marissa

Most popular questions and responses by marissa
1. Chemistry

Consider the reaction 2H2O(g) → 2H2(g) + O2(g) ΔH = +483.60 kJ/mol at a certain temperature. If the increase in volume is 42.7 L against an external pressure of 1.00 atm, calculate ΔU for this reaction. (The conversion factor is 1 L · atm = 101.3 J.)

2. Physics - Electric Field

Find the electric field at a point midway between 2 charges of +40.0e-9 C and +60.0E-9 C separated by a distance of 30.0 cm. My work: q1=40E-9 q2=60e-9

3. science

if you wanted to consult the geologic time scale for when the first vertebrates evolved, where would you look?

4. College Chemistry

Balance this equations for redox reactions in basic solution. Fe(OH)3(s) + OCl- ¨ FeO42- + Cl-

5. fibers and fabrics

Which one of the following is the most complete and accurate definition of fiber? A. A stringy substance from plants B. The hair of an animal C. Man-made threads and yarns D. Basic raw material from which fabric is made 2. An example of a natural fiber is

6. Home economics

List 10 careers in home economics

7. Algebra

Can someone please explain how to do these problems. 1)write a polynomial function of least degree with intregal coefficients whose zeros include 4 and 2i. 2)list all of the possible rational zeros of f(x)= 3x^3-2x^2+7x+6. 3)Find all of the rational zeros

8. ap biology

What barriers might hinder the acquisition of plasmids?

9. Chemistry

At 20 degrees celcius the vapor pressure of toluene is 22 mmhg and that of benzene is 75 mmhg. Assume an ideal solution, equimolar in benzene and toluene. At 20 degrees celcius what is the mole fraction of benzene in the vapor in equilibrium with this

10. Chemistry, acids and bases

(a) Find pH and pOH of 1.0 M solution of sodium benzoate, NaC6H5COO. (Ka of benzoic acid is 6.2x10^-5) (b) Calculate pH after 0.205 moles per liter of HCl was added (assume volume does not change (c) Calculate pH after 1.0 moles per liter of HCl was added

11. Physics

while on the moon, the Apollo astronauts enjoyed the effect of a gravity much smaller than that on earth. if Neil Armstrong jumped up on the moon with an initial speed of 1.51 m/s to a height of 0.700m, what amount of gravitational acceleration did he

12. Chemistry

three different liquids are used in a manometer. (a) derive an expression for P1-P2 in terms of ro(a), ro(b), ro(c), h1, and h2 (b) suppose fluid A is methanol, B is water, and C is a manometer fluid with a specific gravity of 1.37; pressure P2=121.0 kPa;

13. Physics

A baseball player slides into third base with an initial speed of 3.8m/s. If the coefficient of kinetic friction between the player and the ground is 0.40, how far does the player slide before coming to rest?

14. Chemistry

Your space ship has docked at a space station above Mars. The temperature inside the space station is 24oC at a pressure of 745mmHg. A balloon with a volume of 425mL drifts into the airlock where the temperature is -95oC and the pressure is 0.115 atm. What

0.350L of 0.160 M NH3 is added 0.140 L of 0.100 M MgCl2 . How many grams of (NH4)2SO4 should be present to prevent precipitation of Mg(OH)2 (aq) ? The Ksp of Mg(OH)2 is 1.8 x 10–11.

16. Chemistry

Based on the balanced equation, C2H4 + 3O2 → 2CO2 + 2H2O calculate the molecules of H2O formed when 135 molecules of O2 are reacted.

17. Physics

A man at point A directs his rowboat due north toward point B, straight across a river of width 100 m. The river current is due east. The man starts across, rowing steadily at 2.50 m/s and reaches the other side of the river at point C, 150 m downstream

18. Calculus

A rectangular tank with a square​ base, an open​ top, and a volume of 4,000 ft cubed is to be constructed of sheet steel. Find the dimensions of the tank that has the minimum surface area. I'm not understanding how to get started and find the

19. physics

A wire tooth brace used by orthodontists. The top-most tooth is protruding slightly, and the tension in the wire exerts two forces at 16 º angle on this tooth in order to bring it back into alignment. If the forces have the same magnitude of 19.5 N, what

20. nutrition

Review the nutrition quality of the items, using what you know about daily values, and ingredients (one of the products must have a health claim). Write a 300-500 word essay on what you have learned.

21. physics

Two charges are separated by a distance d = 5 m. The charge q1 has a charge of q1= 7.0 µC (microcoulombs) and q2 has a charge of q2= 6.8 µC. What is the force between the charges?

