Questions Asked on
March 15, 2007

  1. physics.

    A 20.0 kg cannon ball is fired from a cannnon with muzzle speed of 1000 m/s at an angle of 37.0 with the horizontal. A second ball is fired at an angle of 90.0. Use the conservation of energy principle to find a] the maximum height reached by each ball and

    asked by Jean
  2. Physics

    Thanks for any help :) Four 20 ohm resistors are connected in parallel and the combination is connected to a 20V emf device. The current is: A) 0.25A B) 1.0 A C) 4.0 A D) 5.0 A E) 100 E Parallel circuits: I know that the voltage is 20V and the Resistance

    asked by susane
  3. Science/Chemistry

    Write a Balanced equation for the chemcial reaction Acetylene gas (C2H2) burns in a welding torch with oxygen to form carbon dioxide gas and water vapor. C2H2(g) + O2(g) ==> CO2(g) + H2O(g) It isn't balanced. I will leave that for you. How do i balance it?

    asked by Chris
  4. AP CHEM

    I would really appreciate some help on this problem. =) At 218 C, Kc = .00012 for the equilibrium NH4HS(s) NH3(g)+ H2S(g) Calculate the equilibrium concentrations of NH3 and H2S if a sample solid NH4HS is placed in a closed vessel and decomposes until

    asked by Jenn
  5. words

    what word means to cause a commotion that could ruin a starts like this rock_ _ _ _ _ _ _ ? Ms. Sue already answered this one. See below. To cause a commotiion that could ruin a plan: clue is rock

    asked by johns
  6. Enviormental Science ( Human Population)

    I need to find the missing word. An icrease in population could result from increased birth rate, increased __________, or immigration. Increased birthrates and immigration account for an increase in population. Decreased death rates also account for an

    asked by Mack
  7. physics

    When four people with a combined mass of 320 kg sit down in a car, they find that the car drops .80 cm lower on its springs. THen they get out of the car and bounce it up and down. What is the frequency of the car's vibration if its mass (empty) is 2.0 X

    asked by sam
  8. physics

    Four 20 ohm resistors are connected in series and the combination is connected to a 20V emf device. The potential difference across any one of the resistors is: A) 1 V B) 4 V C) 5 V D) 20V E) 80 V So there are four resistors that are 20 ohms. Their

    asked by susane (recheck thxs)
  9. words

    what is a huge limestone mass on Spain's southern coast? it starts with...rock _ _ _ _ _ _ _ _ _ _ _ help plz!!! Rock of Gibraltar.

    asked by Holly
  10. Physics

    A ceiling fan has two different angular speed settings: 1 = 475 rev/min and 2 = 170 rev/min. What is the ratio a1/a2 of the centripetal accelerations of a given point on a fan blade? Centripetal acceleration at a distance R and angular speed w is a = R

    asked by CJ
  11. Physical Science

    A donkey pulls a cart(c) with a mass of 240kg, attached to a log of wood(w), with a mass of 80kg on a horizontal road. W is tied to the back of c by means of non elastic rope. The donkey applies a foce of 170N on Cart c and the system accelerates at 0,3m

    asked by Taryn
  12. chemistry equation

    Write a net ionic equation for the reaction of iron(III)chloride and potassium thiocyanate. Fe+++ + CNS- ==> FeCNS++ This FeCNS++ complex ion is an intrnse red color.

    asked by Aubrey
  13. physics

    For any circuit the number of independent equations containing emfs, resistances, and currents equals the number of branches. why? The only type of circuit that branches is parallel. But there can be electric circuit with a combination of both parallel and

    asked by susane
  14. physics

    Given that x=Acos(wt) is a sinusoidal function of time, show that v(velocity) and a(acceleration) are also sinusoidal functions of time. (HINT: Use v=square root [(k/m)(A^2-x^2)] and a=(-k/m)X The hint tells you what to do: put Acoswt for X. A second way

    asked by steph
  15. Chemistry

    What other physical properties other than specific heat could be used to identify metals? spectroscopic lines and density to name two others. Melting point, boiling point, solubility in certain solvents are three others.

