# Questions Asked onMarch 4, 2007

1. ## Physics

When jumping straight down, you can be seriously injured if you land stiff-legged. One way to avoid injury is to bend your knees upon landing to reduce the force of the impact. A 75 kg man just before contact with the ground has a speed of 7.0 m/s. (a) In

2. ## chemistry

If there are 80 milligrams of a radioactive element decays to 10 milligrams in 30 minutes then what is the elements half life in minutes? Ok i narrowed it down to either 10 or 30...but im rly confused so if u could help it wuld be grea 80 40 1 min 20 2 min

3. ## physics

A cart of mass 340 g moving on a frictionless linear air track at an initial speed of 1.2 m/s undergoes an elastic collision with an initially stationary cart of unknown mass. After the collision the first cart continues in its original direction at

4. ## Chem

An important process for the production of acrylonitrile C3H3N is given by the following reaction 2C3H6 + 2NH3 + 3O2 --> 2C3H3N + 6H2O A 150 -L reactor is charged tot he following partial pressures at 25 C

5. ## Math Question

Which one of the following pairs of triangle must be similar? a) two isosceles triangles with congruent vertex angles b) two right triangles c) two scalene triangles with congruent bases d) two obtuse triangles a) if the two vertex angles are the same then

6. ## Chemistry

1. Use standard entropies and heats of formation to calculate delta-G of formation at 25° C for a) cadmium(II) chloride (s) b) methyl alcohol, CH3OH (l) c) copper(I) sulfide (s) My problem is that I don't know how to calculate delta-G of formation. I know

7. ## chem

Can someone check this for me? Predict which reactions are spontaneous: a) Zn(s) + 2H+(aq) --> Zn+2(aq) + H2(g) b) CaCO3(s) + 2H2O(l) --> Ca(OH)2(s) + H2CO3(aq) c) CH4(g) + O2(g) --> CO2(g) + 2H2O(g) d) Ag+(aq) + Cl-(aq) --> AgCl(s) I said a) and c) were

The spring constant of a toy dart gun is 4442 N=m. To cock the gun the spring is compressed 1.5 cm. The 8 g dart, fired straight upward, reaches a maximum height of 26 m. The acceleration of gravity is 9.81 m/s2 : Determine the magnitude of the energy

9. ## Probability help!?

I have a bag of 20 m&m's. 6 are red; 7 are blue; 4 are green; 3 are yellow. if I took one out, what is the probability of picking yellow??? Help. t.y. Pr yellow= waystogetyellow/total= 3/20 Is there a way to illustrate this? thank you. (for some reason, I

10. ## Chemistry

For my homework the question is... What is the half life of polonium 214 if a 1 gram sample decays to 31.25mg after 820 seconds? Im not sure how you arrive at the answer, my friend says the answer is 5 but were not sure how to do it..thanks for any help u

11. ## Math

Can someone give me a website on examples of box-and whisker plots? I have to construct a plot for the following set of number: 0.16,0.08,0.27,0.20,0.22,0.32,0.25,0.18,0.28,0.27 I don't have a clue on how to do this. Thanks in advance. I searched Google

12. ## Geometry

Given quadrilateral ABCD,ABllDC, diagonal AC. we can prove that angle 1= angle 2, but cannot prove angle 3=angle4 Why is this. What must be true about the sides of the Quadrilateral in order to prove that angle 3 is congruent to angle 4? My answer: The

13. ## math ,confused

The question is : Bath towels sell for \$13.25 each, while hand towels sell for \$4.50 each. Theresa buys some of each type of towel for a total of \$62.25. If she spends \$17.25 more on hand towels, how many of each type does she buy ? oh never mind I found

14. ## Chemistry

A mixture of chromium and zinc weighing .362 g was reacted with an excess of hydrochloric acid. After all the metals in the mixture reacted 225 mL of dry hydrogen gas was collected at 27 C and 750 torr. Determine the mass percent Zn in the metal sample.

