# Serena

Popular questions and responses by Serena
1. ## Stats

Makers of a new pain-relieving medication claim that it relieves chronic pain faster than the current top-selling pain reliever on the market. A double-blind experiment was conducted in which 10 people who experience chronic pain were randomly selected to

2. ## Math

Rewrite the expression in terms of the first power of the cosine sin^8(x) how do i do this plz help !!

3. ## AP Chem

Reaction 1: NaOH + HCL --> H20 + NaCl delta H of -100.332 kj/mol Reaction 2: NaOH + NH4Cl --> NH3 + H20 : delta H of 358.639 kj/mol Reaction 3: HCl + NH3 --> NH4Cl : delta H of -51.701 kj/mol Use your answers from question 2 above and Hess's law to

4. ## Technology

1. Who is an upstander? A. the person doing the bullying B. the person being bullied C. the person watching the bullying D. the person who tries to stop the bullying** 2. Which of the following is a place where cyberbullying DOESN’T occur? A. chat

5. ## Differential Calculus

The base of an isosceles triangle is 10 feet long and the base angles are decreasing at a rate of 2° per second. Find the rate of change of the area when the base angles are 45°.

6. ## Chemistry

Why does AgCl dissolve in NH3 but AgBr and AgI don't? KSP of AgCl = 1.8 x 10-10 KSP of AgBr = 5.0×10–13 KSP of AgI = 1.5 x 10-16

7. ## Social Studies

Can someone check my responses please? I want to make sure I'm correct before submitting. The * is my response 1. How does the Pledge of Allegiance to the flag of the United States reflect the concept of natural rights? A. The Pledge of Allegiance includes

8. ## Chemistry

I have discovered a new chemical compound with the formula A2B. If a saturated solution of A2B has a concentration of 4.35x10-4M. a) What is the concentration of B2- ions? b. What is the concentration of A1+ ions? c. What is the solubility product constant

9. ## Differential Calculus

A clock has hands 1 and 1 3/5 inches long respectively. At what rate are the ends of the hands approaching each other when the time is 2 o'clock?

10. ## Algebra

Before the final exam, a student has test scores of 72, 80, 65, 78, and 60. If the final exam counts as one-third of the final grade, what score must the student receive in order to have a final average of 76 percent? Thanks!!

11. ## Calculous Pre

A population grows from 11,000 to 15,000 in three years. Enter your answers to three decimal places. Assuming the growth is exponential, find the growth rate and continuous growth rate Growth rate ______ %? Continuous rate _________ %?

12. ## Social Studies

"We hold these truths to be self evident, that all Men are created equal, that they are endowed by their Creator with certain unaliable rights,..." -The Unanimous Declaration of the Thirteen United States of America Which of the following best paraphrases

13. ## Healthcare Statistics

using the following information, determine if the differences between the means are significant medical terminolgy class. Group A = number of word elements remembered by students using flash cards, group B= number of word elements remembered by students

14. ## Chemistry

An atmospheric scientist interested in how NO is converted into NO2 in urban atmospheres carries out two experiments to measure the rate of this reaction. The data are tabulated below. A: [NO]0 = 9.63 × 10-3 M, [O2]0 = 4.1 × 10-4 M t(s)

15. ## Biology

4.0 g of ferrous ammmonium sulphate, FeSO4(NH4)2SO4 6H2O, is used. Since the oxalate is in excess, calculate the theoretical yield of the iron complex. Please help with this question. Thank you.

16. ## Math

1. Which of the following is a possible measure of the area of a square rug? A. 18 square feet B. 24 square feet C. 36 square feet** D. 48 square feet 2. Based on your answer to the precious question, what would the length of one side of the rug be? A. 4

17. ## Chemistry

Assume that the ionic compound CaCl2, separates completely into Ca and Cl ions when it dissolves in water. How many moles of each ion are present in the solution???

18. ## chemistry

what is the hybridization of BrO2+

19. ## history

1. The Inca's huge empire was located in which mountain chain? (1 point) A. Rocky Mountains B. Alps C. Andes----- D. Amazons 2. The Incan people believed their emperor was related to whom? (1 point) A. Cuzco B. Quipo C. the god of Earth D. the

20. ## Precalculus

A rancher wishes to fence in a rectangular plot of land and divide it into two corrals with a fence parallel to two of the sides. If she has 300 yd of fencing available, how large an area can the plot have? This is what I have so far: A=xy 300=2x+3y

21. ## Physics problems

Hi, everyone who is going to read this, thank you for trying to help me, this really means a lot to me, you are saving my behind! Ok, so here it goes: I was wondering if this information is correct; please tell me if it is not A Ferris wheel is a vertical

22. ## Mathematics

A map drawn to scale of 1:50 000 with the actual distance between two points is 4.5km.Calculate the number of centimetres that should be used to represent this distance on the map.

