# Zack

Popular questions and responses by Zack
1. ## Chemistry

The equilibrium constant (Kp) for the interconversion of PCl5 and PCl3 is 0.0121: PCl5 (g) ↔ PCl3 (g) + Cl2 (g) A vessel is charged with PCl5, giving an initial pressure of 0.123 atm. At equilibrium, the partial pressure of PCl3 is __________ atm. I have

2. ## Physics Problem

A runner hopes to complete the 10,000m run in less than 30 minutes. After exactly 27 minutes, there are still 1100m to go. The runner must then accelerate at 0.20 m/s^2 for how many seconds in order to achieve the desired time? I get 80.9 but I know that

3. ## math

The 1st,5th,13th term of an arithmetic sequence are the first 3 terms of geometric sequence with a common ratio of 2. If the 21st term of the arithmetic sequence is 72, calculate the sum of the first 10 terms of the geometric sequence.

4. ## space/astronomy

Rank the objects based on the strength of the gravitational force that would be felt by a spacecraft traveling at a distance of 10 AU from the center of each of the objects, from weakest to strongest. 1)red giant mass: 1Msun radius: 100Rsun 2)sun 3)white

5. ## Physics

The electric field lines surrounding three charges are shown in the figure below. The center charge is q2 = -15.9 µC.

6. ## Science

Heat and pressure deep beneath the Earths surface can change any rock into A) chemical rock B) gemstone C) metamorphic rock D) sedimentary rock

7. ## PreCalc

Find the slope of the radius of the unit circle that corresponds to the given angle. 7π/6 radians

8. ## english

Create an accurate summary of “The Cold Equations” that details the important events of the story. Provide your answer in three to five sentences. Can someone help me with this please?

9. ## Physics

An average family of four uses roughly 1200 liters (300 gallons) of water per day. (One liter = 1000 cm^3.) How much depth would a lake lose per year if it uniformly covered an area of 50 square kilometers and supplied a local town with a population of

10. ## Precal

If sin (theta) = sqrt5 / 3 and cos (theta) = 2 / 3 which of the following is tan (theta)?

11. ## math

Kayla needs to have \$560.00 to buy a new laptop. She already has \$200.00 in the bank. Each month she will add \$45.00 to her bank account. How many more months until she has enough money to buy her laptop?

12. ## math

2) Sven sells hamburgers at a ballpark. He earns \$7.50/hour, plus \$0.40 for each hamburger he sells. b) How many hamburgers must Sven sell to earn \$100 in a 6.5 shift? How many hamburgers must Sven sell to earn \$100 in a 6.5 shift?

13. ## Math

The population, in millions, of a city t years after 2000 is given by the function P(t) = 2.9 - 0.008t. Which statement is true? A. The population is increasing by 8,000 people per year. B. The population is decreasing by 8,000 people per year. C. They

14. ## geometry

Assume that lines that appear to be tangent are tangent. O is the center of the circle. Find the value of x. Figures are not drawn to scale. m

15. ## 4th grade math help

Explain how the variable B has two different values in the two equations 6 - B = 5 b = 1 B + 5 = 15. B = 10 Thanks!

16. ## Physics

How would one determine the percent uncertainty in theta and in sin of theta for the following: 1) theta = 15.0 degrees +/- 0.5 degrees 2) theta = 75.0 degrees +/- 0.5 degrees I'm not sure whether I divide or use some kind of formula.

17. ## physics

A 270 caliber hunting rifle fires an 8.5 g bullet, which exits the gun barrel at a speed of 980 m/s. What impulse does the burning gunpowder impart to the bullet? If it takes 2 ms for the bullet to travel the length of the barrel, what is the average force

18. ## math

The height of a baseball (h) in meters (t) seconds after it has been tossed out a window is given by the equation h= -5t^2 + 20t + 15. A boy shoots at the baseball with a trajectory of h= 3t +3. Will the paintball hit the baseball? If so at what height and

19. ## Math

My divisor is 9, I am greater than 7 times 9, I am less than 8 times 9,my remainder is 7,what dividend am I ?

