(x)=-1/2x-7 I choose b 2)water is pumped into an empty tank at a constant rate. after 2 minutes ...
*August 7, 2013*

**Math (please help steve)**

Circles Γ1 and Γ2 have centers X and Y respectively. They intersect at points A and B, such that angle XAY is obtuse. The line AX intersects Γ2 again at P, and the line AY intersects Γ1 again at Q. Lines PQ and XY intersect at G, such that Q lies on line ...
*August 7, 2013*

**Math (please help steve)**

A crippled rook can move on a chessboard in the following way: from a square, it can move to an adjacent square sharing a common side, and every two consecutive moves must be at right angles (i.e., the rook makes a 90∘turn at every move). A cycle is a sequence of squares...
*August 7, 2013*

**math (please help steve)**

A crippled rook can move on a chessboard in the following way: from a square, it can move to an adjacent square sharing a common side, and every two consecutive moves must be at right angles (i.e., the rook makes a 90∘turn at every move). A cycle is a sequence of squares...
*August 6, 2013*

**math (please help steve)**

Circles Γ1 and Γ2 have centers X and Y respectively. They intersect at points A and B, such that angle XAY is obtuse. The line AX intersects Γ2 again at P, and the line AY intersects Γ1 again at Q. Lines PQ and XY intersect at G, such that Q lies on line ...
*August 6, 2013*

**physics**

a feather is dropped on the moon from a height of 1.4 meters.the acceleration of the moon is 1.67 m/s determine the time for the feather to fall on the surface of the moon
*August 5, 2013*

**physics**

a feather is dropped on the moon from a height of 1.4 meters.the acceleration of the moon is 1.67 m/s determine the time for the feather to fall on the surface of the moon
*August 5, 2013*

**math word problem**

sam needs to clean the window on his house. he has a 25-foot ladder and places the base of the ladder 10 feet from the wall of the house. A) how high up the wall will the ladder reach? B) if his windows are 20 feet above the ground, what is the farthest distance the baes of ...
*August 1, 2013*

**MAT LAB**

9_1_1 4 &0.4 9_2_1 99.42,99.98,100.54 9_3_1 don't know...
*July 19, 2013*

**Physics**

9_1_1 4 &0.4 9_2_1 99.42,99.98,100.54 9_3_1 don't know...
*July 18, 2013*

**Material Sciences**

9_1_1 4 &0.4 9_2_1 99.42,99.98,100.54 9_3_1 don't know...
*July 17, 2013*

**writing**

1)Al:(who's,whose)car is in my parking space? 2)Ben:(it's,its)Fred's. 3)Al:(know,no,his car is red.It might be the Jones'. 4)Ben:(their,there,they're)car is green.(here,hear)come Bob and Tony. 5)Tony:Hi!Isn't my (knew,new)car(grate,great)? 6)Al:(you'...
*July 11, 2013*

**Writing**

thank you
*July 11, 2013*

**Writing**

On the whole, peoples experiences with department store cards are good except when they loose a card. Can you tell me if i used except and peoples corectly
*July 11, 2013*

**Math**

The Chicago Art Museum's Renaissance display consists of four hallways bordered around a square courtyard. A single guard is assigned to patrol the four hallways. When the guard starts working, he begins in one of the corners and walks clockwise. When he arrives at a ...
*July 2, 2013*

**Physics**

A thin aluminum ring hangs vertically from a torsion spring. A torsion spring when twisted exerts a restoring torque given by τ=−κθ where θ is the angle of twist. Suppose that the ring undergoes small torsional oscillations while it is being cooled ...
*July 1, 2013*

**Math-algebra-Steve**

The sequence {an} satisfies a0=1,a1=213, and an=2an−1+an−2 for all n≥2. Let S=∑i=1 to infinity a[i-1]/(a[i]^2-a[i-1]^2) What is the value of 1/S?
*June 24, 2013*

**Physics**

0.700
*June 24, 2013*

**Math**

The sequence {an} satisfies a0=1,a1=213, and an=2an−1+an−2 for all n≥2. Let S=∑i=1 to infinity a[i-1]/(a[i]^2-a[i-1]^2) What is the value of 1/S
*June 24, 2013*

**Physics**

A small coin is inside a bowl. The bowl is a surface of revolution of the curve y=100x^4 m^-3. This coin slides around the inside of the bowl at a constant height of y=0.01 m above the bottom of the bowl. What is its angular velocity in rad/s? Accel due to gravity = 9.8 m/s^2
*June 24, 2013*

**Calculus 2**

(x^3+2x^2-15x+1)/(x^2+2x-15) from 0 to 7
*June 23, 2013*

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