    asked by Jen
  16. Calculus

    Hello, I'm having trouble with this exercise. Can you help me? Integral of (x* (csc x)^2)dx I'm using the uv - integral v du formula. I tried with u= (csc x)^2 and used some trigonometric formulas, but the expression became too complicated, I couldn't

    asked by Maria
  17. chemistry

    Suppose a piece of lead with a mass of 14.9g at a temperature of 92.5c is dropped into an insulated container of water. The mass of water is 165g and its temperature before adding the lead is 20.0c. What is the final temperature of the system? The sum of

    asked by Jon
  18. Chemistry

    How do write a skeleton equation for this reaction? When heated, baking soda (sodium hydrogen carbonate) decomposes to form the products sodium carbonate, carbon dioxide, and water. Can someone please break it down so i can see how you got that ansewer?

    asked by Bryan
  19. chemistry

    How do these things shift the direction of a chemical reaction?: -adding/removing reactants -adding/removing products -adding/removing energy Thanks! It depends upon the equation and whether the reaction is exothermic or endothermic. Post the entire

    asked by Mira
  20. physics

    A small ball is set in horizontal motion by rolling it with a speed of 3.00 m/s across a room 12.0m long, between two walls. Assume that the collisions made with each wall are perfectly elastic and that the motion is perpendicular to the two walls. (a)Show

    asked by sam
  21. chemistry

    A solution of HCI has a density of 1.18 g/ml and is 36% (m/m). what is the molarity and molality of this solution? Assume 100g solution. Then the solute is 36 grams. Figure the moles for that. Then, you know density, so you can compute volume

    asked by nancy
  22. pre-algebra

    which measurement is the largest. 14mm or 1cm 1cm is 10 mm. It is time you learned this. how do you do this??? you know??

    asked by matt
  23. chemisrty

    hello how would i draw a monomer CH2-CHCH=CH2 I have to draw three monomer units can anyone help

    asked by bex
  24. Geography

    Each of these major rivers is associated with great population clusters having very high densities except one, which is it? a. Ganges b. Huang (Yellow) c. Indus d. Mississippi Look in the Atlas for those rivers and you can see which ones have the most

    asked by feroz
  25. Biology

    Write an equation to summarize the photo reaction of photosynthesis. Since this is not my area of expertise, I searched Google under the key words "photosynthesis equation" to get these possible sources: (Broken Link Removed)

    asked by Raj
  26. English

    what does this quote mean To write it, it took three months, to conceive it took three minutes; to collect the data in it- all my life.” I guess collecting data can be very time consuming. He is writing about his life experiences, and that would take an

    asked by Jay
  27. Chemistry

    If air has an average density of 1.29 g/l and Co is reported at 2.0 ppm, what volume of air will contain 1.00 mole of Co? There will have to be 1/(2*10^-6) = 500,000 times as much mass of air as CO. The mass of the CO is 28.0 g (1.00 mole), so that

    asked by nancy
  28. Environmental Science

    What steps do you think can be taken to reduce the harmful effects of human activities on biogeochemical cycles? Which businesses would these changes impact the most? Thank you for using the Jiskha Homework Help Forum. Here are some links on life and

    asked by Sheila
  29. Chemistry

    Could someone explain Le Chatelier's principle to me? Thanks Reactions tend to go to the direction that reduces stress: stress from pressure, temperature. If a reaction gives off heat (exothermic), it will go faster if temperature is reduced, ie, it is

    asked by Aubrey
  30. Social Studies

    need website that can help in social studies and has study materials THNX :) Here's one. If you'll be more specific about the topic and maybe the publisher, we can find more

    asked by Jaden
  31. pre-algebra

    how do i solve proportions??? please help!! And how do i kno what corrisponding sides are??? To solve a proportion, use cross products. For example, the proportion = can be solved as follows: = Write the original proportion. 50 n = 3 180 Find the cross

    asked by jaimmers
  32. social studies

    The fall of the Alamo occurred on March 6, 1836, where and when did the first battle leading to the Alamo occur??? Thanks! Thank you for using the Jiskha Homework Help forum. Here is the site giving the background of the battle:

    asked by Jules
  33. science

    As an environmental science teacher, how would you respond to someone who tells you (a) that he or she does not believe in biological evolution because it is "just a theory"? How would you respond if another student states, (b) we should not worry about

    asked by Trenet
  34. Biology

    How has the heart/lung machine changed health care, patients, and medical professionals? Since this is not my area of expertise, I'll give you information, so you can decide for yourself. I searched Google under the key words "heart lung machine" to get

    asked by Amanda
  35. pre algebra

    write an equation for the line through the given points or through the given point with the given slope (5,7),(6,8) (1,2),(3,8) (0,5),(-3,2) (8,11),(6,16) For each of them, use the standard formula (y- y1) = [(y2-y1)/x2-x1)]*(x-x1) In the first case, that

    asked by Anonymous
  36. Geography

    which of the following is an example of a physical feature on earths surface? a) Golden Gate Bridge b) Grand Canyon c) San Diego Zoo d) Sea World Physical features are not man-made. What do you think the answer is?