23. ## Algebra 2

If the point P is on the graph of a function f, find the corresponding point on the graph of a given function. P (0,5) y = f ( x + 2 ) - 1

24. ## Math

Convert from base 10 to the indicated base. 2500 to base 14 I got CA8 to the base of 14. Is that correct?

25. ## Calculus

Approximate the area under the curve on the given interval using n rectangles and the evaluation rules (a)left endpoint, (b) midpoint and (c) right endpoint. y=(x+2)^(1/2) on [1,4], n=16 How am I suppose to do this?

26. ## Math algebra

To find the average of a set of test scores we divide the sum of the test scores by the number of test scores. On her first four algebra tests,Paula wests scored 88,92,97,and 96. Write an equation that can be used to determine the grade paula needs to

27. ## Math

A rectangular box has a length of 12 inches and a width 4 inches. The length of the three-dimensional diagonal of the box is 14 inches. What is the height of the box?

28. ## calc

If z = 2cis 60°, find z^4 in rectangular form.

29. ## physics

An object having a net charge of 18.2 μC is placed in a uniform electric field of 790 N/C directed vertically upward, i.e. in the direction opposite gravity. What is the mass, in grams, of this object if it "floats" in the field? (Assume g = 9.80 m/s2.)

30. ## physics

1.7 mol of an ideal gas which starts at 1.6 atm and 50 o C does 2.0 kJ of work during an adiabatic expansion. What is the final volume of the gas?

31. ## physics

A container of volume 14.2 cm3 is initially filled with air. The container is then evacuated at 0oC to a pressure of 32 mPa. How many molecules are in the container after evacuation if we assume that air is an ideal gas?

32. ## Math

A 12-foot ladder is set up 5 feet from the base of a building. How far up the building does the ladder reach? Round your answer to the nearest tenth of a foot.

33. ## history

3. All of the following aided in the decline of the Incan Empire EXCEPT (1 point) A. being conquered by the Mayans. B. Francisco Pizzaro's trap that helped capture and kill the Incan emperor and his men. ---- C. that the Spanish had superior weapons. D.

34. ## physics

The position of a 0.43 kg object attached to a spring is described by [x = (0.49 m) cos(1.25πt)] a) What is the amplitude of oscillations in m? b) What is in meters/second the maximum speed of the oscillating object? Answer in meters/seconds . c) Find in

35. ## Math 10

Hello, Is there easiest and simplest way to do this question? "A baseball is thrown from the top of a building and falls to the ground below. The height of the baseball above the ground is approximated by the relation h = -5t2 + 10t + 15, where h is the

rosa wants to buy a computer desk that originally cost \$650. It has been marked down to a new price of \$520. What is the percent off?

37. ## history

3. All of the following aided in the decline of the Incan Empire EXCEPT (1 point) A. being conquered by the Mayans. B. Francisco Pizzaro's trap that helped capture and kill the Incan emperor and his men. C. that the Spanish had superior weapons. D. that

38. ## physics

an object slides off a roof 10 m above the ground with an initial horizontal speed of 5 m per second. the time between the object's leaving the roof and hitting the ground is 1.4s. how far does it land from the wall?

39. ## physics

"Calculate the internal energy for the air in human lungs after a regular inhalation. You find this volume discussed in the context of the spirometer (textbook p. 203). Hint: treat air as an ideal gas with the molecular mass M = 29.00 g/mol " Not sure the

40. ## Trigonometry

An airplane is 48 miles due north of a town. An airport is 29 miles North-West of the town. It is determined that the airplane is 34 miles from the airport. On what bearing should the pilot fly to get to the airport? Please show work if possibly, I'm

41. ## diameter/kg

What is the mass of water required to fill a circular hot tub 3.4 m in diameter and 1.4 m deep? Answer in units of kg.

42. ## physics

If 842 J of heat is needed to increase the temperature of ethane gas (C2H6) in a 15 litre container from 237 K to 400 K, how much gas is in the container

43. ## Math

The difference between two numbers is 45. Three times the larger number less five times the smaller number equals 75. What are the two numbers?

44. ## Physics

A block of mass 11.2 kg slides from rest down a frictionless 24.0° incline and is stopped by a strong spring with a spring constant 31.3 kN/m (note the unit). The block slides 8.90 m from the point of release to the point where it comes to rest against

45. ## physics

Find the work for an isothermal expansion of 3.08 mol of an ideal gas at temperature of 18oC from pi = 4.55 atm to pf = 3.32 atm.

One tap can fill a barrel in 3 minutes and another can fill it in 6 minutes. Both taps are turned on together for 1 minute. What fravction of the barrel will be filled in 1 minute?

47. ## Pre-Calculus

Verify the following identity: (sin2x)/sin - (cos2x)/cosx=secx

48. ## chemistry

when 12.76mL of HCl of unknown concentration (but less than the base) are reacted with 15mL of 3.254M NaOH, 1.68kJ of heat are released. What is the molarity of the HCl solution?

49. ## trigonometry

Point P (8, -4) is on the terminal arm of angle theta What quadrant would this be in? Cosine?

50. ## physics

Two masses are connected by a light string passing over a frictionless pulley as shown on Figure. The M2= 6.1 kg mass is released from rest at height h = 2.8 m . We are given that M1=2.7 kg and I, the moment of inertia of the pulley is I = 0.198 kg m2 and

51. ## Healthcare Statistics

Given the following p values, which would be considered more significant? p ¡Ü 0.3 p ¡Ü 0.02 p ¡Ü 0.25

52. ## Science

A.) A runner is jogging at a steady 6.7 km/hr. When the runner is 3 km from the finish line, a bird begins flying from the runner to the finish line at 20.1 km/hr (3 times as fast as the runner). When the bird reaches the finish line, it turns around and

53. ## Algebra 1

While playing a game, Rachel pulls two tiles out of a bag without looking and without replacing the first tile. The bag has two colors of tiles--black and white. There are 10 more white tiles than black tiles. a. Write and simplify an expression that

54. ## Chemistry

So I am trying to understand in molecular terms the solubility of NaCl in water. So there are intramolecular forces that are mostly ionic between the ions, creating this partial positive, partial negative substance. And the intermolecular forces are also

55. ## Physics

In a horizontal spring-mass configuration, the position of the 0.52 kg mass is described by [x = (1.09 m) sin(2.70t)] a) What is in meters the amplitude of these oscillations? b) What is in m/s the maximum speed of the mass under these conditions? c) What

56. ## physics, math, science

a soccer ball is kicked on the ground at 8m/s. another player is standing 30 m away. if she needs to intercept it at 20m - how much time does she have and how fast must she run?

57. ## Chemistry

Do pipettes blow up like balloons when they are heated. Why or why not?

58. ## Magic Thesis Statement

Hi! I'm writing an essay about how women act according to male or female domination. Could you please look at my magic thesis and tell me if my why is well written. Thanks! By examining the gender context during Trujillo's regime, one can see that some

59. ## Grammar

Which sentence is grammatically correct? Most of the European population was peasants. or Most of the European population were peasants. Thanks!!!

Insert parentheses to make this sentence true. 3*8+6 squared -8/2=26. My teacher told me I think that the parentheses go around the 3 and last 8. Is that true. How did you do that?

61. ## English Composition I

Argumentive Essay (3 pages) Topic question: Should future educational institutions move toward a specialized educational approach (as seen in technical school), and stray from the traditional well-rounded approach? I need help with: -What keywords would be

62. ## English

Dr. Seuss is an authorwhovis famous for his original and clever children's book

63. ## European History

Can you please explain this quote? "The monarchy of Rome, as it is now, is a pestilence to Christendom." -Erasmus

64. ## MathLog#4

How would you solve for 'a'? (1/a) - (1/b) = c would you use the LCD???

65. ## math

a pari of shoes is on sale for 10% off the original price. If the sale price is \$14.40, what was the original price of the item?

66. ## English

Why does Gene not have an interest in Brinker in the book A Separate Peace?

67. ## physics

At a picnic, a Styrofoam cup contains lemonade and ice at 0 degree C. The thickness of the cup is 2.0*10^-3m, and the area is 0.016m^2. The temperature at the outside surface of the cup is 35 degree C. The latent heat of fusion for ice is 3.35*10^5 J/kg.

68. ## Physics

A solid sphere of mass 2.07kg rolls up an incline with an inclination angle of 24.40°. At the bottom of the incline, the center of mass of the sphere has a translational speed of 2.80m/s. a) What is in J, the linear kinetic energy of the sphere at the

69. ## Physics

Consider the rods plus disc system shown in the Figure. The rod has a length L =0.50 m, and mass M = 0.270kg. The large disc has a radius of R = 0.130m and mass m=0.810kg. The second disk should be treated as a point mass of 0.405kg. It is glued to the rod

70. ## Chemistry

The heat capacity of aluminum is 24.4 J/mol times degrees C. How much energy is released when 5.00 g Al is cooled from 50 degrees C to 30 degrees C. a) 2440 J b) 90 J c) 3.7 J d) 488 J I said A, but the answer sheet says that the answer is B. Can someone

71. ## physics

We confirm the concept of the geothermal effect in an alternative fashion to the discussion in the text. We know that the average rate at which heat is conducted through the surface of the ground in North America is 54.0 mJ/(s m2). Assuming a surface

72. ## biology

How did the primordial atmosphere, photosynthesis, oxygen, the ozone layer, and the endosymbiotic theory influence the origin of living organisms?

