1. physics

Please see if I am doing this problem right. A mixture of gasoline vapor and air is placed in an engine cylinder. The piston has an area of 7.4 X 10^-3 m^2 and is displaced inward by 7.2 X 10^-2 M. If 9.5 X 10^5 Pa of pressure is placed on the piston, how

a. Two sticks are rubbed together to start a fire. b. A firecracker explodes. c. A red-hot iron bar is set aside to cool. In which of the situations listed above is energy being transferred as heat to the system in order for the system to do work? I would

3. Economics

Why do people routinely stuff themselves at all-you-can-eat buffets? Explain in terms of both utility and demand theories. At any level, the marginal cost of take another bite at an all-you-can-eat place is zero. In terms of utility, a person should

4. physics- isothermal, isovolumetric, or adiabatic

Please check my answers. Identify the following processes as isothermal, isovolumetric, or adiabatic: a. a tire being rapidly inflated- adiabatic b. a tire expanding gradually while heating- isothermal c. a tire being heated while in a rigid metal

5. Elements

Which elements result if two protons and two neutrons are ejected from a radium nucleus with atomic number 88 and mass number 226? What element is atomic number 86 and mass 222? Sorry, should be atomic number 88. Huh? It ejected two protons, changing the

6. Science/Chem

How many representative particles are in 2.5 mol H2O2? each mole consists of 6.02*10^23 things. Memorize that.

7. physics

Two charges are fixed in place with a separation d. One charge is positive and has nine times (n = 9) the magnitude of the other charge, which is negative. The positive charge lies to the left of the negative charge. Relative to the negative charge, locate

8. Chemistry

If you divide the molar mass of a compound by the empirical formula mass, what is the result? That division should be VERY close to a whole number. Usually, 0.9 to 1.1 or 1.9 to 2.1 (all depending upon the accuracy and precision of experimental data). That

A sinusoidal wave travels along a string. The time for a particle to move from maximum displacement to zero is 0.170s. What are the a)period b)frequency c) the wavelength is 1.40m what is the wave speed? ok I know i need the equation T=1/f and the wave

10. English, Hamlet

Statement one: "The woman in the play are wimps completely dominated by te men in theirs." Question one: Discuss this statement critically and show how this adds to the tragic effect of the play. Statement two: "Different conflict situations throughout the

11. Ap Chemistry

A 3.0 molal solution of naphthalene in cyclohexane boils at 89.4 C. What is the boiling point of pure cyclohexane? Although solid naphthalene is slightly volatire, assume its volatility is zero in this calculation. The constant kb for cyclohexane is +2.80

12. chem

C2H4Br2 + 3 I- -> C2H4 + 2Br- + I3- [C2H4Br2]M [I1]M Initial Rate (M/s) 1 0.127 0.102 6.45 x 10-5 2 0.343 0.102 1.74 x 10-4 3 0.203 0.125 1.26 x 10-4 Determine the order of the reaction in C2H4Br2:

13. chemistry

Hi you guys please help me with my chemistry homework, i need to find all these items and take them to my class in a ziploc bag *a hydrocarbon with a molecular mass greater than 100g/mol *2 porpanol *an aromatic compound(not the common usage of "aromatic"

14. Mechanics

A force of 25N causes an acceleration of 2m/s^2 when acting on a 7kg mass. What is the frictional force also acting? If body is moving then frictional force is at its maximum. acceleration in direction of friction is -2 M=7. a=-2 F= frictional force

15. math

Will someone please show me how to do this problem. I have to write this ratios in simplest form. The ratio of 5 3/5 to 2 1/10. Change each of your mixed fractions to an improper fraction, then divide the first by the second. Remember to divide fraction #1

16. mass/density

If 1 cc of a substance has a mass of 1.5 g, the density is what? I think it is 1.5 but not sure. density = mass/volume d = 1.5 g/1 cc = 1.5 g/cc.

17. chemistry

thanks for helping me with the list. By checking the product's labels I'm finding many of the substances the problem now is that i found a product with hydrocarbon in it but I do not know how to figure out if its molecular mass is greater than 100g/mol

18. physics

The electronic flash attachment for a camera contains a capacitor for storing the energy used to produce the flash. In one such unit, the potential difference between the plates of a 760 µF capacitor is 315 V. (a) Determine the energy that is used to

19. Hydrogen

Why does a hydrogen atom, which has only one electron, have so many spectral lines? Any help gratefully received. There are many energy levels the one electron can transition from/to.

