Wednesday

October 26, 2016
Total # Posts: 919

**probability**

A dictionary contains 80,000 words, of which a certain student knows 30,000. If 100 of the 80,000 words are selected at random from the dictionary without replacement, find the probability:the student knows exactly 40 of the 100 words

*October 11, 2011*

**Physics**

yes, I added the vectors, of the charges. for a uniform line, E= kλ/R. Since the charge on the line is negative, it goes towards the line, and only has an x component of E= -12 kN/C. For the point charge, which is negative, E is away from the source, I got E=30.2 kN/C for...

*October 9, 2011*

**Physics**

An infinitely long line charge of uniform linear charge density λ = -3.00 µC/m lies parallel to the y axis at x = -2.00 m. A point charge of 4.70 µC is located at x = 1.50 m, y = 2.50 m. Find the electric field at x = 2.50 m, y = 2.00 m. I get 23.7 kN/C, why ...

*October 9, 2011*

**algebra**

true or false, Distributive property says that you can give out a factor to both numbers in a sum then add them together afterward

*October 6, 2011*

**Geometry**

Let x = acute angle 1 and 4x + 17 ext angle Let y = acute angle 2 and 6x + 23 ext angle x + 4x + 17 = 180 X=32.6 y =90-x = 90-32.6 = 57.4 4(32.6) + 17 = 147.4 Note: Cannot use x value for ext. 6x+23. Y is different acute angle. Vice versa.

*October 5, 2011*

**science**

a can potatoes has the following data: recall 4-9system carbs=22 fat is 10 grams and protien is 13 find the percentage of each if the calories = 275

*October 4, 2011*

**chemistry**

A student estimated the volume of liquid in a beaker as 200 mL. When she poured the liquid into a graduated cylinder, she measured the volume as 216 mL. What is the percent error of the estimated volume from the beaker, taking the measurement in the graduated cylinder as the ...

*October 2, 2011*

**History**

Is it a false statement to say that every single group of people who have wished to establish their independence and their own individuality from a corrupt form of government will eventually succeed at doing so? Like with segregration and everything and like i don't know ...

*September 27, 2011*

**math pre-algebra**

1.x/4+2=1 2.-3+x/1=-3 please show steps thanks

*September 22, 2011*

**math**

x/4+2=1 -3+x/1=-3 please show steps thanks

*September 22, 2011*

**math**

2-4n=10 please show how you get the answer thanks

*September 22, 2011*

**math**

-3+x/1=-3

*September 22, 2011*

**spanish**

Form complete sentences using the information provided. Use indirect object pronouns and the present tense of the verbs Javier / prestar / el abrigo / a Gabriel

*September 18, 2011*

**grammar**

circle the words that have the long a or e sound stream stem let man plains saw land late calm text breed endless play part flat

*September 8, 2011*

**geometry**

i don't know!!!

*August 24, 2011*

**phsics**

A drag racer, starting from rest, speeds up for 402 m with an acceleration of +16.0 m/s2. A parachute then opens, slowing the car down with an acceleration of -5.60 m/s2. How fast is the racer moving 2.90 102 m after the parachute opens?

*August 23, 2011*

**math**

in a class of 28 sixth graders , all but one of the students are 12 years old. which two data measurements are the same for the student's ages? What are those measurements?

*August 10, 2011*

**Spanish**

Yes I understand. I kept saying the two options out loud. What I was confused was, I thought choice a meant, "Good, you pay tomorrow." But I'm starting to understand the meaning behind attaching "te" behind pagar. I had trouble understanding this ...

*August 9, 2011*

**Spanish**

Yo te puedo pagar manana. (accent on n) Would the response be a. Bueno, pagate manana. (accent on a and n) b. No, pagame ahora mismo. (accent on a) And can you explain why? Gracias

*August 9, 2011*

**Spanish**

I always thought Ustedes meant "they." I've also heard it as "you all (plural)". So when a question being given has the Uds. conjugation of the infinitive, are we suppose to answer back in the Uds. form or nosotros form? For example: A que hora van a ...

*July 11, 2011*

**Environmental Science**

If global energy policies lead to stabilisation of CO2 concentrations at 660 p.p.m., what would the resulting increase in GMST be (to one decimal place)? In subsequent parts of the question this is referred to as the UN’s ‘de facto temperature target’

*July 11, 2011*

**science**

how many seconds you will reached the distance of 200 m. if your acceleration at 2m/s/s?

*July 6, 2011*

**science**

how far you will move in 20 seconds if your acceleration at 2m/s/s?

*July 6, 2011*

**science**

what is the velocity of a body moves from rest moves the distance of 10 m. and acceleration 2 m/s/s?

*July 6, 2011*

**prime factiozation**

i am 25 years old and i need to the find the lcm of 15 years and 30 years

*June 27, 2011*

**Math**

A chemistry teacher needs 2.5 liters of a sulfuric acid solution that is 20% sulfuric acid and 80% water . He has 2 liters of a 15% sulfuric acid solutionleft over from earlier laboratory exercises. He also has 44 liters of a 50% solution. Let x represent the number of liters ...

*May 31, 2011*

**Math**

correct

*May 30, 2011*

**math**

the volume of a container that is 8" long 4" long and3' high is _cu in. please help

*May 29, 2011*

**math**

a 22" diameter circle has an area of_sq in.

*May 29, 2011*

**math**

dy/dx=2/27(x-3)√((x^2-6x+23)/y)

*May 23, 2011*

**Physics**

Find the fg y component because that is equal to the "n" in the equation: F(static friction) = mu x n

*May 21, 2011*

**calculus**

Hello drwls. Please can you explain how you get 72sqrt2+c. Surely, if it is 50.911=50.911+c, if one subtracts either side c=0? Am I missing something?Thank you for your help.

*May 20, 2011*

**calculus**

Please help. I have an implicit answer to a differential equation of 18y*sqrt(y)=(2(x^2-6x+23)^3/2)/3 plus arbitrary constant. What is the particular solution to this for which y=2 when x=1. And then express this particular solution answer in an explicit form. Please help and ...

*May 20, 2011*

**calculus**

Please help. How do I seperate the variables in the following differential equation dy/dx=(2/27)(x-3)then square root (x^2-6x+23)/y where (y>0). Then give general solution in implicit form. Thank you so much if you can help.

*May 19, 2011*

**litres and millilitres**

1/10L=ml

*May 11, 2011*

**Math**

Solve for x. 3^(2x)-2*3^(x+5)+3^10= 0

*May 2, 2011*

**calculus**

let R be the region bounded by the x-axis, the graph of y=sqrt(x+1), and the line x=3. Find the area of the region R

*May 1, 2011*

**Science/Math**

We have 30 grams of clay. We understand that Density=Mass/Volume. We understand that the Density of water is 1.0 and in order for the clay boat to float in the water Density needs to be less than 1.0. So my question is using 30 grams of clay what design will allow me to hold ...

*April 24, 2011*

**chemistry**

Is it possible to calculate the value of the solubility product constant without being given any concentrations?

*April 23, 2011*

**Compound math**

$24,000 is invested for 5 years with APR of 2% in daily compounding.What is the balance in account after 5 years?

*April 19, 2011*

**business**

How did U.S. manufacturers become vulnerable to offshore outsourcing? Give examples to support your answers.

*April 9, 2011*

**Chemistry**

Write a net ionic equation and calculate K for the reaction in aq between acidic acid and sodium hydroxide. Given Ka (acidic acid) = 1.8 x 10^-5

*April 4, 2011*

**social studies**

Ads that rely on the testimonials of people who have used the product are using what technique?

*April 4, 2011*

**Science**

Hello van some one show me how to draw a dot and cross diagramm for 1 lithium atom and 1 fluorine atom(Lif) and also a diagram for 1 magnesium atom and 1 oxygen atom (MgO) Thankyou Paul.

*March 28, 2011*

**chemistry**

What is the molarity of Cl− ions at the stoi- chiometric point? Answer in units of mol/L.

*March 26, 2011*

**chemistry**

How do I calculate 50ml of a 50mM sodium momophosphate buffer solution

*March 23, 2011*

**Chemistry**

The maximum solubility of silver sulfate, Ag2SO4 [molar mass = 312], is 4.50 g/L at 25°C. Silver sulfate dissociates by the reaction below: Ag2SO4(s) <--> 2 Ag+ (aq)+ SO4¯² (aq) 1.What are the [Ag+] and [SO4¯²] in a saturated solution of silver ...

*March 20, 2011*

**Physics**

A car travels 12 km north from oakville, then 8.0 km westto springfield .what is the magnitude of the displacement of a helicopter that travels directly from oakville to springfield

*March 16, 2011*

**Trigonometry**

Can you verify this identity? cos(4x)cos(2x)= (1/2)[cos8x+cos2x]

*March 14, 2011*

**Math**

Oh, I think I got it. Are the answers (-15,18) and (1,2)?

*March 13, 2011*

**Math**

At what points does the line y+x-3=0 intersect the curve 2y=6x+2(x^2)-(y^2)?

*March 13, 2011*

**Physics**

thank you so much!

*March 9, 2011*

**Physics**

I am a little confused about kinetic and potential energy regarding roller coasters. I understand that the first hill has to be the highest to gain the potential energy (PE). I hope someone can help with this example I just made up to help me understand: 1st Hill: 50 m from ...

*March 9, 2011*

**Chemistry**

A student titrates 0.100M KOH into 50.00 ml of weak acid HX. The pH of the solution is 4.25 after 20.00 ml of the base has been added, and equivalence point is reached when 40.00 ml of the base is added. 1. What is the concentration of the acid, HX ? 2. What is the Ka value of...

*March 9, 2011*

**Physics**

A bus starts from rest at a bus stop and accelerates at a rate of 1.12 m/s^2 for 11.0s. It runs at constant speed for 80.0 s and slows at a rate 1.20 m/s^2 until it stops at the next bus stop. (a) What is the maximum speed attained. (b) Find the total distance covered.

*March 8, 2011*

**math**

Rail earns 10% commission on each guitar and 15% commission on each keyboard he sells. In two week he sold 5 guitars that cost$260 each and 2 keyboards that costv$420 each. How much commission did he earn on these seven items?

*March 3, 2011*

**gr. 12 biology**

My teacher wants me to calculate the rate of enzyme activity (1/s) I'm given the temperatures: 0 , 15, 30, ,50, and 80 (degrees celsius) AND the times 8.74, 18.83, 14.30, 34.22, and infinity respectively (seconds obviously, these are the times it took the enzyme to react...

*February 27, 2011*

**gr. 12 biology**

My teacher wants me to calculate the rate of enzyme activity (1/s) I'm given the temperatures: 0 , 15, 30, ,50, and 80 (degrees celsius) AND the times 8.74, 18.83, 14.30, 34.22, and infinity respectively (seconds obviously, these are the times it took the enzyme to react...

*February 27, 2011*

**Math**

Suppose that y≤5x,3x≤y and 14x+15y≤1 together with 0≤x, 0≤y. The maximum value of the function y+x on the resulting region occurs at x=? and y=? The maximum value of the function is ?

*February 26, 2011*

**physic**

If the work required to speed up a car from 13 km/h to 20 km/h is 6.5×103 J, what would be the work required to increase the car’s speed from 20 km/h to 35 km/h?

*February 23, 2011*

**Physics**

I can't figure this question out. If there are three weights attached to the corners of an equilateral triangle with side length 10 cm Measured from the bottom left corner, what is the center of mass of this object if M1 = 0.1 kg, M2 = 0.2 kg, and M3 = 0.3 kg?

*February 22, 2011*

**Chem**

What is the pressure in a 2.00 L container which holds 0.100 mol of methane and and 0.200 mol of carbon dioxide at standard temperature?

*February 17, 2011*

**Physics**

Calculate the magnitude of the potential difference between points a and b in the figure if R1=2.36 Ù, R2=4.29 Ù,and R3=10.08 Ù.

*February 17, 2011*

**Chemistry**

What is the pressure in a 2.00 L container which holds 0.100 mol of methane and and 0.200 mol of carbon dioxide at standard temperature?

*February 17, 2011*

**Chemistry- Drbob-help#3**

Thanks I understand now what I did wrong you have been a big help.

*February 10, 2011*

**Chemistry- Drbob-help#3**

I still need help with #3 I'm not sure how I got 1.14M. I have tried to do the problem over, but I not coming up with my original answer of 1.14M. Somehow I am missing a step. Please show work for the 1.14M Thanks Question#9 reads exactly as written. A student makes a ...

*February 10, 2011*

**Chemistry- Drbob-help**

I have placed the answer I got please help. A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 870mL 2. Calculate the % ...

*February 9, 2011*

**chemistry**

How much NH3 can be produce from 20 liter 32,5 wt%(NH2)2CO (urea) aqueous solution. The reaction path way is : (NH2)2CO +H2O= 2NH3+ CO2 Thanx

*February 9, 2011*

**Chemistry**

A student dissolves 18.9 grams of Zn(NO3)2 [molar mass = 189] in enough water to make 500.0 of solution. A 100.0 ml portion of this solution is diluted to 1000.0 ml.What is the [NO3¯ ] in the second solution? A) 0.0100M B) 0.0200M C) 0.0300M D) 0.0400M E) 0.0500M

*February 9, 2011*

**Chemistry**

A student dissolves 18.9 grams of Zn(NO3)2 [molar mass = 189] in enough water to make 500.0 of solution. A 100.0 ml portion of this solution is diluted to 1000.0 ml.What is the [NO3¯ ] in the second solution? A) 0.0100M B) 0.0200M C) 0.0300M D) 0.0400M E) 0.0500M

*February 8, 2011*

**Math**

The reduced row echelon form of the matrix -1/2 1/2 3/2 -3/2 2 3/2 1/2 -3/2 9/2 is?

*February 6, 2011*

**Math**

The reduced row echelon form of the matrix -1/2 1/2 3/2 -3/2 2 3/2 1/2 -3/2 9/2 is?

*February 5, 2011*

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...

*February 1, 2011*

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...

*February 1, 2011*

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...

*January 31, 2011*

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...

*January 31, 2011*

**Chemistry**

what volume of 1.015mol/L magnesium hydroxide is needed to neutralize 40.0mL of 1.60mol/L hydrochloric acid. Can you work it out please? Thanks!

*January 27, 2011*

**Chemistry**

what volume of 1.015mol/L magnesium hydroxide is needed to neutralize 40.0mL of 1.60mol/L hydrochloric acid. Can you work it out please? Thanks!

*January 27, 2011*

**Chemistry**

8.76g of aluminum sulphide is added to 0.0350L of 0.250mol/L lead(II)nitrate solution. calculate the maximum mass of precipitate, PbS that can form

*January 27, 2011*

**Chemistry**

The following data is collected for the decomposition of methy isonitrile at various tempertures: Temp.(C)---{k(/s)} --- lnk---1/T 290--- {2.52*10^-5}--- ?--- ? 299--- {5.25*10^-5}--- ? --- ? 330--- {6.30*10^-4}--- ?--- ? Complete the table above and, using your graphing ...

