# Posts by Q

Total # Posts: 92

Math 3rd
Tim tracked the change in outside temperature one afternoon. He recorded a temp of 85.4 f at noon. The Temperature then rose 3.85 f over the next 4 hours. At 5:00 Tim recorded the temperature of 89.25 f how did the temperature change betwn 4:00pm and 5:00pm? My cousin got the ...

math
simplify (8*10^7)(7*10^4) i think it's 5.6*10^10 simplify (3*10^6)(8*10^-4) i think it's 2.4*10^3 Astronomers measure large distances in light-years. One light-year 5.88*10^12 mi Star is 9.8*10^1 light years from Earth in scientific notation how many miles I think it&#...

Algebra
110 student went to the lake for a boat ride. there were 8 both (each would safely hold the same number of student), and all but 14 students could go for a ride. those remaining 14 students had to wait until first students finished their ride before they could go. how many ...

Math
water flows over a dam at a rate of 500 gallons per minute write a function rule relating the amount of water a that flow over the dam to the number of minutes m that have passed what are the initial value and rate of change

Algebra 1
idk

AP Chemistry
Calculate ΔHrxn for the following reaction: C(s)+H2O(g)→CO(g)+H2(g) Use the following reactions and given ΔH values: C(s)+O2(g)→CO2(g), ΔH= -393.5 kJ 2CO(g)+O2(g)→2CO2(g), ΔH= -566.0 kJ 2H2(g)+O2(g)→2H2O(g), ΔH= -483.6 kJ

MATH HELP
no its wrong

Probability
Is that the right answer for c?

English.
Thanks?

English.
Please check my answers? Letter of Recommendation Mary O'Dell PLTW Program Willow High School 1400 Old Tamah Road Irmo, SC 29067 April 11, 2007 Subject: Letter of Recommendation for Mr. Chris Moses To Whom It May Concern: Chris studied under my supervision as a student ...

Algebra II
From 1990-1994 the mail order sales of health products can be modeled by S= 10t^3+115t^2+25t+2505 where S is the sales (in millions) and t the number of years since 1990. In what year were about \$3885 million health products sold.

SCGC
ass

Calculus
Linda has \$9000 to invest. She invested x dollars in an account that earned 3% simple interest and the remainder of the money in an account that earned 2.6% simple interest. In one year, both accounts together earned \$250 interest. How much was invested in each account?

AP Chemistry
I got it! The initial concentration of CN- would be 0.065 M rather than 0 M.

AP Chemistry
The Ksp of Ni(CN)2 is 3.0 × 10−23. What is the molar solubility of Ni(CN)2 in a 0.065 M KCN solution? Answer in units of mol/L. I found that the normal molar solubility is 1.957x10^-8, but I don't know how the KCN solution affects it. Sig figs aren't ...

chemistry
Calculate the amount of heat absorbed when 58 g of steam at 117◦C are completely converted to ice at −32.5◦C. Specific Heat: H2O(s) = 2.09 J/g◦C H2O(l) = 4.18 J/g◦C H2O(g) = 2.03 J/g◦C Heat of Fusion = 334 J/g Heat of Vaporization = 2260 J/g...

math
a football player attempts a field goal from a distance of 52 yards. The ball reaches a maxium height of 9 yrds and lands 8 yards behind the uprights. If the uprights are 3 yards high. algebraically determine if the field goal was successful

chemistry
i need help solving this Benzoic acid is a weak, monoprotic acid (Ka = 6.3 × 10−5). Calculate the pH and the percent dissociation of each of the following solutions of benzoic acid. Then use Le Châtelier’s principle to explain the trend in percent ...

chemistry
How would you do this question: A student dissolved 5.0 g of vitamin C in 250 mL of water. The molar mass of ascorbic acid is 176 g/mol, and its Ka is 8.0 × 10−5. Calculate the pH of the solution. Note: Abbreviate the formula of ascorbic acid to HAsc.

Maths Probability
Anyone got right answer for c = ?

probability
Let N be the numbers of passengers that show up. So p=0.9 and E[N]=0.9n and σ=(n*0.1*0.9)^1/2=0.3*n^1/2. Using Moivre-Laplace we have P(N≥300.5)≈0.01 Next you should use CLT, solving quadratic equation and find value of n

Probability
Jacob, can you explain how did you get these answers? I want understand this problem

Calculus
Find a positive number such that the sum of the square of the number and its reciprocal is a minimum.

For an outdoor concert, a ticket price of \$30 typically attracts 5000 people. For each \$1 increase in the ticket price, 100 fewer people will attend. The revenue, R, is the product of the number of people attending and the price per ticket. a) Let x represent the number of \$1 ...