20. Chem

A vessel of 6.84 L in volume contains 3.61 L of pure water at 25°C. A partial pressure of 3.67 atm of CO2 is quickly injected into the space above the water. Calculate the partial pressure of carbon dioxide remaining once the solution has become saturated

21. Communication

how technology is used to enhance visual communication These sites have some interesting information. http://www.ncrel.org/sdrs/areas/issues/content/cntareas/reading/li300.htm http://linkinghub.elsevier.com/retrieve/pii/S088539240100402X

22. Science

Which parts of the frog's nervous system can be observed in its abdominal cavity and hind leg? spinal nerves

23. chemistry

I have a problem that I need help with. The diameter of the oil molecule has to be calculated and presented in scientific notation. The data in the questions tells me that drop of oil(volume 0.05cm ^3) is released from a dropper onto the surface of the

24. graph from asymptotes

Is it possible to roughly sketch a graph(without plotting the points) from the asymptotes of a rational function? Is yes, what are the rules? For example, if I have to sketch a graph of y = (2x^2+10x-12)/x^2+x-6), how do I do it? I got the vertical

25. Chemistry (Check)

True or False The empirical formula of a compound is always the same as the molecular compound. My Answear: True The empirical formula for acetylene is CH. The molecular formula is C2H2. Another example: The empirical formula for glucose is CH2O. The

26. Writing

What factors might influence your decision to use a memorandum format rather than a manuscript format for a short report? If your main purpose is to convey information as briefly, quickly, and consisely as possible, the memorandum format best fits your

27. chem

The (aq) solution with the lowest freezing temperature would be which of the following: 0.010M NaCl 0.020M NaCl 0.030M C6H1206 0.030M NaNO3 0.030M HC2H3O2 The NaCl and the NaNO3 break up into two particles each. The sugar does not, and the acetic acid

28. Literature Question

I have this question on a homework assignment and I am confused! It is not wise to rely on the__________ to determine whether a stereotype exsists in a book. (Here are the choices the assignment gives me to complete the sentence) A. title B. illustrations

29. Chemistry (Help)

Completion (Help) To find the mass of a mole of a compound, scientists add together the __1____ of the atoms making up the compound. When you substitute the unit grams for amu, you obtain the ____2____ of the compound. There are __3____ representative

30. Writing

Josie wrote a newspaper advertisement about the school cafeteria's meatloaf. She wanted everyone to try it, so she explained how delicious it was and why they should eat it.Was her advertisement an example of descriptive,persuasive, narrative, or

31. Chemistry

Im fed up with this assignment please help The oxide formed when selenium burns in air dissolves in water to give a solution of selenious acid, H2SeO3. The solution conducts electricity, and turns blue litmus paper red. State the evidence that supports

32. history

whta were the three most populous states in 1860? were they northern or southern states? http://www.civilwarhome.com/population1860.htm =)

33. Chemistry

Is this equation balanced? 2HCl(aq) + Ca(OH)2(aq) -------> 2H2O + CaCl2 yes. It helps in these to write water as HOH, in this you would have had 2 HOH

34. Debate

Hello, I have to create a debate for my English class. I am debating a difficult topic, and I was hoping I could get some good ideas on where to start. My topic is that I have to prove that love is not nessicary for survival. Does anyone have any good

35. Chemistry

Completion To calculate the percent composition of a known compound, start with chemical formula of the compound and calculate the ________ which gives the mass of one mole of the compound. formula mass. molecular mass.

36. Chemistry

Hi you guys please help me with my chemistry homework, i need to find all these items and take them to my class in a ziploc bag *a hydrocarbon with a molecular mass greater than 100g/mol *2 porpanol *an aromatic compound(not the common usage of "aromatic"

37. to KEEGAN

Please use "Post a New Question" and then be sure to ask a question! Please note that we don't do students' homework for them. Our tutors try to give you the information to help you complete your assignment on your own. Then once YOU have come up with a

I started having trouble on part (c), and I need to know this before I can go onto the other problems. Plz help! The parabola shown at the right (no picture, sorry) is of the form y=x^2+bx+c. The graph's y-intercept is (0,2), the axis of symmetry is -2.5

39. Math

A golfer hits a ball off the ground with an initial velocity of 200 ft/s at an angle of 23 degrees. The green is 750 feet away. Will the shot make it to the green? State by how much it makes or misses the green. What is the vertical velocity? 200*sin23.

40. chemisrty

can anybody give me the density of arsenic oxide at STP is this the correct formula volume = mass/ density thanks Yes, but if you want the density, it is density = mass/volume. The number I have seen floating around on this board is 17.8 g/L but the

41. chemistry

I can't find a substance apart of water with a pH of 7,so i have a question, i don't know if water is the only neutral substance or if there are more which one's are those? Any salt solution that doesn't hydrolyze in water will be neutral. Any liquid

42. Chemistry (Check)

Completion 1) 2)6.02 X 1023 Chemists relate units of counting, of mass, and of volume to a single quanity called the _______. The number of representative particles in a mole of a substance is _______. mole. 6.02*10^23 to find the mass of a mole of a

43. Plz Help Physics

We know that the negative charge on the electron and the positive charge on the proton are equal. Suppose, however, that these magnitudes differ from each other by 0.00011%. With what force would two copper pennies, placed 1.4 m apart, repel each other?