*January 26, 2011*

**Chemistry**

The following data is collected for the decomposition of methy isonitrile at various tempertures: Temp.(C)---{k(/s)} --- lnk---1/T 290--- {2.52*10^-5}--- ?--- ? 299--- {5.25*10^-5}--- ? --- ? 330--- {6.30*10^-4}--- ?--- ? Complete the table above and, using your graphing ...

*January 26, 2011*

**Chemistry**

The following data is collected for the decomposition of methy isonitrile at various tempertures: Temp.(C) k(/s) lnk 1/T 290--- 2.52*10^-5 ? ? 299--- 5.25*10^-5 ? ? 330--- 6.30*10^-4 ? ? Complete the table above and, using your graphing calculator determine the value of the ...

*January 24, 2011*

**Chemistry**

NH4HS(s )<=>NH3(g)+ H2S(g) ∆H = +93 kilojoues The equilibrium,above is established by placing solid NH4HS in an evacuated container at 25degreesC. At equilibrium, some solid NH4HS remains in the container. Predict and explain the following. The effect on the ...

*January 14, 2011*

**Chemistry**

NH4HS(s) NH3(g) + H2S(g) ∆H_ = +93 kilojoules The equilibrium above is established by placing solid NH4HS in an evacuated container at 25°C. At equilibrium, some solid NH4HS remains in the container. Predict and explain each of the following. (a) The effect on the ...

*January 13, 2011*

**microeconomics**

1. Why might a profitable motel shut down in the long run if the land on which it is located becomes extremely valuable due to surrounding economic development? 1a. What kinds of costs are involved in making a decision to shut down?

*January 12, 2011*

**chem**

what are the normal freezing points and boiling points of the following solutions: a. 21.1g NaCl in 135mL of water b. 15.4g urea in 66.7 mL water?

*January 12, 2011*

**chem**

what are the normal freezing points and boiling points of the following solutions: a. 21.1g NaCl in 135mL of water b. 15.4g urea in 66.7 mL water?

*January 12, 2011*

**math**

A dice is 4cm in all sides. What if you enlarge it by 1/4. What will be the size of all its size in cm3??

*January 8, 2011*

**Science (Energy)**

Ok i have done 2 experiments (See below) the question i need help with is i need to explain the difference for the two combustions and i just don't know, please help me and thankyou for your help. The Combustion Of Marshmallows Aim To investigate how much energy is ...

*December 17, 2010*

**physics **

How much paraffin oil would be needed to heat the same volume of water? • Heat capacity of water = 4200 j kg-1 K-1 • Mass of 1 litre of water = 1kg • Heat value of paraffin = 45M J kg-1 • Density of paraffin = 800kg m -3 • 1 cubic centimetre (1cm3 = 10...

*December 15, 2010*

**Physics **

How long would it take a kettle with a 1kW heating element to heat 1 litre of water? Watts = Joules / second • Mass of 1 litre of water = 1kg • 1 kW = 1 k Joule / second or 1000 joules/ second • 1g of water needs 4.184J to raise the temperature by 1̊ c. &#...

*December 15, 2010*

**reading**

Tell me about the bokk Eragon

*December 14, 2010*

**Chemstry**

A 5.00 gram mixture of CaO and CaCO3 is heated strongly. After heating, the mixture has a mass of 4.00 grams. What % of the original mixture is CaCO3?

*December 13, 2010*

**Chemistry**

A 5.00 gram mixture of CaO and CaO3 is heated strongly. After heating, the mixture it has a mass of 4.00 grams. What % of the original mixture is CaCo3?

*December 9, 2010*

**science**

can anyone give me 10 examples or energy interconversions and how they work please thankyou.

*December 5, 2010*

**science**

can anyone give me examples of energy intercoversions please

*December 5, 2010*

**math**

5-16/3=

*December 2, 2010*

**Math-3rd grade**

Round to estimate the sum of all the numbers in 14.

*December 1, 2010*

**4th grade**

$10

*December 1, 2010*