22. algebra(check)

I'm pretty sure these are right but I just want to check. 1)Find the 20th term of the arithmetic sequence in which a1=3 and d=7 a.143 b.136 c.140 d.133 answer=b 2)Write an equation for the nth term of the arithmetic sequence -3,3,9,15... a.an=n+6 b.an=6n+9

23. Calculus

Find a formula for a function of the form y=bxe−ax with local maximum at (0.5,0.3679). y=

24. algebra

1)Write the expression 9n^6+7n^3-6 in quadratic form,if possible A.9(n^3)^3+7n^3-6 B.9(n^2)^3+7(n^2)-6 C.9(n^3)^2+7(n^3)-6 D.not possible I'm thinking C on this one but im not sure 2)solve b^4+2b^2-24=0 A.-2,-square root of 6,square root of 6,2 B.-square

25. Physics- Exercise 10

A 500kg pig is standing at the top of a muddy hill on a rainy day. the hill is 100.0m long with a vertical drop of 30.0m. the pig slips and begins to slidedown the hill. What is the pig's speed at the bottom of the hill? Use the Law of conservation of

26. Chem

Which one of the compond are covalent HF RbF LiF NaF

27. Chemistry

When coal is burned, the sulfur it contains is converted into sulfur dioxide. This is SO2 is a serious pollutant, so it needs to be removed before it escapes from the stack of a coal fired plant. One way to remove the SO2 is to add limestone, which

28. physics

A man cleaning his apartment pushes a vacuum cleaner with a force of magnitude 55.8 N. The force makes an angle of 15.3 ◦ with the horizontal floor. The vacuum cleaner is pushed 3.55 m to the right along the floor. Calculate the work done by the 55.8 N

I have to read this and answer these questions for homeowrk-I'm not sure if I did this correctly. Could you please check-I put the reading and then questions and my answers under it-thank uyou for checking-I'm really not sure about my answers-I'm a little

30. Physics

The lower frequency limit for human hearing is usually considered to be 20.0 Hz. (a) What is the speed of sound in m/s if the air temperature is 20.0ºC? (b) What is the corresponding wavelength for this frequency?

31. Organic Chemistry

How would you expect the following series of compounds to compare in behavior for SN1 vs SN2? CH3CH=CHCH2Br CH3CH2CH2Br CH3C(-Br)=CHCH3 on the last one, Br is a substituent of the C and that C is double bonded to CHCH3 Please help! Even if someone could

32. History

The growing popularity of newspapers, magazines, and books in the United States during the 19th century contributed to which of these? The emergence of a uniquely American literary style The expansion of educational opportunities for women and minorities

33. math

A support wire runs from the top of a tower to the ground. If the tower is 1200 feet tall and the wire is attached to the ground 500 feet away from the tower, how long is the support wire?

34. physics

a football punter accelerates from rest to a speed of 8 m/s during the time in which his toe is in contact with the ball (about 0.21 s). If the football has a mass of 0.50 kg, what average force does the punter exert on the ball?

35. Trigonometry

A scientist has 37 grams of a radioactive substance that decays exponentially. Assuming k=-0.3,how many grams of radioactive substance remain after 9 days.

36. English

How would you paraphrase this excerpt from "A Tale-Tell Heart" by Edgar Allen Poe; "I bade them search - search well. I led, at length, to his chamber. I showed them his treasures, secure, undisturbed"

37. algebra

Find 2 consecutive integers, the smaller a perfect cube and larger a perfect square.

38. Health

Gonorrhea is spread through contact with the ________. A. Anus, !@#\$%^&, Mouth, Skin B. !@#\$%^&, Anus, Mouth, !@#\$%^& C. !@#\$%^&, Skin, !@#\$%^&, Anus D. Mouth, !@#\$%^&, !@#\$%^&, Fingers I think it's B?

39. biology

A dominant gene A produces wire-haired texture in dogs. Its recessive aamllele a produced smooth hair. Cross the heterozygous wire-haired dog with homozygous smooth-haired dog. List the genotype and phenotype ratios of all the possible offspring.

40. dressmaking

Mrs. Shotto was once one of your regular customers, but she hasn't asked to have any garments made in approximately one year. You note she has lost weight. She would like you to make her a special silk blouse to replace a favorite blouse that has worn out.