44. Physics

Help me out! Thanks! You guys have really helped me before. Question 1 What does the law of inertia say about the velocity and acceleration of a body that is subject to no external influences? a) The velocity slows to zero as the object decelerates. b) The

45. AP Chemistry

1. The heat of solution of salta may either be endothermic or exothermic. What factors determine this? 2. As a solution freezes, why does the freezing temperature continue to decrease? 3. When the concentration of very dilute aqueous solutions are

46. Mechanics

What is the decrease in elevation of a 4-kg body whose kinetic energy increases from 20 J to 100 J as a result of moving downward along an inclined plane? set Potential energy change equal to KE change mgh= change in KE thanks a lot!

47. Math

1.3x^2+17x+10 2.5y^8-125 3.a^2-2ab-15b^2 *Please help me.You have to factor by completing. Let's look at #1: 3x^2 + 17x + 10 We have 2 and 5 as factors of the last term. What combinations can we do to arrive at the middle term? (3x + ?)(x + ?) Let's try

48. chemistry

how do I get the percent deviation of a value? I got he answer already thanks any way:) What is the highest fluride of Uuh? answered above.

49. math2(count iblis)

-y^3(2x^2y-4xy^2)=-2x^2y^4+4xy^6 *is this correct.? No, in the last term, the y should be to the fifth power (3+2)

50. Maths

Given that arg((z-1)/(z-2i)) = pi/4 describe the locus of P and sketch this on an argand diagram. Show that the point (1,3) lies on this locus. I know it is an arc subtended from the points (0,2) and (1,0) but I do not know how to find the centre of the

51. the same different question

B) r h o e e y e y m s r u w_a_ m_ _ea_t _l__ve hint ...or my lungs open my collar http://www.ojohaven.com/fun/crossword.html Maybe this will help you very neat site. Here is another dictionary site: Put * in for the missing letters.

52. urgent

hey you guys I post a question like five hours ago and I would like to know if there is at least a website in were I could get help or something Post your question again. That way it'll get to the top of the list. That's what I always do. Your original

A company is considering a \$250 million investment in land that it will hold for 25 years. The pretax net cash flows are \$40 million per year and land prices are expected to rise at a rate of 7% per year. The opportunity cost of capital is 13%, inflation

54. math

I have a math question that goes like this: There are 500 light that have on and off switches. One person goes and turns all the lights on. The second person switches the lights from 2,4,6,8...and so on. THe 3rd person switches 3,6,9,12....and so on. This

I started having trouble on part (c), and I need to know this before I can go onto the other problems. Plz help! The parabola shown at the right (no picture, sorry) is of the form y=x^2+bx+c. The graph's y-intercept is (0,2), the axis of symmetry is -2.5

56. CHEMISTRY

What is the true meaning of dimerize and trimerize - neither of these words are found in any dictionary and hence, are not actually in use: scientific jargon perhaps, but not proper English. Also, if it is in proper use, in the UK, is it spelt dimerise &

57. Early Childhood Question

Mrs. Ruiz began reading "Arthur's New Puppy." At one point she stopped reading and asked the children what they would do with the puppy. She accepted all their suggestions and wrote them on the board. Mrs. Ruiz was using ________ to help her students think

58. Chem

Bob Pursley, With regards to a question posted by john on Tuesday, January 30, 2007 at 6:14am: How is it that you used 650 degrees C + 273 K when the question asks to presume it stayed gaseous down to 0 degrees C and to use this 0 degrees C for the answer?

59. Maths

Given that arg((z-1)/(z-2i)) = pi/4 describe the locus of P and sketch this on an argand diagram. Show that the point (1,3) lies on this locus. I know it is an arc subtended from the points (0,2) and (1,0) but I do not know how to find the centre of the

60. math

-4x^2(3x^2-x+1) Multiply it term by term, and I will, or someone will check you.

61. English

Please diagram the following sentence: The nickname for the state of Virginia is "Mother of Presidents." My grandaughter just called and wanted to know what was the verb in the above sentence. "is" is the verb in that sentence. nickname (subject) is (

62. SPORTS

What does these colleges have in common "concerning SEC basketball" ..Samford, Georgia, Marshall, Illinois State, Murray State, Cincinnati, UTC,Kent State, Western Kentucky and Wake Forest and Wisconsin-Milwaukee?