    asked by feroz
  37. g

    What modern city, once called Constantinople, lies partly in Europe and partly in Asia? a. Istanbul, Turkey b.Damascus,Syria c. Athens, Greece d. Skopje, Macedonia Read 1st paragraph

    asked by feroz
  38. human biology!!!

    hi i have a big problem got a practical, the effect of catalase on the rate of reaction on hydrogen peroxide. but i don't know the amount of hydrogen peroxide i should use or the source of enzyme? can anyone help? the source of enzyme cant be liver or

    asked by Sarah
  39. chemistryI

    If 2 protons and 2 neutrons are ejected from a radium nucleus with atomic number 88 and mass number 226 which element will be the result? Could someone please tell me how to work this out. Thanks. The atomic number is the count of if two are

    asked by laura
  40. words

    what word means to cause a commotion that could ruin a plan? clue:rock_ _ _ _ _ _ _ IT'S NOT ROCK THE BOAT!!!!!!!! rock the ship? Thank you for using the Jiskha Homework Help forum. Here are some things from the Online Thesaurus: Synonyms careen, lurch,

    asked by jay-jay : )
  41. Language Arts (Jaden) (Broken Link Removed) i need a wed site that has proper nouns and nouns i need a animal that lives in the water moves quickly away from

    asked by Ms. Sue
  42. Grammar

    IN the following sentence what words are the adverbs? "Up went the curtain and down went our spirits." I would choose Up and Down, only I thought they were prepositions? Now I am confused. thanks Pegg You chose correctly. In this case up and down are

    asked by Pegg
  43. rewrite the sentence in order

    friend two story on the lives in the corner house large My , . My friend lives in the large, two story house on the corner. My friend lives in the large, two story house on the corner. The two story house on the corner is the one my friend lives in. Try

    asked by jennifer
  44. Environmental Science

    A shortage of __________ can decrease the food supply available to a growing population. fertilizer? fuel? transportation? THere are many possible answers here.

    asked by Mack
  45. physical science

    force and motion Do you have a question? Not knowing what your specific question or your age is, I searched Google under the key words "force motion" to get these possible sources:

    asked by stephanie
  46. language arts

    need study sites for pronouns, propers nouns, adverbs, verbs, nouns. THNX :) Go into Word & Sentence Level for different specific grammar issues--most all of which have

    asked by vahnna
  47. reading

    what website is there that I can read the book: The Girls, by Amy Goldman Koss. I want to be able to read the entire book. The book is undoubtedly still under copyright, and because of this, you're very unlikely to find it online. Here is a collection of

    asked by chris
  48. science

    How do I use the fact that each element has a different set of energy levels to explain why the colour of the light emitted by an element in the gaseous state is characteristic of the element? Energy affects frequency and frequency determines wavelenght.

    asked by laura
  49. Economics

    If an economy is experiencing a recession will both aggregate demand and aggregate supply be affected? Yes. Think about how all important economic forces are changing/responding to recessionary conditions.

    asked by Sarah
  50. chemistry

    ho do you calculate final temperature? anyone please help thanks that's a little vague. Are you dealing with ideal gases? If so you would use the formula PV=nRT P = pressure V = volume of container n = moles (grams/molar mass) R = gas constant (0.0821) T =

    asked by shannon
  51. humanities

    i need a website where you can research your family tree THNX :) Thank you for using the Jiskha Homework Help Forum. If we knew the last name it is easier to find more information. Many geneology sites seem to charge to belong, but hopefully the following

    asked by vahnna
  52. pre-algebra

    it says use equivalent ratio's to solve the proportion!!! ok is there a different way to do them kind of proportions because i did it like that yesterday and my teacher said they were all wrong Give an example of what you did and how you came up with your

    asked by jaimmers
  53. Biology:respiration in plant

    How do i define the efficiency of respiration in words Since this is not my area of expertise, I searched Google under the key words "plant respiration" to get these possible sources:

    asked by bonita
  54. words

    what word means to shooot up suddenly............clue:_ _ _rock_ _ ___ rocket ?? isn't it skyrocket...johns and i have the same homework i think this is it to cause commotion that could ruin a plan isn't rock the boat i looked tup the u

    asked by johns
  55. chem

    In Fe(NO3)3, how many Fe atoms are there? One, three N, and 9 O. thank you

    asked by Lydia
  56. modern world

    Do yu think that the industrial movement's changes led or accounted for the socialist and fascist movements at all? Yes, industrialization had a lot to do with it. This online article supposrts that thesis:

    asked by cher
  57. Geography

    About a third of Canada's population lives in one province. Toronto, its largest city, and Ottawa, its capital, are located there. What is the province? a.Quebec b.British Columbia c. Indua d.Mississippi None of the above

    asked by feroz
  58. Math

    How would I would I solve this problem -25-75h=h+25 Add 25 to both sides. Subtract h from both sides. This should leave you with -76h = 50 Finally, divide both sides by -76

    asked by Dustin
  59. pre-algebra

    Rewrite the equation so the variable is alone. Solve to find the value of the variable. 42=-2h Divide both sides by 2. Then change the signs of both sides. That will provide the answer. Possibly in 1 step: Divide by -ve 2

    asked by Julia
  60. Biology

    What are the components of a photsynthetic unit, and what roles do they play? In which part of the chloroplast are photosynthetic units located?

    asked by Raj
  61. calculus

    i'm having trouble with a problem in my calc isn't really calculus yet since we're still in the review section but it goes somethign like this: ( don't have it in front of me) a rational function is defined by: R/(x-K) where R and K are

    asked by Rob
  62. words

    what word means to shoot up suddenly? i dunno Rocket

    asked by johns
  63. words

    what means to cause a commmotion that could ruin a plan? Diversion? johns and i have the same homework and it also starts with rock_ _ _ _ _ _ _ Rock the boat?

    asked by johns
  64. human biology

    does DNA serve as a template for just DNA or mRNA as well? Go here: and scroll down to: How can RNAi be used to treat HD?

    asked by sophia
  65. Math

    Which of these numbers is greater than 6 but less than 7? Let me try to figure it out and I'll post my anwser.= ) oops didn't put the options in... the square root of each of these numbers a. 6.5 b. 67 c. 45 d.76 Would it be easier to find the number which

    asked by Holly = )
  66. chemisrty

    how would i draw a structual formula of the products of the complete hyrolosis of tocainide O CH3-N-C-CH-NH2 CH3 H CH IM told this is tocainide please can anybody help a distressed student the O should be over the C atom

    asked by bex
  67. English Lit

    Where could I find suitable literary criticism on Tennessee William's 'Cat On A Hot Tin Roof' regarding disability and disadvantage? is this a significant enough theme for there to be any useful resources on the internet? Depends. William's Cat On a Hot

    asked by Sam
  68. chemisrty

    Is this the stuctual formula for hydolosis of tocainide CH3 NHCOCH^2N(C^2H^3)^2 CH3 WITH THE HEXAGON LINKING THE 2 X CH3

    asked by bex
  69. english

    In the sentence...We are moving to Belgium, a European country. Is Belgium a noun or adjective? Belgium is a noun. ty Ms.Sue

    asked by Holly
  70. conditioning

    is obesity an inherited gene No. The tendency of Americans to become obese, and even morbidly obese, has shown up markedly in the last two generations. If it were inherited, it could be to an evolutioary case of "survival of the fittest", which obviously

    asked by jamie
  71. algebra

    Can someone please help me with this problem? 4x-1 ---- 2x^2+3 Can you simplify this any further? no, its done thanks

    asked by Lydia
  72. drivers ed...again

    on a divided highway, all vehicles must stop for a loading school bus?? true or false??? True That depends upon your state. Most states do not require traffic on the other side of a divided highway to stop. Please check out these sites to see which law

    asked by [.andrea.]
  73. College math

    -3-4(t-5)=-2(t+3)+11 Multipy out the terms in parentheses and then combine the constants. Adding "2t" to both sides will leAave you with -2t on the lest side. Then solve for t

    asked by Alecia
  74. hi johns

    j.j. is someone home HollY lol

    asked by Anonymous