Friday
December 9, 2016

# Posts by Lisa

Total # Posts: 3,394

Chemistry
Write balanced complete ionic equation for HC2H3O2(aq) + K2CO3(aq)-----> H2O(l)+CO2(g)+KC2H3O2(aq) I put 2H+(aq)+2C2H3O2-2(aq)2K+(ag)+CO3-2(aq)------>H2O(l)+CO2(g)+2K+(aq)+C2H3O2-2(aq) and said it was wrong, but I got this part right. 2H+(aq)+CO3 2-(aq)----->H2O(l)+...
October 29, 2010

Calc
The area of a circular sinkhole increases at a rate of 420 square yards per day. How fast is the radius of the sinkhole growing when its radius is 50 yards?
October 28, 2010

algebra
PAM AND PAT HAVE \$20 ALTOGETHER PAM HAS \$4 MORE THAN PAT HOW MUCH MONEY DOES PAM HAS\$
October 28, 2010

Math
find values for r and t such that the inequality r < S < t best describes s, the length of the third sides of a triangle for which the lengths of the other two sides are given. 11. 2 and 4 thanks for the help !
October 27, 2010

geometry
find values for r and t such that the inequality r < S < t best describes s, the length of the third sides of a triangle for which the lengths of the other two sides are given. 11. 2 and 4 thanks for the help !
October 27, 2010

science
the carrying capacity for a population is estimated at 500. the population size is currently 400 and r max is 0.01. what is dN/df?
October 27, 2010

Science
if the large piston of a hydraulic press has an area of 60"(squared), what will be the total force upon it if a pressure of 15 psi is produced by the small piston?
October 26, 2010

Science
assume the pressure is kept constant if the volume of a gas quadruples, how does the absolute temperature change?
October 26, 2010

Science
the small cylinder of a hydraulic press has an area of 2"(squared). If a force of 10# is applied to the small piston, how much is the pressure within the larger cylinder increased, according to pascal's principle.
October 26, 2010

Chem
A 11.9-g sample of a gas has a volume of 5.25L at 30 degrees celsius and 762mm Hg. If 2.4g of the same gas is added to this constant 5.25-L volume and the temperature raised to 64 degrees celsius, what is the new gas pressure?
October 26, 2010

Physics
An object of mass 1.25 kg on a flat surface has two forces acting on it, F1 and F2 in the horizantal direction. F1 acts in the positive direction, F2 acts in the negative direction. The magnitude of F1 is 26.75 N. The object moves strictly along the horizontal x-axis, which we...
October 26, 2010

Chemistry
i don't understand the question though.
October 25, 2010

Chemistry
What incorrect information is given by the formula MgOH2 instead of the correct formula, Mg(OH)2 ?
October 25, 2010

Physics
suppose that the net external force exerted on the car is 350 N parallel to the ground, and the mass of the car is 1800 kg. What is its acceleration?
October 24, 2010

Physics
suppose that the net external force exerted on the car is 350 N parallel to the ground, and the mass of the car is 1800 kg. What is its acceleration?
October 24, 2010

preap physics
velocity = 0 m/s acceleration = 9.8 m/s^2
October 24, 2010

medical law and ethics
You are a health care professional working in a large office. Your administrator has asked you to prepare a poster summarizing the public duties of the physician as specified by law. The poster will be set up in the waiting room and will have a heading "We commit to these...
October 23, 2010

Physics
A force F=180 N pulls a crate at a 60 degree angle on a rough surface. The weight of the crate is 296 N and the friction force between the crate and the surface is 90 N. What state of motion might the crate be in?
October 23, 2010

Physics
Suppose that the coefficient of kinetic friction of the rubber of a car tire and the street is Uk = 0.8. What is the deceleration of the car on a flat street if the driver brakes sharply, so all the wheels are locked and skidding?
October 23, 2010

Physics
A brick of mass 1.0 kg slides down an ice roof inclined at 30 degrees with respect to the horizantal. If the brick starts from rest, how fast is it moving when it reaches the edge of the roof 0.90s later? Ignore friction
October 23, 2010

Statistics
The standard deviation of GPAs (grade point averages) of all male students at a college is .35 and the standard deviation of GPAs of all female students at the same college is .34. Suppose we take one sample of 40 male students and another sample of 50 female students from ...
October 22, 2010

Chemistry
1. When a potassium atom reacts with a bromine atom, the bromine atom will a) lose 1 electron and form a positive ion b) lose 2 electrons and form a positive ion c) gain 1 electron and form a negative ion d) gain 2 electrons and form a negative ion I know its either C/D but im...
October 21, 2010

chemistry
How much of a 100mM solution do I need to add to a 2.5mM solution to make a solution with a final concentration of 10nM? Is there a formula for this? Please HELP!
October 21, 2010

