# Devon

Most popular questions and responses by Devon
1. ## Statistics

Standard Normanl Drill: A. Find the number z such that the proportion of observations that are less than z in a standard Normal distribution is 0.8. B. Find the number z such that 35% of all observations from a standard Normal distribution are greater than

2. ## Chemistry

What is the mole fraction of ethanol, C2H5OH, in an aqueous solution that is 50.0% ethanol by mass?

3. ## chemistry

a solution of 2.5 M weak acid is .52% ionized. what is the Ka value of this acid? ive been stuck on this one for a long time and cant figure out where to even start...if someone could walk me through this itd be great! thanks

4. ## physics

A 905 kg test car travels around a circular track with a circumference of 3.25 km. If the magnitude of the force that maintains the car's circular motion is 2140 N, what is the car's tangential speed?

5. ## pre-calc

A ship travels 200km west from port and then 240km due south before it is disabled. Illustrate this in a vector diagram. Usa trigonometry to find the course that a rescue ship must take from port in order to reach the disabled ship. i don't know where to

6. ## Math

A projectile is fired with an initial velocity of 350 feet per second at an angle of 45° with the horizontal. To the nearest foot, find the maximum altitude of the projectile. The parametric equations for the path of the projectile are x = (350 cos

7. ## social studies

what significant effect did the treaty of paris signed after the french and indian war have on france. A. france had to withdraw to it's empire in central and south america B. france had to allow the british to claim settle the ohio vally C. france lost

8. ## algebra

The Kwon family has a rainwater catchment system they use to water their garden. After 3 days without rain, the depth of water in the tanks is 63 inches. After 5 days, the depth is 57 inches. Write an equation in point-slope form describing the situation

9. ## chemistry

Assume that no heat is lost to the surroundings and calculate the enthalpy involved when 200. mL of .10 M potassium hydroxide and 200. mL of .10 M hydrochloric acid are mixed. Both solutions began at room temperature, 24.5 degrees celsius, and have

10. ## Calculus

A 0.9 ml dose of a drug is injected into a patient steadily for half a second. At the end of this time, the quantity, Q, of the drug in the body starts to decay exponentially at a continuous rate of 0.4% per second. Using formulas, express Q as a

11. ## math

A class of 43 students took an exam. Their mean grade average is 67 and standard deviation is 7. a) how many students should get a C? b) how many should get a B? c) what score is necessary to get an A?

12. ## math

Jordana baked 4 apple pies. she wants to share them equally among 3 neighbors. what fractional part of the pies will each neighbor get?

13. ## physics

A freight train has a mass of 5 x 107 kg. If the locomotive can exert a constant pull of 12 x 105 N, how long would it take to increase the speed of the train from rest to 85 km/h

14. ## Physics

A cylindrical diving bell 4.0m tall, with an open bottom, is lowered to the bottom of a lake on a day when atmospheric pressure is 100 kPa. It is observed that water rises inside the bell to within 1.0m of the top. A)What is the pressure of the air trapped

15. ## math

i don't really know how to go about anwsering this problem: the weight of the eggs produced by a certain breed of hen is Normally distributed with mean 65 grams and standard deviation 5 grams. think of cartons of such eggs as SRSs of size 12 from the

16. ## math

A study to determine whether or not a football filled with helium traveled farther when kicked than one filled with air found that while the football filled with helium went, on average, farther than the one filled with air, the difference was not

17. ## physics

A girls sits on a tire that is attached to an overhanging tree limb by a rope. The girl's father pushes her so that her centripetal acceleartion is 3.8 m/s2. If the length of the rope is 3.3 m, a) what is the girl's tangential speed? b) If the magnitude of

18. ## Chemical Compounds

How can a flow chart help you to name chemical compounds? Some people like to memorize rules and use the analysis of compounds then to apply the rules. CAN YOU HELP ME!!

19. ## physics

Approximate the gravitational force of attraction between a 42.0 kg girl and a 56.0 kg boy if they are sitting 3.0 m apart in physics class.

21. ## trig

it says to verify the following identity, working only on one side: cotx+tanx=cscx*secx Work the left side. cot x + tan x = cos x/sin x + sin x/cos x = (cos^2 x +sin^2x)/(sin x cos x) = 1/(sin x cos x) = 1/sin x * 1/cos x You're almost there. thanks so

22. ## Math

A wheel with radius 2 cm is being pushed up a ramp at a rate of 6 cm per second. The ramp is 520 cm long, and 260 cm tall at the end. A point P is marked on the circle. How far does the wheel travel in one rotation?

23. ## physics

A 25 kg chair initially at rest on a horizontal floor requires 360 N horizontal force to set it in motion. Once the chair is in motion, a 316 N horizontal force keeps it moving at a constant velocity. a) Find the coefficient of static friction between the

24. ## Chemistry

Hydrogen boils at 20K. What is the boiling point of hydrogen on the Celsius scale? K is 273.15 degrees plus the celsius. so take 20(K) and minus 273.15 this would give your answer in celsius thanks.. One more question What is the volume of a board that

25. ## statistics

about what percent of the bags of pet food weigh less than 49.8 lb?

26. ## Math

A bottle of water costs \$1.50. Explain how you would make a graph of four ordered pairs to model the total cost of the water in terms of the number of bottles.

27. ## Physics

A computer hard drive rotates at 5400 revolutions per minute. Starting from rest, what torque will get the hard drive up to that speed in just 150 revolutions? The moment of inertia of the hard drive is 1.3×10^-2 kg·m^2. I know the answer is 2.2 N.m, but

28. ## Math

The sticker price of car is \$15,800. If the sales tax is 8% what is the total cost? Show working

write the oxidation and reduction half-reactions that occur at the anode and cathode, respectively, when MgCl2 liquid is electrolyzed using inert electrodes. HELP PLEASE!!!

30. ## Physics

(the drawing is of a square with each side equaling L and the opposites of each corner are equal to each other, so the mystery corner would be 3I) Four parallel long straight wires are carrying current perpendicular to the page, and the points at which

31. ## Math

At a summer camp there are 60 girls and 30 boys. Twenty percent of girls and 40% of boys passed the swimming test. What percent of the campers passed. Please show working.

32. ## Ms. Sue

Say you make the following assumptions: 1. Afarmer lives on 1 hen per day for a year. (2.)1 hen eats 25 grasshoppers per day (3.)1,000 grasshoppers have a mass of 1 kg (4.) 1 grasshopper requires about 30g of soy beans per year (5.) 1 human requires about

33. ## Economics

A person must decide whether or not to proceed with a particular investment project. If the project succeeds, She will gain \$15 million. If the project fails, she will lose \$3 million. She estimates there is a 20% chance that the project will succeed and

34. ## (Life)

What is a good conflict resolution technique for employees? Talk together. Work it out. Compromise. If you cannot do this, consult your employer. Are you talking about conflict resolution among employees or between employees and employers? Elizabeth's

35. ## physics

An apple (0.100 kg) is thrown vertically upward at a speed of [let x = any whole number between 10 and 20] m/s (from an arm 1.5 m off of the ground). What is the maximum height that the apple reaches? (g=9.8 m/s2)

36. ## chemistry

in regards to electrochemistry, Can Na metal displace Zn2+ in a single replacement reaction?

37. ## Physics

A fossil-fuel power plant that generates 1000MW of electrical power discharges 1600MJ per second as waste heat into the river. A)At what rate(in MW) is thermal energy obtained fromt the burning of coal? B)What is the thermal efficiency(power output/heat

38. ## physics

A tugboat pulls a ship with a constant net horizontal force of 5200 N and causes the ship to move through a harbor. How much work is done on the ship if it moves a distance of 3 km?

39. ## Mathematics

In the universal set (U) reperesents all the students in a class.The set m represents the student who take (Music 3x).The set D represents the students who take (Drama 7+x).If 24 students take Music, calculate The number of students who take BOTH music and

40. ## physical science

can volcanoes form anywhere on earth why or why not

41. ## Math

convert the number to scientific notation. .0000000009

42. ## math

A fitness company surveyed the weights of its 90 costumers. Assume that the weights are normally distrubted with a mean of 162 lbs and a standard deviation of 3.5 lbs. If you select one of its costumers randomly, what is the probability that the costumer's

43. ## Physical science

In my tenth-grade-level physical science class, we're studying heat, and I completely don't get it. I'll read the definition for specific heat over and over, and I still don't understand it. "For all substances, specific heat is a characteristic physical

44. ## trig

it says solve for all real solutions, compute inverse functions to 4 sigfigs. cos^2x=3-5cosx Devon, what grade level are these questions from? I am having the same problems as with your 9:14 post. Please see my partial solution in the post to bobpursely at

45. ## Chemistry

How do i balance this equation? Al+N2---->AlN 2Al + N2 ----> 2AlN

46. ## physicss

What average force is required to stop an 1100 kg car in 9.1 s if it is traveling at 83 km/h?

47. ## Math

The park department planted oak and mapel trees in a 5 to7 ratio. They planted 360 trees. How many mapel did they plant?

48. ## Math

1. Gerald received the following test scores in math class: 76, 86, 89, 81, and 99. What was Gerald’s average test score, rounded to the nearest point?

49. ## algebra

use the quadratic formula to find the roots of the equation. round to the tenths place,if necessary 11x^2-x-3=0

50. ## math

solve 27^2x-1=(1/81)^x

51. ## Math

A bill for a meal is \$10.38 including tax. Find the total cost if the customer leaves a 15% tip.

52. ## Math

A test has 125 items. Each correct answer earns 1point and 65% is a passing grade. If you get 42 answers wrong will you pass? Show working

53. ## Physics

A fish at a pressure of 1.1 atm has its swim bladder inflated to an initial volume of 8.16 mL. If the fish starts swimming horizontally, its temperature increases from 20.0 degrees Celsius to 22.0 degress Celcius as a result of exertion. A)Since the fish

54. ## physics

A 7 kg bucket of water is raised from a well by a rope. If the upward acceleration of the bucket is 1.4 m/s2, find the force exerted by the rope on the bucket of water.

55. ## physics

A small weather rocket weighs 15.5 N. The rocket is carried up by the balloon. The rocket is released from the balloon and fired, but its engine exerts an upward force of 11.0 N. What is the acceleration of the rocket?

56. ## Algebra

x^3-2x^2-9x-2 is greater than or equal to -20. I got (-9+x^2)(x-2)(x-2). That would mean for the first grouping, the answer would be -3 or 3. My book listed them separately. Could I instead go +/- 3? I then got double root of two. But my book says the

57. ## just a ?

What do you think about this" Tragedy of the Commons" Idea? Have you ever found yourself saying these same things? r witnessed someone else behaving this way?

58. ## math

A fitness company surveyed the weights of its 90 costumers. Assume that the weights are normally distrubted with a mean of 162 lbs and a standard deviation of 3.5 lbs. If you select one of its costumers randomly, what is the probability that the costumer's

59. ## Algebra 2

What is the determinant of -2 -3 5 0 15 How you get 15 Use the definition of a determinant. From the first column you take take the element that is in the position of a permutation of 1, from the second you take the element that is in the position given by

60. ## Science

Suppose you are pulling a wagon with th handle at an angle.how can you make your task easier

61. ## Math fractions

A picture frame is 6 1/4 inches wide by 8 inches tall. If a 5 inch by 7 inch picture is to be centered in the frame, what should the right margin be?

62. ## math

If someone had a score of 495/500, What is the mixed number fraction? "I'm confused because if the denominator is bigger than the numerator how can we end up with a mixed number"

63. ## Bus 101

Can someone help me to compare answer for final exams introduction to Business - These are my answers Here are my answers... 1.c 2.a 3.a 4.d 5.c 6.b 7.a 8.b 9.c 10.b 11.a 12.a 13.c 14.d 15.a 16.a 17.a 18.8 19.c 20.b 21.a 22.a 23.d 24.a 25.b 26.d 27.a 28.b

64. ## Physics

A block of mass m = 2.4 kg is released from rest at a height of H = 3.0 m on a curved frictionless ramp. At the foot of the ramp is a spring whose spring constant is k = 317.0 N/m. What is the maximum compression of the spring, x?

65. ## Chemistry

Calculate the energy associated with the photon that would be released when an H electron falls fro the n=3 energy level to the n=1 energy level. show work if possible so I can understand how to do it. Thanks in advance!!!

66. ## Math

what is the surface area of a sphere with a radius of 4.75 units

67. ## Algebra

F) Why is (3x + 5) (x - 2) + (2x - 3) (x - 2) not in factored form? What is the correct final factored form? What is this factoring method called?

68. ## Algebra

4. A customer wants to make a teepee in his backyard for his children. He plans to use lengths of PVC plumbing pipe for the supports on the teepee, and he wants the teepee to be 12 feet across and 8 feet tall (see figure). How long should the pieces of PVC

69. ## Algebra

I'm not sure how to factor x^3-4x is greater than/equal to 0 so that I can find the zeroes. Can you demonstrate, please?

70. ## science

under what circumstances, is it okay to exploit natural area resources for human benefit?

71. ## science

Say you have a million dollars that you can invest into a bank account for 10% interest each year. how much money will you have each year to live off of? If you use more than amount,what happens to your original capital? What happens to your

72. ## Science

I need help to put a terrestrial resource plan together. I have no clue as where to start.

73. ## math

In the set of numbers 2,3,5,7,7,8,10 what is a) the arithmatic mean b) the harmonic mean c) geometric mean

74. ## Math

What is the answear to add. 5. 5/8 7. 2/3 19. 3/4

75. ## precalc

simplify: (x^-2 - y^-2) / (x^-1 - y^-1) i know you have to get rid of the negative powers, but i cant figure out how, any help?

76. ## pre calc

sketch the graph y=abs(x)+2 then sketch over the y=x line.

77. ## research paper

i have to include these questions in my report, and i can't seem to find them anywhere, any help? What influences may China and India have on other Asian countries as their economies begin to emerge on the global scene? What benefits have American

78. ## math

solve the inequality: n^3-7n+6

79. ## Science

How do i find the valence electron for Chlorine.

80. ## science/chemistry

thank you! What is the molar concentration of hydroxide ions in a solution with a pH of 6? Find the concentration of H ions first.. [H+]= antilog -ph Then, find [OH-] [OH-]= 1*10^-14/[H+]

81. ## trig...again

gahh i cant figure this one out either. you have you verify the identity only using one side of the equation: sec^2x*sin^2x+sec^2x=-1 this identity cannot possible be true. on the left side you are adding 2 squared quantities, how can that result be

82. ## Science/Chemistry

How many electrons can occupy a single molecular orbital? and Alumimum is a group 3A metal, Which ion does A1 typically form? I'm thinking Al3+ Your first question depends on the molecule involved and how it is bonded. Hybrid molecular orbits can be

83. ## English

I am having trouble with an analysis of “There is a beauty at the goal of life” I am needing help in identifying the speaker, basic situation and though development, mood, tone, and theme or universal truth.

84. ## math

if \$13.69 is the price of a pair of sneakers after 75% was taken off, what was the original price of the sneakers?

85. ## math

If my dog and cat has a combine weight of 24kg and my rabbit and my dog has a combine weight of 20kg and my cat and rabbit has a combine weight of 10kg.whats the combine weight of my rabbit,dog and cat

86. ## spanish

if someone could help me conjugate these words correctly id really appreciate it!(sorry, I was unable to put accentos) 1. ?Habra alguien que me (comprender)? 2. Querian que tu (ir) a la biblioteca. 3. Tomas fue a la carcel porque (robar)a alguien. 4. Era

87. ## health & safety

Serious violations were issued citing 29 CFR 1910.252(a)(2)(iii)(B) and 1910.252(b)(2)(i)(A). Using the PDCA framework, develop a plan that will correct the deficiencies and ensure that the violations do not recur.

89. ## medical

a. xenology b. morphology c. xenomorphology d.monumentology Which one of the above answers are the study of the form of body parts is called?

90. ## Math

Solve for x: x^2 -2x-4=0

91. ## Math

Pat paid \$35 for a shirt that originally cost \$50. What percent of the original price did the shirt cost? Please show working. I calculated it to be 30% but the answers provided are (a) 40% (b) 65% (c) 70% (d) 85%.........Please Help me

92. ## math

A test has 125 items. Each correct answer earns 1point and 65 percent is a passing grade. If you get 42 answers wrong will you pass? Show working

93. ## Geometry

A kite has diagonals of 16 inches and 23 inches as seen below. What is the perimeter of the kite?

94. ## Science

I have to make a book about Potassium. What are some cool wasy a can make a book from scratch?

95. ## algebra

How do you factor 2w^2+11w-30 ???

96. ## Algebra

2. Biologists want to set up a station to test alligators in the lake for West Nile Virus. Suppose that the costs for such a station are \$2,500 for setup costs and \$3.00 to administer each test. a. Write an expression that gives the total cost to test x

97. ## Algebra

1. The cost, in millions of dollars, to remove x % of pollution in a lake modeled by a. What is the cost to remove 75% of the pollutant? b. What is the cost to remove 90% of the pollutant? c. What is the cost to remove 99% of the pollutant? d. For what

sometimes called the simplepredicate.

99. ## Algebra

M is 5 years older than N. The product of their ages is 84. How old is M?