15. ## Math Question

If two sides of a triangle have lengths 4 and 9, then the length of the third side may be any number a) less than 13 b) greater than 5 but less than 13 c) greater than 4 but less than 9 d) greater than 5 I suggest you draw this. It is not d, nor a. it is

16. ## Physics - Rotational Mechanics

The combination of an applied force and a constant frictional force produces a constant total torque of 35.8 Nm on a wheel rotating about a fixed axis. The applied force acts for 5.95 s. During this time the angular speed of the wheel increases from 0 to

A block of mass 2.62 kg is kept at rest as it compresses a horizontal massless spring(k = 141 N=m) by 15.3 cm. As the block is released, it travels 0.627 m on a rough hori- zontal surface before stopping. The acceleration of gravity is 9.8 m/s2 :Calculate

18. ## social studies

why Mexico encouraged Americans to settle in Texas? Mexico had gotten independence from Spain,but most of the land claimed north of the Rio Grande was sparsely populated, and the US population was moving west. The idea Mexico had was to populate it quickly

19. ## Chemistry

ok i need to figure out how a balanced reaction of a fuel cell would look like. you know a source of hydrogen power. http://auto.howstuffworks.com/fuel-cell.htm

20. ## physics-circular motion

the turntable of a record player rotates at a rate of 11 1/3. A record with a radius of 15cm is being played. a punk kid throws a piece of gum that lands right on the edge of the record. What linear distance in meters does the gum travel if it stays on the

21. ## Chemistry Help.......

Sulfuric Acid (H2SO4) is a strong acid, which dissociates when dissolved in water according to the following equation: H20SO4(aq)-> 2H+(aq) + SO4 2- (a) A 0.21g sample of sulfuric acid is dissolved completely in sufficiebt water to make 0.25litre of the

22. ## English

Hi, I'm writing an essay on how Hamlet is a participant of hypocrisy. Can anyone help me write a thesis statement. My points are that his father tells him to avenge him, but Hamlet takes a long time to do it, how Hamlet says he loves Ophelia but is the

23. ## Math

If two angles of one triangle are congruent to two angles of another triangle, these triangles must be a) scalene b) similar c) congruent d) isosceles Dont all traiangles have 180 degrees? So if two angles were congruent, what about the third? I still

24. ## Chemistry

Ok, in this question, the drops is throwing me off totally, can someone help! A nationally known company markets a product called "cleaning vinegar" that is not designed for human consumption. What is the mass percent of acetic acid in this product if 25

25. ## Chemistry

Hey i was wonderingg for my science homework i don't understand how to do this problem. It says: Plutonium 239 can be produced by bombarding uranium 238 with alpha particles. How many neutrons will be produced as a product of each reaction. write out the

26. ## geometery

Can you solve this problem: Identify the letter of the choice that best completes the statment or answer the question. Note: Since there is no symbol on the keyboard for the right angle sign I will use the greater than sign(

27. ## climate graphs

i need a graph of the climate in Italy NOW !! my homework is due in tomorrow! Thank you for using the Jiskha Homework Help Forum. Here is the site and you can pick the city: http://www.mytravelguide.com/travel-tools/climate-graphs/Italy.php Climate graphs

28. ## Math

I need help with this question: Estimate the product by rounding to the nearest one 6.38 times 18.716 I said on my assignment 120 and my teacher marked it wrong. She said it's 114, and I donot see how it's 114. Any input, would certainly be welcome. Thank

29. ## Health

My dog all of a sudden has a small bright red lump on her front left leg. I have no idea what it is, and I'm kind of worried. It might just be a scab or something, but I don't know. Does anyone know what it could be? Thank you for using the Jiskha Homework

30. ## fischer esterification

which alcohol and carboxylic acid would produce benzyl isobutyrate by Fischer esterification? and which alcohol and carboxylic acid would produce isobutyl benzoate by fischer esterification? Since this is not my area of expertise, I searched Google under

31. ## Chem.....

