Devin

Most popular questions and responses by Devin
1. Conditional Probability

A certain virus infects one in every 400 people. A test used to detect the virus in a person is positive 90% of the time if the person has the virus and 10% of the time if the person does not have the virus. Let A be the event "the person is infected" and

2. Calculus

In a 21 meter race between a turtle and a hare, the turtle leaves 8 minutes before the hare. The hare, by running at an average speed of 0.5 meters per hour faster than the turtle, crosses the finish line 4 minutes before the turtle. What are the average

3. pre-cal

to find the distance AB across a river, a distance BC= 309m is laid off on one side of the river. It is found that B= 105.4 degrees and C= 12.2 degrees. Find AB To find the distance AB across a river, a distance BC= 309m is laid off on one side of the

4. ELA

What effect does Father’s return have on the Sakane family? A Yuki finds it hard to adjust to having both parents tell her what to do B Yuki’s mother continues to worry about the safety of her family C Ken is relieved that his father will take over as

5. chemistry

A gas has a volume of 50.0 cm3 at a temperature of -73°C. What volume would the gas occupy at a temperature of -123°C if the pressure stays constant?

6. math

Ty needs to cut strips of wrapping paper that are each 9 inches wide.If Ty has 2 rolls of wrapping paper that are 15 feet long, how many 9-inch strips can he cut ?

7. AP Chemistry

What is the structure for PCl3Br2 and 3 isomers?

8. College Algebra

The logistic growth function f(t)= 100,000/5000e^-t describes the number of people, f(t), who have become ill with influenza t weeks after its initial outbreak in a particular community. A) How many people became ill with the flu after the epidemic began?

9. social studies

Describe the governments in Mexico and Central America. i think mexico form of government is a democratic form of government, can somebody please just tell me what form of government central america has. ms.sue can you help me

10. Science

A horticulturist wants a plant that produces flowers with a certain size, color and fragrance but is not aware of any one plant having all of these traits. The quickest way she could achieve her goal would be to apply the process of

11. physics

A 70 kg painter is painting the wall of a building. He stands on a horizontal board of length 4.7 m and mass 15 kg, suspended from vertical ropes attached to each end. If the painter stands 2.0 m from one end of the board, what would the tensions in the

12. Math

A football is kicked into the air. Its height in meters after t seconds is given by h(t)=-4.9 (t-2.4)^2+29. A. What was the height of the football when it was kicked? B. What is the maximum height of the kick? C. How long did it take for the football to

13. chemistry

h2SO4(aq)+2NAOH(aq)--->NA2SO4(aq)+2H2O(L) how to solve this

14. math

Which algebraic expression represents “the difference of 54 and a number”?

15. physics

If a 0.1 kg mass is suspended at rest from a spring near the Earth's surface, the distance that the spring is stretched is measured to be 1.0 cm. What is the spring constant of the spring (remember the MKS units)? A mass of 2 kg is attached to a spring

16. College Chemistry

1 L of N_2_ gas, having a pressure of 2.5 atm, is added 1 L of Ar gas, having a pressure of 3.7 atm, in a sealed, rigid flask. What is the final pressure in the flask?

17. Math

A state lottery requires you to choose 4 cards from an ordinary deck: I heart, 1 club, 1 diamond, and 1 spade in that order from the 13 cards in each suit. If all four choices are selected by the lottery, yo win \$5,000. It costs \$1 to play. Find the

18. College Physics

A person jumps from a window 34 meters high and is caught in a firefighter's net which stretches 0.6 meter. To the nearest m/s^2, what is the magnitude of the person's acceleration in the net?

19. physics

43. A block of mass 2.00 kg rests on a ramp tilted at 25.0°. Coefficients of friction for the block/ramp: μs = 0.300, μk = 0.100. A string passing over a high quality pulley connects the block with a bucket as shown below. The bucket contains sand but a

20. math

why did the indian wear feathers in his hair

21. Physics

A bullet with a mass m=12.5 g and speed v=85.4 m/s is fired into a wooden block with M=113 g which is initially at rest on a horizontal surface. The bullet is embedded into the block. The block-bullet combination slides across the surface for a distance d

22. Chemistry

What is the percentage yield for a reaction if you predict the formation of 21 grams of C6H12 and actually recomvered only 3.8 grams? is the answer 18% 3.8g/21g x 100% pls verify.

23. math

9x-11 3x+43 ____________ L M N the value of x is

24. Physics

(a) How high a hill can a car coast up (engine disengaged) if friction is negligible and its initial speed is 96.0 km/h? (b) If, in actuality, a 750 kg car with an initial speed of 96.0 km/h is observed to coast up a hill to a height 18.0 m above its

25. Chemistry

When a chemist burns ammonia according to the reaction below she finds that the reaction releases heat. (It is exothermic.) 4NH3(g) + 3O2(g) 2N2(g) + 6H2O(g) The enthalpy of the reaction DH = -1267 kJ. What is the enthalpy change (in kJ) when 7 grams of

26. Physics 1 College Level

If D = 3204 meters and d = 1247 meters in the figure, what is the magnitude of the force on the space ship to the nearest MN? Consider all three to be point masses. I'm not even sure to begin with this question. Any help will be much appreciated!

27. Physics 1 College Level

A planet/moon has a mass of 77.89 × 1023 kg and a radius of 7.9 × 106 meters. What is g on the surface to the nearest hundredth of a m/s2? Once again, not really sure where to go with this. Out of the 10 problems I've only had trouble with this and one

28. physics

A pendulum has a length of 1m. What is the period of this pendulum? What is the frequency of this pendulum? You measure the period of a pendulum and get 25s. What is the length of the pendulum?

29. Physics

An Atwood's machine consists of masses m1 and m2, and a pulley of negligible mass and friction. Starting from rest, the speed of the two masses is 3.80 m/s at the end of 3.16 s. At that time, the kinetic energy of the system is 77.0 J and each mass has

30. Spanish

What is wrong with the statement? El va de Miami a Buenos Aires. Esta tomando un vuelo nacional.

31. math

Kim has fraction 1 over 2 cup of almonds. She uses fraction 1 over 8 cup of almonds to make a batch of pancakes

32. Math

When the waiter was asked to slice the 16-inch (in diameter) pizza into exactly 4 slices of equal size, he decided to do so using concentric circles rather than radial slices. Determine the radii of each of the three cuts he had to make.

33. Science

ranging minerals from the hardest to the softest. Chalk, fingernail. steel screw and paper clip

34. Math

a.) Given that f(3)=5 and f'(x)=x/((x^3)+3), find the linear approximation of f(x) at x=3. b.)If the linear approximation is used to estimate the value of f(2.9), will it be an overestimation or underestimation? Show justification.

35. Chemistry

How many milliliters of pure acetic acid (density = 1.05 g/mL) would be required to prepare 1.00 L of the solution?

36. Math

Bank A pays 4.79% compounded monthly, while Bank B pays 4.8% compounded quarterly. Which bank pays more?

37. College Level Physics

A horse pulls a cart with a force of 145 newtons at an angle of 30 degrees above the horizontal and moves along at a speed of 2.5 m/s. How much work to the nearest kJ does the force do in 6 minutes?

38. child development AED 202

develop a presentation for early childhood and middle childhood groups that addresses health issues appropriate for each developmental level

39. Algebra

Jessie needs to rent a truck for two days to move her belongings to college. She can rent a U- Haul for \$35 a day plus 25 cents per mile or she can rent a Budget Rental Truck for \$25 per day plus 32 cents per mile. Write an equation and solve to find out

40. chemistry

A 7.56-g sample of gas is in a balloon that has a volume of 10.5 L. Under an external pressure of 1.05 atm, the balloon expands to a volume of 15.00 L. Then the gas is heated from 0.00 degree C to 25 C. If the specific heat of the gas is 0.909 J/g*C, what

41. Calculus

Graph the following function. Find and state the domain, intercepts, asymptotes, intervals of increase and decrease, local extrema, concavity, and inflections points. F(x)=(x+1)/(square root(x^2+1)) I got so far... Domain: (-infinity, infinity) Intercepts:

42. College Finite

Assume that the student has a cup with 13 writing implements: 7 pencils, 4 ball point pens, and 2 felt-tip pens. In how many ways can the selection be made if no more than one ball point pen is selected?

43. Math

The stopping distance d of a car in feet is related to the speed in mph by the equation d(s)=.02s^2+1.1s Calculate the speed when your stopping distance is: 1.) 51ft 2.) 315.12ft

44. english

Crossword puzzle Substitute lively__________ for boring, "tired" words. Has 7 letters

45. physics

estimate the rotational kinetic energy of earth, assuming it to be a solid sphere of uniform density

46. statistics

To find out what people think, the Gallup Poll selected a random sample of 520 women and 506 men. The pollsters showed them a list of personal attributes and asked them to indicate whether each attribute was “generally more true of men or of women”.

47. math

Please show me the steps to solve this problem: The total shipping weight of two crates is 358 pounds. One crate weighs 124 pounds more than the other. What does eah crate weigh?

48. math

one side of a right triangle has 2cm less than the hypothuse, and 7cm more than the third side what is the lenghnt of each side

49. Physical Sciance

Calculate the density for a rectangular block using the following measurements, Length: 2.70cm, Width:1.10cm, Height: 9.09cm, Mass: 72.17g. Round your answer for density to 2 decimal places. Include the correct unit for density.

50. Economics

In a regression analysis, suppose there is, in fact, no seasonal pattern to sales, and the trend line is estimated using dummy variables to account for seasonality. What effect would this have on the estimation? My guess is that it wouldn't affect the

51. math

If Mark invests \$8000 at 6% simple interest rate, how much money must he invest at an 8% simple interest rate in order for the interest on each investment to be \$500. Assume that the amount of time for both investments is the same.

52. Math Antics

A certain disease has an incidence rate of 0.5%. If the false negative rate is 7% and the false positive rate is 2%, compute the probability that a person who tests positive actually has the disease.

53. math

You get one spin.what is the probability of spinning a number larger than 6 out of 8.

54. Chemistry

A 0.885 M solution of sulfuric acid (H2SO4) is to be reacted with a 0.552 M solution of sodium hydroxide to make sodium sulfate and water. How many L of the H2SO4 solution will react with 0.842 L of the NaOH solution? Give your answer to 3 decimal places.

55. Chemistry

Calculate the total heat (in Joules) needed to convert 1.602 x 101 grams of ice at -1.383oC to liquid water at 8.554 x 101oC. Melting point at 1 atm 0.0oC Cwater(s) = 2.09 J/goC Cwater(l) = 4.18 J/goC delta Hofus = 6.02 kJ/mol

56. Complex Physics Problem

A ladder can fall for two reasons. If it is set too steep and climber gets their mass to the left of the ladder's base, the ladder likely will fall over backwards. If the ladder is set at too shallow of an angle the required force of friction between the

57. college algebra

an executive invests \$29,000 some at 7% and some at 6% annual interest. if he receives an annual return of \$1870, how much is invested at each rate?

58. Calculus

a.) Given that f(3)=5 and f'(x)=x/((x^3)+3), find the linear approximation of f(x) at x=3. b.)If the linear approximation is used to estimate the value of f(2.9), will it be an overestimation or underestimation? Show justification

59. chemistry

The average out door concentration of carbon monoxide ,co at 15 c and 1 atm of pressure is about 900 micrograms per cm^3 . What is this concentration expressed : on ppm scale ? And on the molecules /cm^3scale?

60. Algebra1

A CELL PHONE ORDDERS 500 NEW PHONES FROM A MANFACTURE.IF THE PROBABLITY OF A PHONE BEING DEFECTIVE IS 2.6% PREDICT HOW MANY OF THE PHONES ARE LIKELY TO BE DEFECTIVE.ROUND TO THE NEAREST WHOLE NUMBER

61. Engineering

A 2kg piece of gold metal at 90 C is placed in 5 liters (=5kg) of water at 30 C. Determine the final temperature (Tf).

62. math

Tell whether x and y are in a proportional relationship. If so, find the unit rate. Let y be the temperature x hours after midnight. The temperature is 60∘F at midnight and decreases 2∘F every 12 hour.

63. math

Find the perimeter of the given triangle. Round your answer to the nearest tenth if necessary. ∆ADF, if ∆ADF ∼ ∆BCE, given BC = 17, BE = 9, CE = 12, and DF = 15. ∆BCE is inside of ∆ADF

64. Gaussian Elimination Method

Write the system of equations as an augmented matrix. Then solve for x and y. -3x-y=11 -9x-2y=34 Solution =

65. Homework

A poll was taken of 10,439 working adults aged 40-70 to determine their level of education. The participants were classified by sex and by level of education. The results are shown below. Education Level Male Female Total High School or Less 2023 3264 5287

66. Physics

A baseball is hit at ground level. The ball reaches its maximum height above ground level 3.2 s after being hit. Then 2.7 s after reaching its maximum height, the ball barely clears a fence that is 81.0 m from where it was hit. Assume the ground is level.

67. Physics

A baseball is hit at ground level. The ball reaches its maximum height above ground level 3.2 s after being hit. Then 2.7 s after reaching its maximum height, the ball barely clears a fence that is 81.0 m from where it was hit. Assume the ground is level.

68. practical english

Which of the following sentences contains an italicized word that's used as a predicate adjective? A. Jerry looks ILL today. B. Jerry looks INTO the microscope. C. Jerry looks disdainfully at the pile of laundry D. Jerry looks at the map. Is it c?

69. Math

A math teacher wrote x^2+bx+c=0 on the board and asked students to find the two real roots. Alice miscopied one of the coefficients and found that 1 and 4 were the roots. Andy miscopied a different coefficient and found that -2 and 3 were the roots.

70. chemistry

If the radiicativr decay of nuclear explosion contains 90 Sr , with a half life of 28.1 years how long will it take for 99 of this radioaioot to decay

71. english

Crossword puzzle Try to have_________ in length and form of your sentences. 7 letters

72. College Algebra

Charlie can grade exams in 2 hours. It takes Mark 6 hours to grade the same exams. If they work together, how long will it take for them to grade the exams?

73. physics

A 6.15 kg block slides 1.49 m down a frictionless incline that makes an angle of 60.0° with the horizontal. What is the total work done on the block

74. algebra

how would solve this math question 5/8x - 6 3/8x = 1 1/2

75. algebra

2. As you are leaving the community, you notice another new community just down the street. Because you are in the area, you decide to inquire about it. a. The sales representative here tells you they also have two floor plans available, but they only have

76. algebra

1. Imagine you are in the market for a new home and are interested in a new housing community under construction in a different city. a. The sales representative informs you that there are 56 houses for sale with two floor plans still available. Use x to

77. math

Short projectile motion question A German rocket from the second world war had a range of 3000meters reaching a maximum height of 1000meters. Determine the rockets maximum velocity

78. math

for math test ncca/ equations and inequal

79. Economics

what is a hype song to rap to a economics question. Like this example: search (I'm on econ) on youtube

80. Dynamics

The acceleration of a particle moving along a straight line is inversely proportional to its speed with the constant of porpotionality being k. The body starts from the position s = x0 ^i with initial speed v0. Determine the velocity of the particle as a

81. Physics

A train at a constant 44.0 km/h moves east for 42 min, then in a direction 45.0° east of due north for 17.0 min, and then west for 51.0 min. What are the (a) magnitude (in km/h) and (b) angle (relative to north, with east of north positive and west of

82. Physics

A batter hits a pitched ball when the center of the ball is 1.35 m above the ground.The ball leaves the bat at an angle of 45° with the ground. With that launch, the ball should have a horizontal range (returning to the launch level) of 106 m. (a) Does

83. Physics

A baseball is hit at ground level. The ball reaches its maximum height above ground level 3.2 s after being hit. Then 2.7 s after reaching its maximum height, the ball barely clears a fence that is 81.0 m from where it was hit. Assume the ground is level.

84. science

need a example of the ecosystem cliche

85. chemistry

Lewis dot of free radical cf2cl and hoco

86. chemistry

How many grams of na cl are required to make 500ml of a 0.65 percent w/v

87. algebra

The time it takes you to go 12 miles upstream is 5/4 the time it takes you to go 14 miles downstream. If the current is 3mph, how fast do you go in still water.

88. Math

The letters A,B,and C represent three different digits. Determine the number ABC if ABC + ACB ---------- BCA

89. Algebra 1

9x-8y=42 4x+8y=-16

90. Abstract Algebra

Let H={a+bi a,b is a element R, a^2+b^2=1} be a subset of the non zero complex numbers C*. Prove that H

91. math-ish

What words does tcnaio make unscrambled? Try these: http://www.ssynth.co.uk/~gay/anagram.html http://wordsmith.org/anagram/ http://www.unscramble.net =) action atonic tonica cation

92. Algebra 2

I need help-exam tomorrow! Although it is too late for your exam, in the future, we need specifics to provide help plus time to respond. We are volunteers and are not available 24/7. I hope this helps you in submitting future questions. Thanks for asking.

93. physics

1- a pipe of diamter 1cm carreiers water flowing at 1m/s. the end of the pipe is bplugged and there is a small holeon the top as shown which is 1mm diameter. How high does the water go? *=hole ()____________*___() 2. you're indoors, with a door 1m wide and

94. Chemistry

66.9 g of a substance X dissolves in enough water to make 0.428 L of a 0.68 M solution. Calculate the molar mass of X in g/mol.

95. physics

A plane cruising along at 268 m/s, in straight level flight wants to drops a bomb. He is at a height of 1000m. At what distance should the pilot release the bomb in order to hit his target?

At 2pm the temperature is 22 degrees, by 4am it is negative 7 degrees. We think the answer in the change of temperature is 29 degrees am I right?

At 2pm the temperature is 22 degrees, by 4am it is negative 7 degrees. We think the answer in the change of temperature is 22 degrees am I right?

98. math

what is the exponential form of 1000 * 1000

99. math

How do you solve sqrt(1-(9/x^2))? I know the answer is sqrt x^2 -9/x but I'm not sure how to get the answer on my own. If you could show steps on how to get the answer that would help me a lot!