41. algebra

I'm pretty sure these are right but I just want to check. 1)Find the 20th term of the arithmetic sequence in which a1=3 and d=7 a.143 b.136 c.140 d.133 answer=b 2)Write an equation for the nth term of the arithmetic sequence -3,3,9,15... a.an=n+6 b.an=6n+9

42. algebra(check)

1)Find a1 in a geometric series for which Sn=300,r=-3,and n=4 a.15 b.15/2 c.-15 d.1/15 answer=a 2)Find the sum of the infinite geometric series n=1 at the bottom of the sigma notation 20(-1/4)n-1 on the right side a.25 b.80/3 c.16 d.does not exist answer=c

a rock is dropped from a 20.0m bridge falls into the river below. a.)at whqat velocity does it strike the water? b.)how much time did the rock take to reach the water?

44. spelling

analogies for couldn't wouldn't as green is to ?

45. Physics

Microwaves with λ = 1 mm are incident upon a 10 cm slit. At a distance of 1 m from the slit, what is the width of the slit's image? The answer is supposed to be 10 cm. I can't seem to get that though. Can someone explain?

46. algebra

1)Find the sixth term of the geometric sequence for which a1=5 and r=3 a.1215 b.3645 c.9375 d.23 answer=a 2)Write an equation for the nth term of the geometric sequence -12,4,-4/3,... a.an=-12(1/3)n-1 b.an=12(-1/3)n-1 c.an=-12(-1/3)-n+1 d.an=-12(-1/3)n-1

47. Chemistry

Potassium permanganate, KMnO4, a common oxidizing agent, is made from various ores that contain manganese (IV) oxide, MnO2. The equation shows the net reaction for one process that forms potassium permanganate 2MnO2+2KOH+O2=2KMnO4+H2 What is the maximum

48. english

Which type of faulty logic appears in this sentence? Dr. Bishop has never performed a surgery before, so he must not be equipped to be a good surgeon.

49. Physics

OK, so I'm having some serious problems with this one question. It's on relativity. Here it is: Calculate the mass of a proton (m0 = 1.67E-27 kg) whose kinetic energy is one sixth its total energy. How fast is it traveling? THANKS!!

50. algebra(reiny)

Hey thanks for all your help but you kinda confused me on a few: 1)Determine whether f(x)=-5x^2-10x+6 has a maximum or minimum value and find that value A.minimum -1 B.maximum 11 C.maximum -1 D.minimum 11 and you said the function opens up, so there is a

51. spelling

what is the answer to this analogy? must start with the letters scr, spr, str, or thr. couldn't:wouldn't ; green ????also for fifteen: five: nine ???

52. Science

I'm in 6th grade and I need help for my science project. I don't even know what to do. Any fun science projects for 6th graders?

53. algebra

1)Use Pascal's triangle to expand (w-x)^5 2)Use the binomial theorem to find the third term in the expression of (n-2p)^6 3)Which is NOT a counterexample to the formula 1^2+3^2+5^2+...+(2n-1)^2=n(2n+1)/3 A.n=3 B.n=2 C.n=1 D.n=4 is it C thanks:)

54. Chemistry

What is the maximum mass of cobalt (II) phosphate that will precipitate from a solution prepared by adding an excess of K3PO4 solution to 100.0 mL of 5.0 M CoCI2? Sorry for all the confusion with different names we are working in a group and its easier to

55. Math

A bicycle trail is 7miles and 880 yards long.How many total yards is the bicycle trail

56. Calculus

How do you use imlicit differentiation to differentiate e^(xy)? I have the problem "use implicit differentiation to find dy/dx. e^(xy)+ x^2 - y^2 = 10. I've gotten to the point whereI have d/dx(e^(xy)) + 2x - 2ydy/dx = 0, but I can't go any further because

57. Chemistry

Write a conversion factor that could be used to convert between moles of methane and moles of hydrogen

58. Chemistry

Potassium permanganate, KMnO4, a common oxidizing agent, is made from various ores that contain manganese (IV) oxide, MnO2. The equation shows the net reaction for one process that forms potassium permanganate 2MnO2+2KOH+O2=2KMnO4+H2 Explain why the oxygen

59. Physical chemistry

100g of water at 30.0C is mixed with 150g of water at 85.0C. What is the final temperature of th mixture assuming no heat is gained or lost during the mixing process?