Methanol, CH3OH, is produced on an industrial scale from carbon monoxide and hydrogen. At the temperatures used, gaseous methanol is formed according to the following thermochemical equation: CO(g)+ 2H2(g) CH3OH(g) H = -90Kj 1. State Le Chateliers

32. ## us history intro and conclusion

i posted earlier about my DBQ for my us history class, and i just need to know how i should go about opening and closing what i am saying. it's the only part i have trouble on. heres the question again: In what ways and to what extent did constitutional

33. ## math rate

15 chapters in 5 days - I already know the unit rate is 3 - I have to give the rate and unit rate. I don't know how to figure out the rate. Can someone please help me? rate is 15 chapters/5 days unit rate is 3 chapters/day

34. ## accounting for investments

Can someone check my answers. -For each of the following eight situations, select the best answer concerning accounting for investments: (A.) Increase the investment account. (B.) Decrease the investment account. (C.) Increase dividend revenue. (D.) No

35. ## Physics - EM spectrum

Here's the question: which part of the electromagnetic spectrum has a refractive index of 1.45 in glass? I've attempted to tackle it with v = frequency x wavelength and refractive index = light speed in vacuum / light speed in material but without

36. ## math rate

what would be the unit rate - 15 chapters in 5 days Take 15 chapters and divide by 5 days. Unit rate would be 3 chapters per day. I hope this helps and is what you were asking.

37. ## physics

Sound does not travel through a vacuum. How do we know that light does? Explain how you can see ordinary nonluminous classroom objects. Light? Through what medium does starlight reach us? We see nonluminous objects mainly with reflected light.

38. ## (Home) Economics

Using supply and demand analysis, comment upon whether a free market in university education will always lead to higher charges for law at Cambridge than for sociology courses at new universities. Consider how many people will apply to law school (a

39. ## Math- HELP

How do I Find the first and third quartiles, Q1 and Q3, of the following set of numbers? 13,4,12,16,8,14,8,3,10,8 order the data: 3,4,8,8,8,10,12,13,14,16 Quartile I ends at 8 The quartile II ends at 9. quartile III ends at 13 The calculation of the

40. ## Biology

Where RNA is present? in cytoplasm or nucleus or both of them. Thank you for using the Jiskha Homework Help Forum. I'd begin with the information found on Wikipedia: http://en.wikipedia.org/wiki/RNA (the basics)

41. ## sCiEnCe

Can you define speed, motion, constant speed and average speed? And can you get me there formulas? Ex-Distance over speed THANKS MUCH!

42. ## Can anyone tell me what i could add?

“Six months at sea! Yes, reader, as I live, six months out of sight of land …” Herman Melville, wrote in the preface of his book Typee. From his life to his death, he wrote many great novels, books, and poems. From best sellers to American classics

what does third person limited mean? Third person limited describes a book in which the narrator tells the story in the third person. He knows only his own feelings and thoughts, but describes the actions and words of other characters. For more

44. ## History

What happened in FLorida in 1909? http://www.fws.gov/policy/029fw3.html

45. ## english

From the poem "Thanatopsis" by William Cullen Bryant: What is the universal fact about death? What specific comforts does nature give us, both in life and in death? Give specific examples. According to Bryant, how should we approach death? I need help

46. ## Chemistry

I have drawn Lewis structures for hydrogen cyanide and cyanogen. I need to state the noble gas (for each element) whose electron configuration is attained in the Lewis structures. Can anyone help as I am quite confused! Many thanks Previous posts have

47. ## chemistry

i have had enough,and got no hair left,i need to find the structural formula for ill try my best to explain CH2=CH-CH-OH WITH A CH3 UNDER THE SECOND CH.+CH3-CH-C WITH A CH3 UNDER THE FIRST CH ,A DOUBLE BOND FROM THE C TO O AND A SINGLE BOND TO OH UNDER THE

48. ## BobPursley..here it is:

Problem 1: (x-2)/(3x+4) - 6x/(x+1) What I did: Common denominator is: (3x+4)(x+1) (x-2)(x+1)/(3x+4)(x+1) - 6x(3x+4)/(x+1)(3x+4) [(x-2)(x+1) - 6x(3x+4)] / (x+1)(3x+4) (x^2 - x - 2 - 18x^2 - 24x) / (x+1)(3x+4) x^2 - 18x^2 = -17x^2 -x - 24x = -25x (-17x^2 -

50. ## can some edit my intro! thanks!

