# Posts by jana

Total # Posts: 129

**Chemistry**

I figured it out. :) Wolframalpha Failed to understand what i meant and have me the wrong answer even though I did everything correctly.

**Chemistry **

Can someone clarify where I'm going wrong with this? Kw for pure water is 1.2 x 10-15 at 5°C. The pH of pure water at 5°C? I thought Kw=[H3O][OH]... I've tried a few different things, but none seem to work. Thanks!

**math**

I am a two digit number my ones digit is the double of my tens digit two of my divisor are 8and 12

**Chemistry**

It's the reactions: 6H++ BrO3-+ 5Br- --> 3H2O+ 3Br2 2 Cu2+ 4I--> 2CuI + I2 2H++OCl- +Cl- --> Cl2+H2O

**Chemistry**

describe the preparation of 12 mL of a 0.050 M solution of each of the halogens, using the reactions in the preceding question. Available to you are solid Ca(OCl)2; 0.20 M solutions of NaCl, NaBr, NaBrO3, and CuSO4; a 0.40 M solution of NaI; a 0.50 M solution of H2SO4; ...

**Physics**

nm. I figured it out :)

**Physics**

Circular motion: Not sure if I did this right. I need to find the speed that a spaceship needs to rotate to create an artificial gravity of 9.8m/s^2 (at feet) r=10m a=V^2/r 9.8=v^2/r root of(9.8*10)=v v=9.9m/s is this close?

**Science**

How do humans grow crops on land that would naturally be either too dry or too wet ? Explain

**Physics**

I don't need somone to fully answer this questions, but I need help as to where to get started. Occasionally a severe leg break requires traction to help the bones heal properly. While in traction, the leg is held stationary in the air and is under tension by a series of ...

**chemistry**

Paper pulp is sold on the basis that it contains 12% moisture; if the moisture exceeds this value, the purchaser can deduct any charges for the excess moisture and also deduct for the freight costs of the excess moisture. A shipment of pulp became wet and was received with a ...

**Math (pre-celc 12)**

Given (f+g)(x)=10-3x and (f-g)(x)=5x-14) find f(x) and g(x). So I was told to do: (f+g)(f-g)=2f 2f=(10-3x)+(5x-14)=2x-4 f(x)=x-2 For g(x) I tried: -2g=(10-3x)+(5x-14)=2x-4 g(x)=-x+2 is that correct?

**Math (pre-celc 12)**

So, g-g=0 wouldn't that get me g(x)=0?

**Math (pre-celc 12)**

Given (f+g)(x)=10-3x and (f-g)(x)=5x-14, find f(x) and g(x). I'm not sure how to go about this.

**English Check answers**

I think you're right for all.

**math**

Not a question.

**Math (pre-celc 12)**

Thanks for typing that all out! It really helped.

**Math (pre-celc 12)**

A true false test has 15 questions. How many answer keys are possible of the answer to 6 of the questions is false and 9 are true? I think this is a permutation and not a combination because each answer key would be different depending on the order of which are true or false. ...

**Math (pre-celc 12)**

In how many ways can a school president, a vice-president, and secretary be chosen from 21 students? I'm not sure to find this answer since there is no order in which they are chosen.

**Math (pre-celc 12)**

BC Place has 16 gates. In how many ways can you enter and leave the stadium by any gate? I'm not sure if this this is a combination or a permutation. I think it's a permutation and my answer is 256 ways. Thanks for the help.

**Physics (Normal force and static coefficient)**

Oops, the units for gravity are incorrect, it should me m/s^2.

**Physics (Normal force and static coefficient)**

Calculate the normal force for a 2 kg object at rest on an inclined surface, α=42 degrees How much is the static coefficient of friction between the surface and the block ---- My work: N = mg*cos(θ) N = (2kg)(9.8n/m^2)cos(42) = 14.57 N F = µsN µs = F/N &...

**Math (pre-celc 12)**

I need to prove this identity: cot(x)+tan(x)=csc(x)sec(x) I get as adding them together, but then I get stuck.

**Math (pre-celc 12)**

Never mind I figured it out!

**Math (pre-celc 12)**

I'm not sure how to get the final answer for this question I get stuck halfway thru. Simplify using sum and difference identities: cos((3pi/2)-x) I think the answer is supposed to be -sin(x) Thanks!

**math**

Neither: 7+4+3=14 7+3=10 10/14 (or 5/7) marbles are not red so you have about a 71% chance of not getting a red marble

**Math (pre-celc 12)**

thanks!

**Math (pre-celc 12)**

I'm not sure how to solve this equation algebraically: 38=20sin((2pi(t))/36)+22 I know the answer should be about 5.3 since I graphed it. I can get as far as removing 22 from the right and then removing 20 from the right by dividing by 20. To get 0.8=sin((2pi(t))/36)

**Math (pre-celc 12)**

Thanks! Great explanation.