60. algebra

I'm pretty sure these are right but I just want to check. 1)Find the 20th term of the arithmetic sequence in which a1=3 and d=7 a.143 b.136 c.140 d.133 answer=b 2)Write an equation for the nth term of the arithmetic sequence -3,3,9,15... a.an=n+6 b.an=6n+9

61. algebra

I'm pretty sure these are right but I just want to check. 1)Find the 20th term of the arithmetic sequence in which a1=3 and d=7 a.143 b.136 c.140 d.133 answer=b 2)Write an equation for the nth term of the arithmetic sequence -3,3,9,15... a.an=n+6 b.an=6n+9

62. algebra

1)What is the 4x^2=y^2+8y+32 answer= either hyperbola or parabola 2)The graph of which equation is a circle? answer= 5x^2+10x+5y=9 3)Solve the system of equations by graphing x^2+y^2=16 and y= -x+4 answer= (4,0),(0,-4) 4)Find the exact solutions of each

63. Math differentiation

1. y = x^x 2. y = (sin^2xtan^4x)/(x^2+1)^2 3. y = x^(1/x) 4. y = 2^(-x^3) Okay, so I'm pretty sure 1 is done easily: ln y = ln (x^x) ln y = x ln x d/dx ln y = d/dx x ln x y'(1/y) = x(1/x) + ln x(1) = 1 + ln x y'(1/y) = ln x + 1 y' y(1/y) = (ln x + 1)y y' =

64. geometry

One endpoint and the midpoint of a segment are given. Find the coordinates of the other endpoint. Show all your work. A. Endpoint: (-1,9) Midpoint: (-9,-10) Endpoint: _______ B. Endpoint: (9,-10) Midpoint: (4,8) Endpoint: ________

65. Calculus

A rectangle is inscribed with its base on the x axis and its upper corners on the parabola y= 12 - x^2. What are the dimensions of such a rectangle with the greatest possible area?

66. algebra

1)What is the distance between the museum and sailing club.I cant post the graph or anything but I have my numbers right its 53 but I used the distance formula so its either 53 units or the square root of 53 units. 2)Write the equation of the parabola y=

67. Chemistry

A precipitation reaction takes place when a water solution of potassium phosphate, K3PO4, is added to a water solution of cobalt (II) chloride, CoCl2 Write a balanced equation for this reaction

68. Math

What number is 1,000,000 greater than 337,676

69. Accounting

During the week ended May 15, 2013, Scott Fairchild worked 40 hours. His regular hourly rate is \$31. Assume that his earnings are subject to social security tax at a rate of 6.20 percent and Medicare tax at a rate of 1.45 percent. He also has deductions of

70. algebra

1)Find a1 in a geometric series for which Sn=300,r=-3,and n=4 a.15 b.15/2 c.-15 d.1/15 answer=a 2)Find the sum of the infinite geometric series n=1 at the bottom of the sigma notation 20(-1/4)n-1 on the right side a.25 b.80/3 c.16 d.does not exist answer=c

71. algebra

1)Find a1 in a geometric series for which Sn=300,r=-3,and n=4 a.15 b.15/2 c.-15 d.1/15 answer=a 2)Find the sum of the infinite geometric series n=1 at the bottom of the sigma notation 20(-1/4)n-1 on the right side a.25 b.80/3 c.16 d.does not exist answer=c

72. algebra

1)Write an equation for the parabola with focus (1,3)and vertex(0,3) answer= x= 1/4(y-3)^2 2)Write an equation for a circle if the endpoints of a diameter are at (1,1)and(1,-9) answer= (x-1)^2+(y+4)^2=25 3)Which is the equation of a circle with center

73. math

write an equation for the parabola with focus (1,3) and vetex (0,3) See the paragraph Analytic Geometry Equations. You will have a choice of equations, you did not state whether the axis of symettry was parallel to x or y axis.

74. Algebra

State the possible number of imaginary zeros of g(x)= x^4+3x^3+7x^2-6x-13 this is how far Ive gotten:there are 4 zeros,3 positive and 1 negative If you've found four real zeroes, then there are no imaginary zeroes. You can also see that there are no

75. Chemistry

Calculate molarity of KNO3 solution if 69 g of salt are dissolved into 250 mL of solution

76. physics

Two canoeists start paddling at the same time and head toward a small island in a lake. Canoeist 1 paddles with a speed of 1.40m/s at an angle of 45 degrees north of east. Canoeist 2 starts on the opposite shore of the lake, a distance of 1.5 km due east

77. psychics

The lower frequency limit for human hearing is usually considered to be 20.0 Hz. (a) What is the speed of sound in m/s if the air temperature is 20.0ºC? (b) What is the corresponding wavelength for this frequency?