World war one was a war from 1914 to 1918, it is also know as the Great War and War of the Nations. It involved many countries such as Great Britain, France, Russia, Belgium, Italy, Japan, the United States, and other allies defeated Germany,

51. ## Herman Melville

I nead help getting info on Herman Melville for a report for Enlish. Please Help. Does anyone Know about Herman Melville at all? See information in response to your later post. Please do not have multiple posts with the same question. Repeating posts will

52. ## physics

In a game of pool the cue ball strikes another ball of the same mass and initially at rest. After the collision the cue ball moves at 3.50 m/s along a line making an angle of 22 degrees with its original direction of motion. and the second ball had a speed

53. ## math

10m/11p.44p/20k.15k/8m we are multiplying and dividing rational expressions. can ne1 help? I have no idea what you need. Your first line makes no sense. i know, it doesn't make any sense to me either...it's fractions 10m/11p times 44p/20k times 15k/8m. we

54. ## homework help

I noticed that the people who asked for questions that need help with spanish have not been answered..when people who have asked questions after them have already..this concerns me that the people on this website help with the subjects they know and don't

55. ## math

what are your feelings about math, rate your math anxiety, and describe what coping mechanisms might be helpful to you and your I like math. What matters is what YOUR feelings amd "coping mechanisms" are.

56. ## religion

what are the simularites and differences between jesus and muhammed? http://www.answers.com/jesus http://www.answers.com/mohammed Let us know what you come up with, and someone here will be happy to critique your thinking. =) sites for Mohammad and Jesus -

57. ## math,correction&help

Is this right:if it still needs more can someone help me out what else can i say....thanks why are polynomials important? polynomials are important because the are used to determine and solve the unknowns in equations. Many natural processes can be modeled

58. ## spanish

What is the poem viejita analfabeta about and is the authors opinion of the lady positive or negative? i looked all over but everything online i get is spanish. Thank you for using the Jiskha Homework Help Forum. I'd love to help you BUT, after spending

59. ## Chem

I'm unbelievably stuck on this problem. Any help would be appreciated. Red phosphorous is formed by heating white phosphorous. Calculate the temperature at which the two forms are at equilibrium, given white P: (heat of formation)= 0.00 kj/mol; standard

60. ## Science

What are ruminents?Are they able to digest cellulose? Thank you for using the Jiskha Homework Help Forum. First of all the dictionary will explain "ruminant" for you: Main Entry: [2]ruminant Function: adjective Date: 1691 1 a (1) : chewing the cud (2) :

61. ## French

I'm trying to figure out how you would say "he is being" in French. I know it has something to do with the present participle "étant," but we haven't really gotten very far into this yet in class. Would you say "il est étant" or "il étant?" Ok I found

62. ## english

How do I know when to use lay or lie? Thank you for using the Jiskha Homework Help Forum. Many people use them interchangeably and perhaps some day that will be the norm. As far as English grammar books are concerned: Lay means "to place something down."

63. ## science

it is incapable of producing offspring but some of its kind is born each day? Mules.

x/3-2/3=1/x *Solve the rational below. I really need help. multiply both sides by x. x^2/3 -2x/3 = 1 multiply both sides by 3 subtract three from each side x^2 -2x -3=0 (x-3)(x+1)=0 Then either of the factors can be zero, or x=3 or x=-1

65. ## Math

I'm trying to help my nephew with some homework and am hopeless. Please help with these questions: If 180 calories of heat were added to 50 grams of copper, what would the change in temperature be? (specific heat of copper = .09) What would the temperature

66. ## math

ok, but what happened to the letters? don't they remain part of the problem? also, how does 15k/20k reduce to 4/5? thanks for your help. joshua 15k/20k should reduce to 3/4 because you can take a 5 out of 15 and be left with 3 and take 5 out of 20 and be

67. ## Chemistry

What colour and formula are the iron 2+ & iron 3+ chloride complexes? http://en.wikipedia.org/wiki/Iron(III)_chloride