So do you mean to say....Ferris wheels use motors, therefore meaning that electrical energy is present. Electrical energy from the motor is then turned into kinetic energy. Electricity, generated from a switch and wires, travel through the motor which

74. ## Physical Science 9th grade

Could someone please explain how I do this or provide a link explaining how. I am very confused. 1) a) Name 2 properties of waves that change if the wave changes media. b) Name a property that does NOT change when it changes media. 2) If the wavelength of

75. ## Math comparing

One box holds 16 crayons.Another box holes 24 crayons.Write a sentence using words that compares the crayons in two boxes.

76. ## Math

What is the factorization of... p^3 - 2p^2 -9p + 18?

77. ## Geometry

Find the measure of the angle formed by the hands of a clock at 9:43. Thanks!

Is there any flowers that rhymes with journal??????

79. ## physcis

Two small beads having charges q1 and q2 are fixed so that the centers of the two beads are separated by a distance d shown in the figure. A third small bead of charge q=10.0 x 10-9 C is placed between both charges a distance x from q1. a) If q1 = 31.0 x

80. ## physics

The position of a 0.31 kg object attached to a spring is described by [x = (0.85 m) sin(2.37πt + 0.35)] a) What is the amplitude of oscillations in m? b) What is in meters/second the maximum speed of the oscillating object? Answer in meters/seconds . c)

81. ## Essay Title

Hi. I need help thinking of a title for the essay I am writing. The essay is about the Dominican Republic and Trujillo's regime. Specifically I am talking about how women who accept/deny female stereotypes accept/deny male domination. Can someone help me

83. ## Chemistry

A 16 oz Frappuccino from Starbucks has 54g of sugar. Calculate the concentration of sugar in percent by mass ( 1 oz = 28 g )

84. ## Math

The radius of the larger circle is 9cm. The diameter of the smaller circle is 11cm. Find the area of the shaded region. I don't understand this questions at all please help.

85. ## Calculus

What would the limit be for the following problems? lim (square root (x+3)) x--> 1 I thought it would be 1.4 lim (1/x) x--> 7 I thought it would be 0 or .1 but neither of those show to be correct. Thank you!

86. ## physics

An m=150 g block hits an M= 265 g block initially at rest on a horizontal surface. After impact they stick together and slide 7.47 m before coming to rest. The coefficient of friction between blocks and surface is 0.39. a) What is in m/s the speed of both

87. ## physica

Consider the rods plus disc system shown in the Figure. The rods are identical. They have a length L =0.50 m, and mass M = 0.250kg. The disc has a radius of R = 0.130m and mass m=0.750kg. Both rods are glued to the disk as shown with X = 0.25m. The system

88. ## Cross-Multiply

9. Explain the process of cross-multiplication.

89. ## science

a 1200W machine operates at 120V. what is the resistance of the machine?

90. ## Physics and Dr. Bob

Not be to a nag, I was just wondering (in addition the energy section from my previous post)...in the wheel the electrical energy is present due to the motor. THis is then turned into kinetic energy, from the magnetic field that is created due to the

91. ## Math 10

Algebraically, determine the vertex form of a quadratic relation, if the vertex is at (-1, 2) and the point (1, -10) is on the parabola. Show all of your steps. I know that the formula is y=a(x-h)suared+ k but how do i apply these numbers to this formula?

92. ## Chemistry

Why does a pound of feathers float, but a pound of lead sink? Is it because of how dense each group is?

93. ## European History

Where was this quote said, what impact did it have on society, and what changes were taking place when this quote was said. “I have the feeling that the days of Cicero and Demosthenes are much closer to me than the sixty years just passed.” -Leonardo

94. ## Accounting

Can someone tell me the formula of how to calculate depreciation?

95. ## physics

We consider hemoglobin along a 0.29 m long tube filled with water. The cross-sectional area of the tube is 326 mm2. The diffusion coefficient is 7 x 10^-11 m^2/s A total amount of hemoglobin of 1.22 x 10-12 g is transported in a steady rate along the tube

96. ## CMC220

how each new medium affected news content and delivery, including how people engaged with news and how the media that preceded it adapted their content and delivery. Be sure to discuss newspapers, magazines, radio, TV, and satellite and Internet services.

97. ## acc250

Has anyone done the Sahron Clark, accouting in Peachtree? Just wondering how to enter the supplies on hand, to the adjusted trial balance. confused about this.

98. ## English (Grammar)

Would it be grammatically correct to say "Lastly, the Puritan values of appeasing towards God in every thing they do..." or "Lastly, the Puritan values of appeasing God in every thing they do..." I'm thinking the second one is grammatically correct but am

99. ## Algebra

An asthma medicine is to be prepared from an elixir with a drug concentration of 5 mg/mL and a cherry flavored syrup that is to be added to hide the taste of the drug. How much of each must be used to prepare 100 mL of solution with a drug concentration of