Calculus
There are 50 apple trees in an orchard, and each tree produces an average of 200 apples each year. For each additional tree planted within the orchard, the average number of apples produced drops by 5. What is the optimal number of trees to plant in the orchard? I mostly need ...

A rectangular piece of paper with perimeter 100 cm is to be rolled to form a cylindrical tube. Find the dimensions of the paper that will produce a tube with maximum volume. I have made it up to getting an equation for V(w).

Math
2x(√3x^2)*2√x how would you simplify this?

Math
2x√3x*2√x i was wondering how to simplify this

AP Chemistry
The Ksp of Ni(CN)2 is 3.0 × 10−23. What is the molar solubility of Ni(CN)2 in a 0.065 M KCN solution? Answer in units of mol/L. I found that the normal molar solubility is 1.957x10^-8, but I don't know how the KCN solution affects it. Sig figs aren't ...

Complex Math
Compute all possible values of e^i

Calculus
Evaluate the surface integral. the double integral of (x^2 + y^2 + z^2)dS over Region S. S is the part of the cylinder that lies between the planes z = 0 and z = 5, together with its top and bottom disks Can anyone help?

multivariable calculus
Studying for a test, and saw this: Find the center of mass of the hemisphere x^2 + y^2 + z^2 = a^2; z>=0 if it has constant density. Any ideas?

physics
In attempting to jump up a waterfall, a salmon leaves the water 2.0 m from the base of the waterfall. With what minimum speed must it leave the water in order just to make it up a waterfall 1.6 m high?

Improving writing assignment
I have noticed that in the last three months, the performance and qualities of work has been compact due to workloads unbalanced, since Jessica Hilo our executive manager has been on medical leave for last four months. Her responsibilities have been shared between Ralph and ...

english
What is the author referring to in this reading passage? Thus early had that one guest,--the only guest who is certain, at one time or another, to find his way into every human dwelling, --thus early had _______ stepped across the threshold of the House of the Seven Gables!

physical
David's clock ticks once for every two of Phil's clock ticks. How fast is Phil moving by David?

physical
Franky claims he has a mass of 65kg. He is sitting on a spherical bouy that oats just barely submerged under water. When he gets o it rises halfway out of the water. What must the radius R in centimeters of the sphere be for him to be telling the truth?

PHYS
You throw a bowling ball o the empire state building(381m high) 10m/s down- ward. How long does it take to get to the bottom?

algebra
If Jenny's car uses less gas per mile driven than Sandra's truck, how does the graph representing the rate of change of Sandra's truck compare to the graph representing the rate of change of Jenny's car?

math
What?

Quick Math Question
okay thx

Quick Math Question
How do I add time? If a person worked 4 1/2 hours on Monday, 4 1/2 hours on Tuesday and 2 hours on Wednesday, does that add up to 12 hours? If not, how much more time would the person need to work the next day to equal 12 hours?

Soc Stud
so its c

Chemistry

Chemistry
Ghh

engineering mechanics
A person A is trying to keep his balance while on a sled B that is sliding down an icy incline. Let mA = 78kg and mB = 25 kg be the masses of A and B, respectively. In addition, let the static and kinetic friction coefficients between A and B be μs = 0.4 and μk = 0....

Chemistry
The phase fraction is calculated using the 'Lever Rule'. I can't figure out how to do it, but it involves using this formula- X = (c-b)/(a-b) Where a, b, and c are distances between x-coordinates at various phase boundaries. But the phase diagram in this question ...

Physics
A refrigerator does 18kJ of work while moving 115 kJ of thermal enegy from inside the refrigerator. What is its coefficient of performance?

Physics
A refrigerator has a coefficient of performance of 4.0. When removing 2.4x10^4 J from inside the refrigerator, how much energy is sent into the environment?

Math
For a class C corporation in Louisiana, the amount of state income tax S is deductible on the federal return and the amount of federal income tax F is deductible on the state return. With \$200,000 taxable income and a 30% federal tax rate, the federal tax is 0.30(200,000 - S...

math
123145

Chemistry
Consider this equilibrium N2(g) + H2(g) <==> NH3(g) +94 kJ The equilibrium law exoression for the balanced chemical equationwould be A. [N2][H2]/[NH3] B. [NH3]/[H2][N2] C. [NH3]2/[H2][N2] D. [NH3]2/[H2]3[N2] E. 2[NH3]2/3[H2]3[N2]

Chemistry
which of the following statement are true for all electric cells? I. electrons flow from the anode to the cathode II. reduction occurs at the anode III. oxidation occurs at the cathode IV. oxidation occurs at the anode V. reduction occurs at the cathode A. I,IV and V B. I,II ...

maths
if 3x + 8 =20 - 3x, what is x

geometry
if 3x + 8 =20 - 3x, what is x

math
You receive an invoice for \$565.00 with terms 3/10, net 30. If you pay it immediately, how much will you pay?

american government
What is the difference between civil liberties and natural rights?