**Math (pre-celc 12)**

Write an expression for the x-values where the the maximum in the expression occurs: y=6cos((2pi/14)x)-2 I know that the maximum occurs every 14 units if you start at 0,0. I'm stuck after that.

**Math (pre-celc 12)**

thanks Bob :)

**Math (pre-celc 12)**

Write the expression as a single logarithm: 3log(a)-log(b)-(1/2)log(c) I want to check my answer. I got log(a^3/bc^(1/2))

**Math (pre-celc 12)**

Thanks. That really helped!

**Math (pre-celc 12)**

Find x: 2(5)^x=3^(x+1) I'm not sure what to do with the 2. I think I need to write the equation as log5^2x=log3^(x+1), but I don't know. Thanks

**ALGEBRA**

so (x+4)^2 is the same as (x+4)(x+4) Find the roots: x+4=0 x=-4

**Math (pre-celc 12)**

Thanks!

**Math (pre-celc 12)**

Factor 2x^4-62x^2+60x I get: 2x(x^3-31x+30) 2x(x-30)(x^2-1) 2x(x-30)(x-1)(x+1) But that's wrong. It should be (I think): 2x(x-1)(x-5)(x+6) Please show me where I went wrong.

**English**

I'd say "he is a unique and blessed person" unless you're writing as a character who would say it like that. It sounds more clear to me.

**Math**

area=Length x width so, what are the factors of 42?

**Math (pre-celc 12)**

Solve this algebraically for the exact values (Meaning find the x-intercepts): (1/x)=x/(3x+18) I'm not sure what to write as the common denominator. I thought it was: 4x+18 because (3x+x+18)=(4x+18), but I'm not sure what to do from there. Thanks!

**Chemistry**

1. Before the Industrial Revolution, the concentration of CO2 in Earth’s atmosphere was about 275 ppm. Considering the effect of CO2 only, calculate the effect that the increase in CO2 has had on the pH of precipitation

**Trigonometry**

If the terminal side of angle theta passes through point (-3, -4), what is the valuse of sec theta? 1) 5/3 2) -5/3 3)5/4 4)-5/4

**math**

I noticed that Ms. Sue. I must be getting tired, so I'm going to stop before I do something like that again.

**math**

IGNORE MY FIRST ANSWER 3/4 = 75%

**math**

3/4 = 25% = 0.25 25% of 160 = 160 x 0.25 Try it and see what you get.

**math**

remember, one is removed from the original total.

**math**

Hint: How many red socks are left after she removes one? How many socks are there in total?

**algebra**

Don't worry. Just remember you need to find x. You can't do that with x on both sides, right? It's in 5x and 4x. Get x to one side. Remove 5x from the right. Whatever you do to one side you do to the other. 4x-5x=-1x (do not remove x as it can be any number and is ...

**algebra**

PS: You don't need to start with the -9. You can start from either side. For example: you could have subtracted 2 from both sides to get -11. 5x-11=4x Then keep going

**algebra**

Step by step: You want the variable "x" on one side. first: Remove -9 from the right y adding 9 to each side to get: 5x + 11 = 4x Get the other term with "x" in it by subtracting 5. From both sides. Remember that 5x and 4 x are the same term because the ...

**Math**

you want H (aka height) Volume = length x width x height Volume/(Length x width) = height

**Math**

No, it's C D gives you the number for length and width multiplied together. Sorry Luis

**Physics**

Is there a question in there?

**Science**

Yes sir! Nice work.

**Science**

You asked this twice ;) Not even going to guess? Let me give you some hints: What variables are the same for each? B) does not address the variable They know what condensation is.

**Science**

Not even going to guess? Let me give you some hints: What variables are the same for each? B) does not address the variable They know what condensation is.

**Science**

Not even going to guess? Let me give you some hints: What variables are the same for each? B) does not address the variable They know what condensation is.

**Math**

Pi never ends and it never repeats a sequence.

**Math**

Zero. Pie is a food. Pi on the other hand has an infinite number of digets.

**Biology**

Wow, look how smart I am! I didn't even ask the question. We are learning about proteins and their structure, but one thing is confusing me. At what structural point is something considered a protein? Is a protein formed after two amino acids synthesis, or is a protein the...

**Biology**

I'm going as this question again as it seems to far down the list to be answered now. Sorry if this is considered spam.

**science help**

The second answer is correct. That is part of the reason it is so bad to kill coral reefs. No reef = no oxegen

**Biology**

Thanks! Great answer. :)

**Biology**

We are learning about proteins and their structure, but one thing is confusing me. At what structural point is something considered a protein? Is a protein formed after two amino acids synthesis, or is a protein the whole structure (all four levels) put together? I would think...

**english**

I'd say A too.

**math**

the normal line to the curve y=f(x)=2x^2 at a point in the first quadrant passes through the point (0,3/4). find an equation of this normal line

**Calculus**

Which of the following integrals cannot be evaluated using a simple substitution? the integral of the square root of the quantity x minus 1, dx the integral of the quotient of 1 and the square root of the quantity 1 minus x squared, dx the integral of the quotient of 1 and the...

**math**

R,O,C,A are the midpoints of the sides of the rhombus DJSB. if DJ= 16 sq rt of 2 cm and d=120 degrees, what is the perimeter of ROCA?

**English**

what is a minor transtion of a text?

**Language Arts**

Booo is litt

**English 9**

I thought it was A but wasn't sure thoughts?

**English 9**

. Read the following line from Romeo’s monologue in Act II, Scene 2 of Romeo and Juliet, where Shakespeare employs personification: Arise, fair sun, and kill the envious moon, Who is already sick and pale with grief, That thou her maid art far more fair than she: Be not ...

**Creative Title Help**

What would be a creative title for an essay paper over the causes of wildfires?

**DENTAL ASSISTANT HELP PLEASE!!!!!!**

As the administrative assistant, the clinical assistants have asked you to clarify this assignment. What should the administrative assistant and the dentist do to rectify this situation ?

**Science 207**

the hotter the more evaporation will happen but the colder the less evaporation will happen. Molecules move faster when the temperature is increased Molecules move slower when the temperature is decreased

**Science help!!!!**

cool thx got XD :D x/

**English**

For vocabulary workshop, Unit 11 # 19. Her ability to _______ the words and gestures of prominent Americans makes her an excellent comic impressionist. Is the answer: parody ???

**Accounting**

1. On July 1, 2010, Harris Co. issued 6,000 bonds at $1,000 each. The bonds paid interest semiannually at 5%. The bonds had a term of 20 years. At the time of issuance, the market rate of interest was 7%. Harris uses the effective interest rate method to amortize bond premium ...

**math**

The ratio of apples to oranges at a fruit stand is 4 to 5. There are 60 oranges at the stand. How many apples are at the fruit stand?

**Statistics**

In a survey of 1233 people, 917 people said they voted in a recent presidential election. Voting records showed that 72% of eligible voters actually did vote. Given that 72% of eligible voters actually did vote, find the probability that among 1233 randomly selected voters, at...

**Statistics**

An engineer is going to redesign an ejection seat for an airplane. The seat was designed for pilots weighing between 140 lb and 181 lb. The new population of pilots has normally distributed weights with a mean of 146 lb and a standard deviation of 28.9 lb. A) If a pilot is ...

**Statistics**

In a genetics experiment on peas, one sample of offspring contained 421 green peas and 166 yellow peas. Based on these results, estimate the probability of getting an offspring pea that is green. Is the result reasonably close to the value of 3/4 that was expected ?

**Statistics**

The probability of a randomly selected car crashing during a year in a certain country is .0479. If a family has three cars, find the probability that at least one of them has a car crash during a year.

**statistics**

Sorry, forgot the last line - Find the probability that not enough seats will be available.

**statistics**

An airline has a policy of booking as many as 17 persons on an airplane that can seat only 16. (Past studies have shown that only 89% of the booked passengers actually arrive for a flight.) Find the probability that if an airline books 17 persons, not enough seats will be ...

**Statistics**

How do I figure out the answer to this ? It's been a while since I came across one like it; On a test, 6.25% of the questions are answered incorrectly. If 5 questions are answered incorrectly, how many questions are on the test ?

**math**

third one is 0.55

**math 5th**

a rectangle playground has an area of 3,450 square meters. if the width of the rectangle is 35meters.find the length?

**AP Chemistry**

0.015 moles of a compound are dissolved in 18 fl. oz. of water. At what temperature will the solution begin to freeze? The density of water is 1.00g/mL

**chemistry**

CaCO3(s)+2HCl(aq)-->CaCl2(aq)+H2O(l)+CO2 (g) How many grams of calcium chloride will be produced when 31g of calcium carbonate are combined with 11 g of HCl? I have 0.3097 moles of CaCO3 and 0.30169 moles of HCl...I get stuck at that point

**Chemistry**

calculate the wavelength in nm of the spectral line produced when an electron in an hydrogen atom undergoes the transition from n=3 to n=2. I get 6.56x10^-7 meters and 6,561.68 nm but that is not the right answer...help please!

**Physical Science Need Help Please!**

A light beam has a frequency of 5 x 1015 Hz. What is its wavelength?

**english**

life is full of choices, so i must learn to make good ones.life is a noun choices which other one

**College**

Another term that means the same thing as "insurance company" is:

**Calculus**

y=3+2ln|x|

**Calculus**

y=14x+3

**science**

What is the amount of water needed to obtain a saturated solution using 27g of barium nitrate? What mass of water is present

**Math**

A picture frame measure 5 inches wide and 7 inches long . What is the perimeter of the frame ? (16-3)

**Mathematics**

How can the number 39 be divided into two parts in order that the sum of 2/3 of one part and 3/4 of the other part is 28? Explain your workings

**chemistry**

calories given off when 89g of water cools from 44degrees C to 29 degrees C

**8th grade science**

No, loudness has no direction