68. ## math

Some people believe that calculators have eliminated the need to learn the skills required to perform mathematical operations by hand. State your position on this belief, and then support your position with real-life stories or examples I will be happy to

69. ## math,help

Can someone explain to me the reasoning involved in each step when simplifying the fraction 42/56. I had this question wrong in my previous exam...I don't know what i was thinking when answering it......but i like to know what was the actual responce for

70. ## psychology

The major perspective in psychology that views behavior as guided by one's self image and by needs of personal growth is the a. cognitive view b. humanistic view c. psycholdynamic view d. biopsychological view I had already guessed c and that was wrong,

71. ## Social Studies

What is a Topographical Map and what does it show. help me fast please and I'm only in 5th grade so explain so i can understand. These site will help you with this type of map. Then you can go to your own area and find a topographic map.

72. ## bobPursley2...the other one

Problem 2: (x+2)/(2x^2+5x+2) - (x-3)/(2x^2-5x-3) What I did: 2x^2+5x+2 factors are (2x+1)(x+2) 2x^2-5x-3 factors are (2x+1)(x-3) Then: (x+2)/(2x+1)(x+2) - (x-3)/(2x+1)x-3) So the common denominator is (2x+1)(x+2)(x-3) using that combine the fractions. I

73. ## Science..help plz...

Can you define speed, motion, constant speed and average speed? And can you get me there formulas? Example-Distance over speed THANKS MUCH!

*Please solve the rational expression. x^2/x-4 - 7/x-4=0

75. ## Calculus

If you have a geometric alternating series, and you prove that the series is converging by doing geometric series test, and NOT alternating series test, then does that allow you to say that the series converges ABSOLUTELY? Or should you do alternate series

76. ## math - y-intercept

hi, how would we find the y intercept , given slope of 11/2.54 and points (5,1.49). can you show me the steps so i can solve it. tnx y=ax + b where a is slope, b is y intercept. Put the points in the equation... 1.49=11/2.54 (5) + b solve for b. x + y = 1

77. ## math444

x^2/x+3 - 5/x+3=0 *Please solve the rational equation Your non use of parenthesis is annoying and most confusing. I assume you meant x^2/(x+3) - 5/(x+3)=0 multiply both sides of the equation by x+3, and solve.

78. ## where did bob go?

can anyone simplify and multiply the rational expressions 10m/11p x 44p/20k x 15k/8m? and then explain it to me? have patience.

what are the top five enviromental factors that help organizations achieve optimal function? What are examples of them?

80. ## science

describe the difference between a ball-and-stck model and a space-filling model of a compound ? Vanessa--Have you seen a ball-and-stick model and a space-filling model? If so you will know how to answer this. dont give me stupid answers i can on for help

81. ## Chemistry

Surfactants used in Detergents are: 1-Anionic,OR 2-Cationic,OR 3-Non-ionic.Or all of these http://www.sigmaaldrich.com/Brands/Fluka___Riedel_Home/Bioscience/BioChemika_Ultra/Detergents_Surfactants.html

82. ## Bobpursley can you help me with my problems below?

I had problems from yesterday but I still don't get them can you help?do you want me to repost? repost: I cant find them.

83. ## BobPursley3...another one..

Problem 3: 4x/(x+2) - 8/(x-1) What I did: Common denominator is: (x+2)(x-1) 4x(x-1)/(x+2)(x-1) - 8(x+2)/(x+2)(x-1) [4x(x-1) - 8(x+2)]/(x+2)(x-1) multiply the numerator out. 4x^2 -4x -8x-16 4x^2-12x-16 factor 4 out 4(x^2-3x-4) factor 4(x-4)(x+1) and that

x/3-2/3=1/x *Solve the rational below. I really need help. Multiply through by 3x x^2 -2x = 3 And solve. I don't get it... can you explain it more.then I can help you Margie

85. ## Math Help 222

x^2/x-4 - 7/x-4=0 *Please solve the rational expression. multipy both sides by (x-4) then you have x^2-7=0 x= +- sqrt 7

86. ## English

In the Great Gatsby what is Jordan’s Nick’s Daisy’s, and Tom’s motivation, hope, or dream. I haven't read this work. The best suggestion I can make is that you go to one or both of these websites, look up this book, and see if they have insights

87. ## proof by induction

proof by mathmatical induction that the sum of the first n natural numbers is equal n(n+1)/2 It's true for n = 1. Assume that it is true for some n. Then the sum of the first n+1 natural integers can be obtained by dding the last number n+1 to n(n+1)/2.