Orientalism
I do not understand what Orientalism has to do with Arab and Muslim Americans. Can someone please explain
October 21, 2010

math
define standard form
October 19, 2010

probability
icrobes in a certain colony exposed to radiation have a 1/6 chance of being mutated. a. If ten microbes from the colony are sampled, what is the probability that at most 4 will be mutated? b. If microbe from the colony is examined one by one, what is the probability that the ...
October 19, 2010

Physics
Assume cathy has to drag her suitcase along the floor of the airport terminal by a rope. The rope makes a 40.0 degree angle with the horizantal. The suitcase has a mass of 36.0 kg and Cathy pulls on the rope with a force of 65.0 N. a) What is the magnitude of the normal force...
October 18, 2010

probability
Microbes in a certain colony exposed to radiation have a 1/6 chance of being mutated. a. If ten microbes from the colony are sampled, what is the probability that at most 4 will be mutated? b. If microbe from the colony is examined one by one, what is the probability that the ...
October 18, 2010

Physics
Assume cathy has to drag her suitcase along the floor of the airport terminal by a rope. The rope makes a 40.0 degree angle with the horizantal. The suitcase has a mass of 36.0 kg and Cathy pulls on the rope with a force of 65.0 N. a) What is the magnitude of the normal force ...
October 18, 2010

Chemistry
You receive two samples of a substance. After testing, it shows that one sample contains 88% oxygen by mass an 12% hydrogen. The second sample contains 94% oxygen and 6% hydrogen. Is it possible that the two samples are the same? Explain. thanks, I appreciate the help !
October 17, 2010

Chemistry
You receive two samples of a substance. After testing, it shows that one sample contains 88% oxygen by mass an 12% hydrogen. The second sample contains 94% oxygen and 6% hydrogen. Is it possible that the two samples are the same? Explain. thanks, I appreciate the help !
October 17, 2010

Organic Chemistry - Melting Point
You have an unknown with an observed melting point of 90-93°C. Is your unknown compound A with a reported melting point of 95.5-96°C or compound B with a reported melting point of 90.5-91°C? Explain.
October 17, 2010

Chemistry
NiF2(aq)+Fe2(SO4)3(aq) ==NiSO4 (aq) + FeF3 (s) balance each of the following chemical equations. Express your answer as a chemical equation. Identify all of the phases in your answer. Can help me refresh my memory ...
October 16, 2010

probability
A company's records indicate that on any given day, 1% of their day shift employees and 2% of the night shift employees will miss work. Sixty percent of the employees work the day shift. a. What percent of employees are absent on any given day? b. A randomly selected ...
October 16, 2010

probabilityv
A school's administrators are concerned about absenteeism at their school and the e ect it has on students' grades. The following data were compiled, based on a sample of students. Student's Absent Medium Absent Grade Infrequently Absent Frequently Low 1 9 8 ...
October 16, 2010

Chemistry
thank you
October 15, 2010

Chemistry
Nitric acid is a component of acid rain that forms when gaseous nitrogen dioxide pollutant reacts with gaseous oxygen and liquid water to form aqueous nitric acid. Write a balanced chemical equation for this reaction. Express your answer as a chemical equation. Identify all of...
October 15, 2010

Chemistry
and I finaly got #1 it is Al2O3
October 15, 2010

Chemistry
I finaly got #2 it is K2O
October 15, 2010

Chemistry
Write a formula for the ionic compound that forms between each of the following pairs of elements. 1. aluminum and oxygen Express your answer as a chemical formula. AlO and Al2O3 and Al2O3 the 2 was the bottom right cornor and I got this message Use subscripts to represent the...
October 15, 2010

Chemistry
thank you so much you are awesome. ;-)
October 15, 2010

Chemistry
whoops Write a formula for the ionic compound that forms between each of the following pairs of elements
October 15, 2010

Chemistry
zink and sulfur Express your answer as a chemical formula. I entered Zn+2,S-2 and it said this to me There is an error in your submission. Make sure you have formatted it properly.
October 15, 2010

Chemistry
i put 44.3x131.30=5.81659E3 that's the answer it got, so I put it in 3 significant figures. I guess I am really confuss
October 14, 2010

Chemistry
5.81 g is that right
October 14, 2010

Chemistry
What is the mass, in grams, of each of the following? 44.3 mol Xe
October 14, 2010