78. Physics

Two arrows are shot vertically upward. The second arrow is shot after the first one, but while the first is still on its way up. The initial speeds are such that both arrows reach their maximum heights at the same instant, although these heights are

79. Math

estimate a 15% tip on a \$42.65 check

80. Algebra

Write the equation of the prpendicular bisector of the line segment AB with endpoints A(1,1) and B(7,5). Write the answer in slope-intercept form.

81. algebra

1)Solve by factoring:5x^2=4-19x answer=-4,1/5 2)Which quadratic equation has roots 7 and -2/3? answer=A A.2x^2-11x-21=0 B.3x^2-19x-14=0 C.3x^2+23x+14=0 D.2x^2+11x-21=0 3)To solve 4x^2-28x+49=25 by using the square root property,you would first rewrite the

82. Chemistry

How many moles of hydrogen from when 10 moles of methane react completely?

83. chemistry

An equilibrium is dynamic. true or false

84. p.e.

a scull is to rowing as a -------- is to yachting.

85. math

Find a polynomial f(x) with leading coefficient 1 and having the given degree and zeros. Each polynomial should be expanded from factored form, simplified and written in descending order of exponents on the variable. For example: (x+5)(x-2) should be given

86. Chemistry

What is the ionization energy (in kJ/mole) of the hydrogen-like ion F8+ ?

87. algebra

how many quarts of pineapple juice should Theo add to a 20% pineapple drink to create 5 quarts of a 50% pineapple juice mixture?

88. Physics

So I'm having some trouble with this problem.. Is there an equation or is it just a ratio? I'm having so many problems with this one! THANKS! What is the minimum thickness of coating which should be placed on a lens in order to minimize reflection of 531

89. algebra(check)

1)Find the sixth term of the geometric sequence for which a1=5 and r=3 a.1215 b.3645 c.9375 d.23 answer=a 2)Write an equation for the nth term of the geometric sequence -12,4,-4/3,... a.an=-12(1/3)n-1 b.an=12(-1/3)n-1 c.an=-12(-1/3)-n+1 d.an=-12(-1/3)n-1

90. math

1)The area A of a triangle varies jointly as the lengths of its base b and height h. If A is 75 when b=15 and h=10,find A when b=8 and h=6 2)Determine the equation of any vertical asymtotes of the graph of f(x)=2x+3/x^2+2x-3 1) Area of a triangle is 1/2

91. Math!!

A square quilt for a child's bed has a border made up of 32 pieces with an area of x each, and 4 small squares with an area of 1 square inch each. The main part of the quilt is made of 64 squares with an area of x squared each. If the quilt is 4 ft by 4

92. MATH

Use the following time value of money tables to answer the following questions. Assume that the annual rate of interest is 6% for each of the four following problems. i = 6% Time Periods (n) Future Value of 1 Present Value of 1 Future Value of an Annuity

93. Math 222

I am having difficulties trying to do rational expressions. I have to use the words Domain, Excluded Value, Set, Factor, and Real Numbers to show how I got the answer. Can someone please help me solve this one? g^2-6g-55 ___________ g

94. physics

a bag of sugar weighs 5.00 lb on earth. What would it weigh in newton on the moon, where the free fall is one-sixth that of the earth?

95. Nutrion

What types of pathogens? What habits in your food preparation practices do you think might cause these pathogens to grow? What habits can you change in your life to reduce your risk of foodbourne illness?

96. math

Write the equation of the perpendicular bisector of the line segment AB with endpoints A(1,1) and B(7,5). Write your answer in slope intercept form.

97. college

Pretend the program in Senegal had been reducing infant mortality at a rate of 11 % per year. How long would it take for infant mortality to be reduced by 39 %?

98. algebra

1)Find a1 in a geometric series for which Sn=300,r=-3,and n=4 a.15 b.15/2 c.-15 d.1/15 answer=a 2)Find the sum of the infinite geometric series n=1 at the bottom of the sigma notation 20(-1/4)n-1 on the right side a.25 b.80/3 c.16 d.does not exist answer=c

99. algebra

1)A.f(x)= x^2+4 B.f(x)= x^2-4x^2+4x-16 C.f(x)= x^2+4x^2+4x+16 D.f(x)= x^2-4x^2-4x+16 2)A.+-1,+-2,+-3,+-6 B.0,+-1,+-2,+-3,+-6,+-1/3,+-2/3 C.+-1,+-2,+-3,+-6,+-1/3,+-2/3 D.+-1,+-3,+-1/6,+-1/3,+-1/2,+-3/2 4)I don't know what they mean either but this is all it