# Posts by kelly

Total # Posts: 1,763

**Chemistry**

Calculate the final pressure on the addition of 2.0 g He(g) to a vessel of 10.0 L fixed volume already containing O2(g) at 25°C and 740 mm Hg

**Learning through Play**

One of the parents in your school says, “I really enjoyed coming to Parents’ Night last week and seeing all the things the children are doing. I was particularly interested in your comments about the materials which enhance cognitive abilities. Why is it so much ...

**Calc- Trig Substitution**

integral of dx/square root(x^2-64) My answer is: ln (x/8 + square root(x^2-64)/8) +c is this right?

**physics**

A model of a helicopter rotor has four blades, each 3.40 {m} in length from the central shaft to the tip of the blade. The model is rotated in a wind tunnel at 580 {rev/min}. What is the radial acceleration of the blade tip, expressed as a multiple of the acceleration g due to...

**chemistry**

how many times a proton is heavier than an electron

**Math**

Write an addition problem in which, when the addends are rounded to the nearest ten, the sum is 90. Then explain how you use estimation to solve the problem.

**physics**

A skydiver jumps out of a hovering helicopter, so there is no forward velocity. Use this information to answer questions 1 to 9. Ignore wind resistance for this exercise. What is the skydiver's acceleration?

**functions 12**

after i solve for x then that is my answer? so x=1/3,-1

**functions 12**

so would it be (3sinx-1)(4sinx+4)=0?

**functions 12**

solve 12cos^2X=8+13sinX between the window of -360 ¡Ü x ¡Ü 360

**chemistry**

Why are hydrogen ions NEVER found in an aqueous solution?

**geometry**

the top of a giant slide is 30 ft off the ground. the slide rises at a 30 degree angle. to the nearst whole foot, what is the distance down the slide?

**Science**

I have a few questions if someone could please help with them: Which of the following is true: A.Relative dating tells us how long ago something existed B.Disconformities are less common but usually far more conspicuous because the strata on either side are essentially C....

**Chemistry**

A solution of .12 mol/L of phosphoric acid completely neutralizes .20L of a solution of sodium hydroxide with.a concentration of .15mol/L What is the neutralizing volume of the phosphoric acid?

**ethics**

I am doing a presentation on biomedical issues- abortion. My part is what issues involve problems with consent. Can you help please

**Earth Science**

Which of the following is true: -Relative dating tells us how long ago something existed -Disconformities are less common but usually far more conspicuous because the strata on either side are essentially -Estimates indicate that the North American continent is being lowered ...

**Maths lit,geography,life science,pysical science**

Help us plz

**Chemistry**

Are these right? I didn't know some of them. 1. AgNO3 Soluble, rule 3 2. Ag2SO4 Insoluble, rule 4 3. HgCl2 Insoluble, rule 2 4. BaSO4 Insoluble, rule 4 5. CaCl2 Soluble, rule 2 6. NH4OH ? 7. PbCl4 Insoluble, rule 2 8. Mg(C2H3O2)2 Soluble, rule 3 9. HgCl Soluble, rule 2 10...

**Chemistry**

how do you determine the solubility of the following salts: 1. AgNO3 2. Ag2SO4 3. HgCl2 4. BaSO4 5. CaCl2 6. NH4OH 7. PbCl4 8. Mg(C2H3O2)2 9. HgCl 10. CaF2 11. CuO 12. AgI 13. Al(OH)3 14. Fe2(CO3)3 15. CrPO4 16. K2S

**Chemistry**

what are the rules used to determine the solubility of salt?

**Honors Chemistry**

1. What is the pH of a solution whose [H3O+] is 1 X 10^ -5 M? 2. What is the [H3O+] concentration of a solution with a pH of 9? 3. What is the pH of a solution whose [H3O+] concentration is 3 X 10^-3 M? 4. What is the pH of a solution with a [H3O+] concentration of 1 X 10^ -12...

**Shurley English**

What are Single Quotes and when do you use them?

**Phsyics**

A cannonball is fired into the air with a speed of 42 m/s from a height of 28 m, with what speed does the cannonball hit the ground?

**physics**

An unmarked police car traveling a constant 95km/h is passed by a speeder traveling 14km/h .Precisely 2.50s after the speeder passes, the police officer steps on the accelerator; if the police car's acceleration is 2.30m/s^2 , how much time passes before the police car ...

**Science**

The object distance for a convex lens is 15.0 cm, and the image distance is 5.0 cm. The height of the object is 9.0 cm. What is the height of the image?

**Math**

a.16 inches by 16 inches b.15 inches by 15 inches c.19 inches by 19 inches d.17 inches by 17 inches

**Math**

Janna is creating a multi-tiered cupcake display for a party. She plans on having 16 cupcakes on each tier. -There is a 1-inch space between all cupcakes. -The cupcakes have a uniform width [diameter] of 3 inches. -Each tier will display the cupcakes in either 2 rows of 8, or ...

**physics ! HELP PLEASE !!!!1**

what are the methods of computing the veolicty of a particle in one- dimensona motion from a graph ?

**physcis ! HELP !!!!**

which of collowing situations describe a particle that might have a non-zero velocity? canbe more than one A) a particle that has a constant position as a function of time B) a particle that has its position changing as a fnction of time c)when you graph the particle's ...

**physics**

which of collowing situations describe a particle that might have a non-zero velocity? canbe more than one A) a particle that has a constant position as a function of time B) a particle that has its position changing as a fnction of time c)when you graph the particle's ...

**physics**

what are the methods of computing the veolicty of a particle in one- dimensona motion from a graph ?

**World History**

because

**algebra**

Using the formula for BMI: B = 703(w)/ h² When the weight is 100 lbs and the BMI is 20, how do I figure out the persons height?

**physics**

An automobile traveling 95 overtakes a 1.10--long train traveling in the same direction on a track parallel to the road. Q1: If the train's speed is 75 , how long does it take the car to pass it Q2:How far will the car have traveled in this time? Q3:What is the time if the...

**physics**

An automobile traveling 95 overtakes a 1.10--long train traveling in the same direction on a track parallel to the road. Q1: If the train's speed is 75 , how long does it take the car to pass it Q2:How far will the car have traveled in this time? Q3:What is the time if the...

**physics**

i got answers to some of the questions Q1: 3.3 mins Q2: ?km <- still need help with Q3:23.3 Q4:?km still need help with

**physics**

An automobile traveling 95 overtakes a 1.10--long train traveling in the same direction on a track parallel to the road. Q1: If the train's speed is 75 , how long does it take the car to pass it Q2:How far will the car have traveled in this time? Q3:What is the time if the...

**geometry**

Bow66, Thank you so much, you are correct!!!!! 100%!!!

**Science**

Identify 5 different materials that you encounter or use on a daily basis, and identify a mineral that is mined to supply each of those materials.

**Math**

Thank you for the help :)

**Math**

The Longhorns punted the ball from the 5-yard line. The punt was caught at the 41-yard line and returned to the 19-yard line. The ball did not cross the 50-yard line. What was the net yardage on the play?

**Physics Help!!!**

its wrong :/

**Physics Help!!!**

One of the 79.0 -long strings of an ordinary guitar is tuned to produce the note (frequency 245 ) when vibrating in its fundamental mode. Part A- If the tension in this string is increased by 3.2 , what will be the new fundamental frequency of the string? F= ? Hz i understood ...

**Physics Help!!!**

One of the 79.0 -long strings of an ordinary guitar is tuned to produce the note (frequency 245 ) when vibrating in its fundamental mode. Part A- If the tension in this string is increased by 3.2 , what will be the new fundamental frequency of the string? F= ? Hz i understood ...

**physics**

Two point charges are fixed on the y axis: a negative point charge q1 = -23 µC at y1 = +0.23 m and a positive point charge q2 at y2 = +0.33 m. A third point charge q = +7.8 µC is fixed at the origin. The net electrostatic force exerted on the charge q by the other ...

**math**

A cylinder shaped sculpture is 24 meters high with a diameter of 6.8 meters. An artist plans to spray paint the entire surface with silver paint. If 1 can of spray paint covers 50 square meters, how many cans does the artist need to paint the sculpture?

**Chemistry III**

I'm sorry thank you so much for all your help but I seem to be getting the wrong answer for part c and I don't understand how to get the individual ion's moles for part b. I have the correct volume of 0.00197L. For part c I am doing as you say and I get a pOH of 5....

**Chemistry III**

Assume you dissolve 0.240 g of the weak acid benzoic acid, C6H5CO2H, in enough water to make 1.16 102 mL of solution and then titrate the solution with 0.153 M NaOH. C6H5CO2H(aq) + OH -(aq) C6H5CO2-(aq) + H2O(l) (a) What was the pH of the original benzoic acid solution? (b) ...

**Chemistry II**

You place 1.234 g of solid Ca(OH)2 in 1.00 L of pure water at 25°C and it partially dissolves. The pH of the solution is 12.40. Estimate the Ksp for Ca(OH)2.

**Chemistry**

A 20.2 mL sample of a weak monoprotic acid, HX, requires 50.0 mL of 0.060 M NaOH to reach the equivalence point. After the addition of 30.0 mL of NaOH, the pH is 5.50. What is the Ka of HX?

**arithmetic**

The pet shop owner told jean to fill the new fish tank 3/4 full of water.Jean filled the tank 9/12 full.What fraction of the tank does she still need to fill?

**statistics**

A student is interested in whether students who study with music playing devote as much attention to their studies as do students who study under quiet conditions (he believes that studying under quiet conditions leads to better attention). he randomly assigns participants to ...

**CHEMISTRY HELP NEEDED!!**

Given info: Reaction: 3A+2B--->2C+D {A] (mol/L) 1.0 ×10^-2 1.0 ×10^−2 2.0 ×10^−2 2.0 ×10^−2 3.0 ×10^−2 [B] (mol/L) 1.0 3.0 3.0 1.0 3.0 Rate of appearance of C (mol/L-hr) 0.30×10^−6 8.10×10^−6 3....

**Chemistry**

Given info: A] (mol/L) [B] (mol/L) Rate of appearance of C (mol/L-hr) 1.0 ×10^-2 1.0 0.30×10^−6 1.0 ×10^−2 3.0 8.10×10^−6 2.0 ×10^−2 3.0 3.24×10^−5 2.0 ×10^−2 1.0 1.20×10^−6 3.0 ×10...

**Chemistry**

calculate the specific rate constant between substances A and B has been found to given data 3A + 2B ---> 2C + D

**Chemistry**

calculate the specific rate constant A] (mol/L) [B] (mol/L) Rate of appearance of C (mol/L-hr) 1.0 ×10^-2 1.0 0.30×10^−6 1.0 ×10^−2 3.0 8.10×10^−6 2.0 ×10^−2 3.0 3.24×10^−5 2.0 ×10^−2 1.0 1.20×...

**Chemistry**

calculate the specific rate constant A] (mol/L) [B] (mol/L) Rate of appearance of C (mol/L-hr) 1.0 ×10^-2 1.0 0.30×10^−6 1.0 ×10^−2 3.0 8.10×10^−6 2.0 ×10^−2 3.0 3.24×10^−5 2.0 ×10^−2 1.0 1.20×...

**Chemistry**

collect the specific rate constant....

**Chemistry**

calculate the specific rate constant A] (mol/L) [B] (mol/L) Rate of appearance of C (mol/L-hr) 1.0 ×10^-2 1.0 0.30×10^−6 1.0 ×10^−2 3.0 8.10×10^−6 2.0 ×10^−2 3.0 3.24×10^−5 2.0 ×10^−2 1.0 1.20×...

**Chemistry**

calculate the specific rate constant A] (mol/L) [B] (mol/L) Rate of appearance of C (mol/L-hr) 1.0 ×10^-2 1.0 0.30×10^−6 1.0 ×10^−2 3.0 8.10×10^−6 2.0 ×10^−2 3.0 3.24×10^−5 2.0 ×10^−2 1.0 1.20×...

**Chemistry**

How would you analyze a solution known to contain Hg22+ and Cu2+?

**PHYSICS**

Determine the value for the acceleration due to gravity at the surface of the planet Mars, given the following data: Mass of Mars = 6 .42 x 10^23 kg Radius of Mars = 3.37 x 10^6 m Thanks!

**CHEMISTRY**

Ppcl3 6.78 torr Pcl2 26.4 Ppcl5 224

**Math**

x^2+1/4x+_?__

**physics**

115.19

**Physics**

Take the radius of the earth's orbit to be 1.5 x 1011 m. a. Using a year to be 365 days, find the speed of the earth as it moves around the sun. __m/s b. Convert this speed to miles/hour (show your conversion factor in your written backup). __miles/hour

**Physics**

Take the radius of the earth at the equator to be 6380 km a. Find the speed the speed of an object at the equator due to the earth's rotation. ___m/s b. Convert this speed to miles/hour (show your conversion factor in your written backup). __miles/hour

**Stats**

Explain how to calculate margin of error. What effect does increasing your sample size have on the margin of error? What effect does it have on the confidence level? What effect does it have on the confidence interval?

**algebra**

a bag contains only nickels and dimes. there are exactly 18 coins in the bag. the amount of money in the bag is $1.25. let x represent the number of nickels in the bag. let y represent the number of dimes in the bag. 1. write a system of equations that correctly models this ...

**algebra**

you are planning a cookout. you figure that you will need at least 5 packages of hot dogs and hamburgers in total. a package of hot hods costs $1.90 and a package of hamburgers costs $5.20. you can spend a maximum of $20 in total on the hot dogs and hamburgers. Identify two ...

**algebra**

find each probability if you pick a card, do not replace it, then pick a second 3 white cards 5 black cards and you pick black, then white

**Stats**

Explain how to calculate margin of error. What effect does increasing your sample size have on the margin of error? What effect does it have on the confidence level? What effect does it have on the confidence interval?

**Stats**

Explain how to calculate margin of error. What effect does increasing your sample size have on the margin of error? What effect does it have on the confidence level? What effect does it have on the confidence interval?

**Math**

1.5x+4y=8 x+y=7 Please help me solve this system of equation and show your work.

**chemistry**

How many liters of 0.101 m NaCl contains 1.70 mol of this salt? Assume this solvent is H2O. Answer in units of L I do not understand what i am looking for or how to solve for it. Steps would be appreciated.

**algebra**

A DVD player's laser reader helps to "read" the information on the DVD. A particular laser reader measures 0.56 micron thick. does this fall with the required standards if a company uses |t - 0.03 | <= 0.525 for determining the part to be acceptable?

**algebra**

A typical DVD can store between 137.9 and 142.1 minutes of data before it is considered full. write an absolute value inequality describing the minutes of data (w) a full DVD will hold.

**algebra**

A bump on a DVD needs to be between 0.45 and 0.55 micron wide and 0.95 and 0.99 micron high. write two absolute value inequalities describing the width (x) and height (y) of the bump.

**biology**

suggest a reason for the failure of some of the molecules to diffuse through the semipermeable membrane.

**Chemistry**

.28C = 30C * x/.2kg x = .001867 moles S .001867 moles S = .48g S/x x = 8.0177 molecular formula for S Is this correct?

**Chemistry**

If 0.48 g of sulfur are added to 200 g of carbon tetracholoride, and the freezing point of the carbon tetrachloride (Kf=30 degrees C/m) is depressed by 0.28 degrees C, what is the molar mass and molecular formula of the sulfur? .48g * 1mol/32.07g= .01497 mol S .01497/.2 kg = ....

**Chemistry**

.48g * 1mol/32.07g= .01497 mol S .01497/.2 kg = .07485 molality 273.28K= i * 293K * .07485 i = .08 ??

**Chemistry**

thank you :)

**Chemistry**

If 0.48 g of sulfur are added to 200 g of carbon tetracholoride, and the freezing point of the carbon tetrachloride (Kf=30 degrees C/m) is depressed by 0.28 degrees C, what is the molar mass and molecular formula of the sulfur?

**math**

Assume that you randomly select 8 cards from a deck of 52. What is the probability that all of the cards selected are hearts?

**Math**

A group of students who are selecting 2 of their group at random to give a report, but assume that there are 5 males and 3 females. What is the probability that 2 females are selected? 2 males?

**Math**

Assume that you select 2 coins at random from 5 coins: 3 dimes and 2 quarters. What is the probability that all of the coins selected are dimes?

**sociology**

Social capital refers to the collective value of all "social networks" [who people know] and the inclinations that arise from these networks to do things for each other ["norms of reciprocity"].

**sociology**

cultural capital is defined as “forms of knowledge, both tangible and intangible, that have value in a given society in relation to status and power Cultural capital defines how people (human) engage each other (social) and their resources (economic).

**sociology**

what are some examples of social and cultural capital that young children experience

**Physics**

A 1.7 cm thick bar of soap is floating in water, with 1.1 cm of the bar underwater. Bath oil with a density of 890.0 kg/m3 is added and floats on top of the water. How high on the side of the bar will the oil reach when the soap is floating in only the oil.

**Physics**

A 1.7 cm thick bar of soap is floating in water, with 1.1 cm of the bar underwater. Bath oil with a density of 890.0 kg/m3 is added and floats on top of the water. How high on the side of the bar will the oil reach when the soap is floating in only the oil.

**math**

45 1/5 x 3/4 =

**biology**

the importance of these organic compounds ( carbohydrates, proteinds, lipids) in the cells and tissues of living things

**Physics**

A ball is thrown upward from the top of a 50.0 m tall building. The ball's initial speed is 12.0 m/s. At the same instant, a person is running on the ground at a distance of 44.0 m from the building. What must be the average speed of the person if he is to catch the ball ...

**English**

yes i read it but i dnt understand it

**launguge arts**

I need to un scramble these words and make new ones help eioubdhrs

**bio101**

2. Find a media piece—article, video, presentation, song, or other—that recognizes the fundamental concepts of chemistry in biology. Include the link or reference citation for the piece and describe how it helped you better understand how fundamental concepts of ...

**math**

Joe and Bob manufacture bikes. Joe can make 12 bikes in 8 hours while Bob can make 12 bikes in 6 hours. Working together how many hours will it take them to make 12 bikes? Please explain showing steps so I can learn it. I don't just need the answer. Thanks! PS I originally...

**math**

Joe and Bob manufacture bikes. Joe can make 12 bikes in 8 hours while Bob can make 6 bikes in 12 hours. Working together how many hours will it take them to make 12 bikes? Please explain showing steps so I can learn it. I don't just need the answer. Thanks!