Chemistry
m= 4.90 g
October 14, 2010

Chemistry
3.57×10−2 mol Ba Express your answer using three significant figures
October 14, 2010

3rd grade math
8 times 493= 3944 using distributive property then solve with array showing the work
October 14, 2010

5th grade/ Math
Your Max (highest number) = 18 Your range is 13 so your minimum number in your set =5 You need the mean to = 12 so all twelve numbers in your set have to equal 144 so that the 12 individual numbers will have a mean of 12 (144/12=12). The mode = 7 - so 7 is going to occur more ...
October 14, 2010

Math
I have a few questions about T-Matrix. In excel, I am suppose to work with powered matrices to construct a weighted T matrix, using a scalar of .7. Does this mean I multiply each of the powered matrices by .7? Or do I power the powered matrices by .7? Or am I completely off ...
October 13, 2010

english - thesis statement
Based on the reading Wolf-Alice by Angela Carter I need to put together a thesis statement, regarding the development of self identity. Wolf-Alice is a feral child who lived with a pack of wolves. Group of nuns take her in to try to show her human ways (since she couldn't ...
October 13, 2010

statistics
Considering that a researcher can test at the <p = .05 (95%), p = .01 (99%), or p = .001 (99.9%) level for statistical significance, how do you use these three levels in relationship to evaluate risk to patients in implementing the decisions based on research findings?
October 12, 2010

Algebra
please show steps solve 9 - (9)squared > 10x - x
October 11, 2010

Algebra
-4 - 2n + 4n > 7 - 4
October 11, 2010

Algebra
Homework help please: algebra inequality 0.3 - 0.5n + 1 is greater than or equal to 0.4
October 11, 2010

Physics
A horse canters away from its trainer in a straight line, moving 120 m away in 11.0 s. It then turns abruptly and gallops halfway back in 4.9 s.
October 11, 2010

English
What would be good sentence for emerald?
October 11, 2010

English
I needed to create sentence containing the phrase "green with envy". I have got two sentences here, but I need help picking out the one that makes more sense. Emily’s new look made her friends green with envy. Emily’s friends became green with envy when ...
October 11, 2010

Science
Thank you Sra! This is for 7th grade science - so it looks as though dynamic condition is a state of constant moving until all parts are equal and static condition is motionless. Do you know if this correct?
October 11, 2010

Science
The state of cellular equilibrium is best described as a dynamic condition, not static. What does this mean?
October 11, 2010

American Democray
The president's role in foreign policy increased largely because: a Congress proved so inept in foreign affairs that the american people demanded a change b America became more of a world poer c of the need to coordinate national economic poicy and foreign policy, a task ...
October 10, 2010

Chemistry
What is the specific heat (in cal) of fat with a degree change from 25 degrees Celsius to 35 degrees celsius? Density of fat = 0.94 g/cm^3
October 7, 2010

Math
Betsy, a recent retiree, requires \$6,000 per year in extra income. She has \$60,000 to invest and can invest in B-rated bonds paying 13% per year or in a certificate of deposit (CD) paying 3% per year. How much money should be invested in each to realize exactly \$6,000 in ...
October 6, 2010

chem
Po-218 is an alpha emitter with a half-life of 3.0 minutes. If a sample contains 69 mg of Po-218, how many alpha emissions would occur in 6.0 minutes? the answer has to be _________a emmisions (which I have no idea what it means) and I use a chart thing with amount, #H-L, and ...
October 5, 2010

Chemistry
Draw the lowest energy conformation of 3-ethyl-2,4,4-trimethylheptane, depicting the C3-C4 bond on a sawhorse. How would i do this? i am so lost
October 5, 2010

geometry
fine the perimeter of ABCD = 46. AB = x+9, CD= 2x-7
October 4, 2010

math
what does equivalent mean?
October 4, 2010

8th grade math
I understand that part but I'm just not sure when the question asks me what VALUE will make the equation TRUE will it be x=-72? because I don't think that's what there asking me.
October 4, 2010

English composition
Music during slavery: A call to arms or a panacea?
October 3, 2010

chem
Write a partial decay series for Rn-220 undergoing the following sequential decays: á (alpha decay), á, â(beta decay), á. (Enter the mass number in the first raised box, the atomic number in the second lower box and the symbol of the element in the ...
September 30, 2010

Math
Im pretty sure you could use the pythagorean theorem a^2 + b^2 = c^2 just plug in the numbers you have and solve for c
September 30, 2010

spanish
Im not quite sure what your asking do you mean something like tus companeros de clase?
September 30, 2010

math
median=90 you find the median by putting all the numbers in order and finding the middle number
September 30, 2010

math
47 rounded to the ten's place is 50
September 30, 2010

chemistry
oops b and c should be b decay and in the directions its a,b,a,b
September 30, 2010

chemistry
Write a partial decay series for Po-214 undergoing the following sequential decays: á, â, á, â. Use e for an electron. Use the format +1 or -1 for charge. a)a decay b)â decay c)a decay d)â decay
September 30, 2010

chem
(b) If the natural abundance of Ag-107 is 51.84%, what is the natural abundance of Ag-109? 48.16 % (c) If the mass of Ag-107 is 106.905, what is the mass of Ag-109? 108.9 amu so i got the answers correct but kinda forgot how because it took me a while so do you think you could...
September 29, 2010

11th grade
sound travels at 350 m/s in warm air. "If you hear the echo in 10 seconds, how far away is the reflecting surface?
September 28, 2010

science, density
The density of sea water is slightly higher than that of fresh water. The higher density is due to the fact that sea water contains salts such as sodium chloride and magnesium chloride. Suppose you have a container that holds 5.00 kg of fresh water, which has a density of 1.00...
September 28, 2010

Math
how do I solve this problem. In 1920 the record for a certain race was 445.7 sec. In 1970, it was 44.2 sec. Let R(t) = the record in the race and t = the number of years since 1920. a) Find a linear function that fits the data R(t) = b) What is the predicted record for 2003? c...
September 26, 2010

The Young Child and the Environment
When a child not only throws a ball farther than she had previously, but also changes the way the throws the ball, the change is called A. Cumulative B. Multifactoral C. Quantitative D. Qualitative
September 23, 2010

Chemistry
A sample of gas occupies 3.00 L at 760 torr. Calculate the volume it will occupy at 1.45 atm and the same temperature?
September 23, 2010

Chemistry
A balloon filled with helium has a volume of 1.oo x 10^3 L at 20 degrees c. What will be the balloons volume at 30 degrees c, if the pressure surrounding the balloon remains constant?
September 23, 2010

sport
If air resistance is negligible what would the flight path of a shot from the moment of release to the moment immediately prior to landing look like using newtons 3rd law of motion?
September 22, 2010

sport
Can you name and explain 3 factors (excluding air effects ) which should be utilised by a shot putter to optimise the distance thrown using newtons trird law of motion
September 22, 2010

Sport
Why is the flight path of a shot putt different to that of a badminton shuttle using newtons third law of motion?
September 22, 2010

sport
How do i explain the effect of air resistance on the flight of two badminton shuttles, the first of which has been struck hard (with a greater application of force) and the second which has ben struck gently?
September 22, 2010

Sport
How do I explain using Newtons 3rd Law the nature of the reaction force which provides impulsion for a cyclist?
September 22, 2010

Physics
Bobpursley -- I do not understand. The answer was 5.7 s and I have no idea what equation was used to get that.
September 21, 2010

Physics
Can someone help me to understand how to work out this problem? The pilot of an airplane traveling 240 km/h wants to drop supplies to flood victims isolated on a patch of land 160 m below. The supplies should be dropped how many seconds before the plane is directly overhead?
September 21, 2010

5th grade
What is subject and verb of this sentence...The rest of story was never told.
September 20, 2010

english
What is the subject a d verb of this sentence...The rest of the story was never told.
September 20, 2010

math
Three different pairs of numbers that add together to get 1
September 20, 2010

molal
the freezing point of ethanol (C2H5OH) is -114.6C. the molal freezing point depression constant for ethanol is 2.00C/m. what is the freezing point (C) of a solution prepared by dissolving 50.0 g of glycerin (C3H8O3, A nonelectrolyte) in 200 g of ethanol. i tried to solve it on...
September 16, 2010

molal (again)
im not sure about the last step tho... i know the final answer is -120.0 but im not sure how to get to that...
September 15, 2010

molal (again)
i tried to solve it on my own but im confused about the last part, this i what i have so far.. moles of glycerin= 50.0/92.10=0.54 molality=0.54/0.200=2.7 is that right? im a little confused about the numbers im supposed to use for step 3... this was the question: the freezing ...
September 15, 2010

Chemistry
a car is traveling at a rate of 41.2 megameters/hr. what is the rate in cm/s?
September 15, 2010

Physics
An airplane flies 200 km due west from city A to city B and then 345 km in the direction of 32.0° north of west from city B to city C In straight-line distance, how far is city C from city A?
September 14, 2010