63. ununhexium

What is the highest fluride of Uuh? Here is a web site for the periodic table. Look up element number 116. The chemistry of Uuh should be similar to those of S, Se, Te, Po etc. http://www.webelements.com/ I get it as Uuh2F6 but i'm not sure if the valency

64. Hamlet

How do the characters of Laertes and Fortinbras highlight Hamlet's fatal flaw of inaction? Check the character analysis at this site. http://www.sparknotes.com/shakespeare/hamlet/ also check the character analysis at

65. science

How does a tornadoe form? This site has a great explanation and diagrams. http://www.weatherwizkids.com/tornado.htm

66. eth

Wow, im currently in an cultural diversity class and I have feeling the individual who originally posted this question is one of my class mates. I agree that this assingment regarding orientalism and prejudice is extremly fuzzy. I'm trying to figure out

67. Shavez - writing

What kind of people are good role models? This site will give you some ideaS. http://en.wikipedia.org/wiki/Role_model

68. Health

Why do people say that we should have a big breakfast and a small dinner? Thank you for using the Jiskha Homework Help Forum. Think about your car and filling it up with gasoline, etc. before you take a long trip. You need energy to run on as you begin

69. Calculus

can someone please prove the difference rule to me? d/dx[f(x)-g(x)]=d/dx f(x)- d/dx g(x) plz help

70. area/length/volume

How are length, area, and volume related in terms of the three dimensions of space? and How is it possible for objects of the same volume to have different masses? #2 Gads! Think of a cup full of steel marbles and a cup full of cotton balls. ummm, ?

12.

72. Chemistry

I need to take some following samples of these: *a hydrocarbon w/a molecular mass greater than 100 g/mo *something w/ L-carvone or D-carvone in it *a non-electrolyte that dissloves in water *something w/a pressure greater than 2.o atom *a proton donor can

73. Science

How many calories do 12-14 year olds need daily? What food should be eaten every day? What is the maximum and minimum amount of calories daily for 12-14 year olds? The maximum and minimum number of calories for young teens depends upon the gender and

74. English essay again

"It was a hospital for gravely ill children, and he had to watch his friends in the ward die, one after the other. During his stay

75. Chemistry

Why is the colour of the light emitted by an element in the gaseous state characteristic of the element? Various elements absorb some wavelengths while letting others move on. Since this is not my area of expertise, I searched Google under the key words

76. chemistry

addtional information: the diameter of the oil film on the water is 40cm^2 see my post.

77. Mechanics

What force accelerates a 3kg mass at a rate of 4m/s^2? Assuming this is on smooth surface with no frictional force Force = mass x acceleration F = 3 x 4 F = 12N If there is a frictional force will have to look at the acceleration in the opposing direction

78. Mechanics

What is the formula for time and displacement. Or where on the inet can I find a list of mechanics formulae? I am not allowed to post internet sites but if you go to google and search SUVAT the first option has a list of all the formulas you should need

79. chemistry

Can you help me with these please? In general, is the boiling point of a polar liquid likely to be higher or lower than that of a nonpolar liquid of about the same mass? What, if any, is the correlation between electronegatively and reactivity? Thanks in

80. Organic Lab

I have to come up with my own procedure for reducing vanillin, to vanillyl alcohol. Help please! I know I have to use NaBH4 but that is about it!

81. math

-4x^2(3x^2-x+1)=-12x^4+4x^3-1x^2 *Is this correct.? The last term should be -4x^2

82. math

sqrt3x^5y^14 To simplify: sqrt(3 x^5 y^14) The square root of x^4 is x^2. The square root of y^14 is y^7. Can you determine what to do now with those hints? I hope this will help.

83. english

in his plays william shakespeare wrote a great many phares that have stood the test of time. see whether you can rearrange the letters below to discover shakespeares phares still used today. a)d t o h i n i a van_s_e_ i_t_ _h_n _ir hint: its what hamlet's

84. CHEMISTRY

I am given a list of apparatus, liquids & solids and am trying to convert aluminium selenide from solid to geseous states does the following sound correct?... Aluminum selenide (in the round-bottomed flask) reacts with water (coming from addition funnel

85. Chem

Is this true? The molar mass of nitrogen gas is 14.0 g. Nitrogen occurs in nature as N2

86. the play hamlet

in his plays william shakespeare wrote a great many phares that have stood the test of time. see whether you can rearrange the letters below to discover shakespeares phares still used today. a)d t o h i n i a van_s_e_ i_t_ _h_n _ir hint: its what hamlet's

87. questions

what falls but never breaks? what breaks but never falls? night/day