Math
a.Set table as x,chair as y 90x+40y<or=1000 b.just plug in and try c.so y=6x substitute 6x for y you get 90x+240x<=1000 so x<=100/33 greatest one is 3 for table,18 for chair

Physics
Question, wouldn't it be 720 years? Because 10 years = 1 century. So .001ms/day ( 365days/yr) * 720 years * 1s/1000ms * 1hr/3600s

math
6 minutes

math
5x-3y=11 4x-7y=18

accounting
Derm Travel Agency accepted a four-month, 9% interest rate, 52.000 note from one otits customers on May 1, 2008. The entire balance is payable at the notes maturity. Prepare the May 31 adjusting journal entry related to this note. Do I debit cash and interest receivable; and ...

chinese
tian cai

chemistry
A jogger runs at an average speed of 5.9 mi/h. If she starts a run at 11:15 am, what time is it after she covers 4.75 x 104ft?

physics
shut up

environmental science for college

Aboringjob

MATH157
SUPPOSE YOU BUY 1 TICKET FOR \$1 OUT OF A LOTTERY OF 3000 TICKETS. IF THE PRIZE FOR THE ONE WINNING TICKET IS TO BE \$500, WHAT ARE YOUR EXPECTED WINNINGS?

Auditing
qtfq

apply the formula of (a-b)^2 i.e a^2-2ab+b^2. the required answer is 9x^2-24x+16.

Chemistry
why different detergents have different price?on what physical properties are their qualities based?

chemistry
A sample of silver chromate (Ag2CrO4) has a mass of 29.0 g. (a) How many Ag+ ions are present? (b)What is the mass in grams of one formula unit of silver chromate? (c) How many CrO42- ions are present?

chemistry
Determine the number of representative particles in each of the following and identify the representative particle. a. 13.0 mol Ag b. 23.7 mol H20 c. 0.178 mol NaCl

chemistry
how many grams of CaCl2 would be dissolved in 1.9 liters of a 0.2 molarity solution of CaCl2?

chemistry
Determine the number of moles of sulfate ions present in 1.20 mol iron(III) sulfate (Fe2(SO4)3).

social studies
what colonies French find as a result of the northwest passage way.

math
The sales representative informs you that there are two floor plans available, and that there are a total of 56 houses available. Use x to represent floor plan #1 and y to represent floor plan #2. Write an equation that illustrates the situation. The sales representative later...

spelling
well what is it? i don't get it :'(

social studies
Without our two great political parties cutting across economic and geographic interests, democracy as we know it could never have been made to function." The author of this statement probably meant to suggest that

physics
A 47.0 g golf ball is driven from the tee with an initial speed of 54.0 m/s and rises to a height of 23.2 m. (a) Neglect air resistance and determine the kinetic energy of the ball at its highest point. What is its speed when it is 9.0 m below its highest point

chemistry
Answer is 1480g Do the math. Someone already gave the formula. The cm cancels out after multiplying. Note: you have to cube the 5.5cm

ACCOUNTING
qwwq

life science
Explanation of why the process of mitosis and meiosis are both important to a living organism. When would an organism need to undergo the process of mitosis? When would an organism need to undergo the process of meiosis? What would happen if meiosis did not occur I will gladly...

algebra
i need help finding the base. this is the equation i got after work it out halfway. 42/h+h+sqroot(42/h)^2+h^2=20 ft how can i find B & H. How should i go about. Thanks. Isnt the sqrt of (42/h)^2 just 42/h ? Then, multipy both sides of the equation by h, that gives you a third ...

Life Science
How did Mendel’s approach to answering scientific questions differ from that of his contemporaries? Thank you for using the Jiskha Homework Help Forum. You might want to see the answer just posted for Diana.

help with solving
x^2+(x-2)^2 = (2x-6)^2 solve for x. thanks so much. Please keep in mind that tutors here won't simply do your work for you. I'm sure you'll get a better response if you show your work as far as you can get, so tutors will know where you get stuck. =) it was a word ...

algebra
solve for x (24+2x)(10+2x) - 240 = 152 First multiply. 24(10) = ___ 2x (2x) = ____ Now subtract 240. Can you finish the problem from here? dont i need to put this in equatic equation to solve for x. cause i need to find the width of a small rectangle inside a bigger triangle. ...

Life science
are humans subject to the same pressure of natural selction as other organism Humans show signs of natural selection occuring, according to these studies. http://www.news.cornell.edu/stories/Oct05/Bustamante.kr.html (Broken Link Removed)

Science
I need to know how to compare mouthwash and toothpaste...what to compare?.. compare bacteria samples in salaiva.