88. ## Math

How do you factor a polynomial? Using the FOIL method works with some simple polynomials. FOIL stands for First, Outside, Inside, Last. For example: x^2-4x+4 factors to (x-2)(x-2) Check your work by multiplying them all. x times x is first, x times -2 is

89. ## English

Identify the linguistic,political,social,economic,religious in Puerto Rican Americans and Cuban Americans? It looks as if what you need to do is learn how to conduct thorough and effective searches for yourself. That's what research is, and I'm sure that's

90. ## Science

Can you please help me figure out why evaporation is a cooling process and why becoming a solid is a heating process? evaporation absorbs heat from the environment, thus "cooling" the environment. becoming solid is a heating process as heat is moved from

91. ## math,simplifying

can someone help me if possible simplifying this fraction more (2(x-5))/((x+3)(x-3)(x+1)) It wont simplify any more. okay thank you i just tjought that the bottom i could still simplify it by foiling the first two them multiplying with the last

92. ## spanish

What is the difference between a refugee and an immigrant. Also, What is the solution the economic problem of hispanics? Thanks for any help that you may have. Thank you for using the Jiskha Homework Help Forum. When you want to know the definition of a

93. ## Herman Melville

im running out of info. it's all running together. HELP!!! Since this is not my area of expertise, I searched Google under the key words "Herman Melville" to get these possible sources: http://en.wikipedia.org/wiki/Herman_Melville

94. ## english

hy!nedd some help.. need summary of poems goldsmith the deserted village and crabbe the village i've searched the internet but nothing..has anyone read these 2 poems?

95. ## Math -algebra (check plz)

ok say i was trying to find y in this equation 2x + 3y + 6z =4392. I was given x=3789-1.5y , and z = -531. so i did the working and ended up with 7578-3y+3y=7578 . If i do the math correctly ill end up with 0y = 7578 :S im pretty confused, can someone

96. ## English

What's the significance of water in Toni Morrison's Beloved? How can you relate that to the importance of history in the novel? Thank you for using the Jiskha Homework Help Forum. Here are some sites to help you: 1.

97. ## science

explain why a substancew with a network structure has a high melting point ? High is a relative term. What is high? coudnt u give me a better response Think what holds a network together? Bonds? Bonds must be broken to melt a solid. thank u

98. ## math,algebra,help

can someone explain to me why (3)/(5) and (27)/(45) are equivalent fractions. If you simplify 27/45 by dividing the numerator and the denominator by 9 you will get 3/5. 27/25/9 27/25*1/9=3/5 3/25=3/5 5*3=3*25 15=75 75/15=3 If u multiply 3/5 by 9/9 you get

99. ## English

Identify the lingustic, political,social,economic, religious for the Mexican Americans?

y+2/y=1/y-5 *Please solve the rational equation. Done the same way as the previous post.

Good evening. Thanks for all of your help so far. I posted a question on wednesday 28 Feb @ 11:55 pm that you answered by I am not sure of how to tackle the problem. This is what I came up with so far. Mass of Puck A m1 = 0.021 kg Mag. of init. veloc.of

102. ## math3333

y+2/y =1/y-5 *Please solve the rational equation I am not certain if the right term is 1/(y-5) or the right side is 1/y -5

103. ## Math

What's 1/3 of 12 Marbles? What's 2/3 of 12 Marbles? If 8 Children go on a picnic, 6/8 of them wear jeans. How many wear jeans? what is 1/3 * 12/1 ?

104. ## Strategy

what skills and temperaments do you believe are needed for a successful career in planning? Thank you for using the Jiskha Homework Help Forum. Hopefully one of the sites below will have what you are looking for: