Posts by nathalie

Total # Posts: 44

Thermodynamics
400 g of water are emptied at 20 ° C in a vessel. The container is placed at Fire of a flame that gives it a certain amount of thermal energy of So that it takes 5 minutes for the water to reach a temperature of 90 ° C. If the vessel does not absorb thermal energy, a) ...

Math word problem
so 1.50(x)/4 + 4.00(y)/4 = 712/4 0.375(x) + (y) = 178 (x) + (y) = 258 --------------------------------- -0.625(x) + 0(y) = -80 x= -80/-0.625 x= 128 x + y = 258 128 + y = 258 y = 258 - 128 y = 130 x = 128 (number of children tickets) y = 130 (number of adults tickets) And it ...

Math word problem
The admission fee at an amusement park is $1.50 for children and$ 4.00 for adults. On a certain day, 258 people entered the park, and the admission fees collected totaled \$712 . How many children and how many adults were admitted? I tried doing it this way; x = amount of ...

thank you so much steve i get it. a|b, b=ae a|b+1, b+1=af substituting, ae+1=af 1=a(e-f), we conclude that a|b+1-b therefore a|1, a = ±1

True or False: If a|b and a|(b + 1), then a = ±1. [NOTE: Use this Theorem 3: If a|b and a|c, then a|(bx+cy) for any integers x and y. PROOF: Since a|b, there is an integer u such that b = au. Since a|c, there is an integer v such that c = av. Substituting, bx + cy = aux...

Math
Gene ad jay has collection of marbles. If jay give gene 2 of his marbles they would have an equal number. But if gene give jay 2 marbles, jay have 2 times as many as gene. How many marblea does jay have?

math
So 1/6

Math
jon drove 843 miles and rick drove four times as many miles how many miles did rick driv

science
What is the percent by mass solution made by dissolving 163g of table sugar cm 755g of water

math
A concert promoter wants to give away 240 tickets to 3 radio stations. Which basic math fact can he use to find 240 image 3 using mental math?

Mathematics
I need help on this following question there are 45 choirs members going to the recital.Each van can carry 8 people.How many vans are needed?

geometry
tan (?) = 3.5

math
4/5

chemistry
calculate the pH of the solution when 25.0ml of 0.0920M HCL is titrated with 0.15ml, 23.0ml, 30.0ml of 0.10M NaOH

algebra 2
find all the zeroes of: x^5-3x^4-24x^3-72x^2-25x+75=0 5x^5-20x^4-40x^3-16x^2-45x+180=0 -3x^5+3x^4+9x^3-7x^2+12x=12 x^3-x^2-13x-13=0 x^3+x^2=15x-15 Thank you for any help...I'm desperate please help :(

Organic Chemistry
Thin Layer chromatography TLC experiment What does it mean when it says with to much sample the spots will tail

Math
5.625

849 750

statistics
suppose 25% of the urban population is 18 years old or younger. five residents of that city are selected at random find the probability that at least two of the selected five persons are 18 years old or younger. please help me with this question !!!

historty
who was lowell mill strikers

geometry
what kind of geometric figure is an angle bisector

public health
What are the purposes of public health surveillance? How are they implemented and utilized by communities, governmental agencies, and health care organizations or providers?

healthcare
ok thanks that is like the sanitation stage of 1800,s how they practiced using different techniques to help clear diseases.

A concert promoter wants to give away 240 tickets to 3 radio stations. Which basic math fact can he use to find 240 image 3 using mental math?

Chem
Aviation fuel is significantly more expensive per gallon than diesel fuel. Why then is aviation fuel still used in Planes?

fau
The mass of an electron is 9.11\times 10^{-31}~\rm kg. If the de Broglie wavelength for an electron in a hydrogen atom is 3.31\times 10^{-10}~\rm m, how fast is the electron moving relative to the speed of light? The speed of light is 3.00\times10^8 ~\rm m/s.

PHYSICS- Laws of Motion
When the cathode is heated from the 6.3 V AC supply, electrons are emitted from its surface. These electrons fall on the grid (which is positive) and a current flows in the cathode/grid circuit. As electrons stream from the cathode toward the grid, they bombard atoms of the ...

natural science
What are the structural zones within the Earth? How are they detected scientifically?

French
I hope this question isn't too broad but.. When do you not pronounce the final letter of a word when the next word begins with a vowel? I hope that makes sense. I know that you are never supposed to say the "T" in "et" when it comes before a vowel but ...

Debate
Can someone give me some tips on how to do well in a debate and possibly win? I have an opening and closing statement, arguments for my topic, and arguments against the other topics. We are talking about the best alternative to using petroleum. My choice was public ...

French
What is the best way to say this? When one has a flat tire, it is necessary to put air in it. I have to translate this, and my best guess is Quand on a pneu à plat , il faut mettre de l'air dans ça That doesn't really look right me at the end. Could ...

History
Oops, I guess coying and pasting doesn't work here. Here are the rest: 5. Henry II 6. Richard the lionheart 7. John 8. Henry III 9. Edward I Longshanks 10. Edward II 11. Edward III 12. Henry VII 13. Henry VIII 14. Edward VI 15. Mary I 16. Elizabeth I 17. James I 18. ...

History
I asked a question about the monarchs of England earlier, and I did my timeline. Except there are supposed to be 23, and I only have 22. I am not supposed to add the monarchs of the Hundred years War or the Wars of the Roses. Can someone please check to see if I am missing one...

History
Who were the English Monarchs during the War of the Roses? And the Hundred Years War? During the wars of the roses, was it just Edward IV, Edward V, and Richard III? My teacher said there were four or five of them. And for the hundred years war was it just Richard III, Henry ...

French
I have to write a paragraph about driving and my car with a story about a driving experience. Unfortunately I forgot my book and I'm trying to come up with something on my own. My French isn't that good either. Could someone please help me with the words I don't ...

Math... Sort of
How much would 10 cents be worth in 1906? (Like relative to how much it would be worth now)

Chemistry
Ok thanks so much.

Chemistry
So.. my work wasn't right. Above your message?

Chemistry
Would you take the percentage of aluminum in the ore: 53.96/101.96 = 52.92 then take that much out of 2.0 metric tons or 2000 kg? So would it be 1058.40 kilograms?

Chemistry
How many kilograms of aluminum can be extracted from 2.0 metric tons of the ore 'alumina' (Al2O3)?

Chemistry
Could someone please check my Chemistry homework? The molecular formula for cisplatin, a chemotherapy agent, is PtCl2(NH3)2 (The numbers are all supposed to be subscripts) 1. What is the molar mass of cisplatin? Ans: 300.06 g/mol 2. How many moles of hydrogen atoms are in one ...

psychology
i think the answer of the question is B

living environment help!
what are 3 services which the fruit provides for the plant? Since this is not my area of expertise, I searched Google under the key words "fruit plant function" to get these possible sources: http://en.wikipedia.org/wiki/Flowering_plant#Fruit_and_seed http://www....

galnds and their functions
Why are aspirin and ibuprofen effective in treating headaches? Thank you for using the Jiskha Homework Help Forum. Aspirin and the NSAIDs inhibit cyclooxygenase, leading to a decrease in prostaglandin production; this reduces pain and also inflammation (in contrast to ...

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