20. ## Math

Hannah made 0.7 of her free throw in a basketball game,abra made 9/10 of her free throws,dena made 3/4 of her free throws,who was the best shooter and explain why you say so

21. ## Math

Amita decides that she wants the molds to have a square base.How many of the possible molds can she use?

22. ## Chemistry 12

Solid phosphorous is found in two forms: white phosphorous (P4) and red phosphorous (P). White phosphorous is the standard state. The enthalpy of the formation of red phosphorus is -17.6kJ. When 32.6 g of white phosphorous reacts to form red phosphorous.

23. ## Algebra 2

Simplify sqrt80 -3 Sqrt63 - sqrt125 - sqrt175

24. ## Ela Help!!!!!!!!!!!!!!!!!!!!!!!

what does Vegetarian - that's an old Indian word meaning lousy hunter mean?

25. ## Physics

A disk with a rotational inertia of 7 kgm^2 rotates like a merry-go-round while undergoing a torque given by (5+2t)Nm. At time 1s, its angular momentum is 5kg m^2/s. what is its angular momentum at 3s? I can't figure out how to start this problem.

26. ## Statistics

True or False, In simple linear regression analysis, if the error terms exhibit a positive or negative autocorrelation over time, then the assumption of constant variance is violated.

the sum of eighty-nine and a number

28. ## Precalculus

A pole sits on top of a tall building an observer on ground 17 m away from building finds the angle of elevation to the base of the pole to be 30 degrees and the angle of elevation to top of pole to be 45 degree. Find height of pole to nearest tenth. Draw

29. ## math

if a man jobs 3 1/2 miles in 3/4 of an hour, how far can he jog in one hour?

30. ## physics

To warm up for a match, a tennis player hits the 56.0 g ball vertically with her racket. If the ball is stationary just before it is hit and goes 5.40 m high, what impulse did she impart to it?

31. ## Math

If f(x) = -3x + 8, find f(5)

32. ## Math

An automobile dealership uses CODE = 1 for new automobiles, CODE = 2 for used automobiles, and CODE = 3 for separate accessories. A salesman’s commissions are as follows: on new automobile, 3% of the selling price but a maximum of \$300; on used

33. ## math

A bag is filled with green and blue marbles. There are 101 marbles in the bag. If there are 25 more green marbles than blue marbles, find the number of green marbles and the number of blue marbles in the bag.

34. ## chemistry

Ba(OH)2(aq) + HCl(aq) BaCl2(aq) + H2O (g) Consider the unbalanced equation above. What is the concentration of the original hydrochloric acid solution if 18.0 mL of the acid reacts with 45.5 mL of 0.280 M barium hydroxide?

35. ## Genetics, HELP!!!

Planet X, a recently discovered planet, contains life forms that have double-stranded DNA as the genetic material. The DNA on Planet X is transcribed into RNA which is translated into protein. Planet X DNA contains only two bases: guanine (G) and cytosine

36. ## PreCalc

Find the equation of the line in the xy-plane that goes through the origin and makes an angle of 1.2 radians with the positive x-axis.

37. ## Physics

what is the schwarzschild radius of a black hole with a mass of 1.68x10^43kg

38. ## Math 115

A manufacture has been selling 1400 television sets a week at \$480 each. A market survey indicates that for each \$24 rebate offered to a buyer, the number of sets sold will increase by 240 per week. a) Find the price p(x) of each television as a function

39. ## Math 115

The manager of a large apartment complex knows from experience that 90 units will be occupied if the rent is 444 dollars per month. A market survey suggests that, on the average, one additional unit will remain vacant for each 6 dollar increase in rent.

40. ## Math 115

A fence is to be built to enclose a rectangular area of 320 square feet. The fence along three sides is to be made of material that costs 6 dollars per foot, and the material for the fourth side costs 14 dollars per foot. Find the dimensions of the

41. ## Science

Why is photosynthesis an example of a chemical reaction, and why is it classified as endothermic?

42. ## Physics

The road runner drops a boulder from a 53 meter high building. When the block is 14 meters above the ground, the 2 meter tall Wiley Coyote looks up and sees the boulder. How much time does he have to get out of the way?

43. ## English

I think this is C if not Which analogy would best go with this one? branch:tree:: A. flower:garden B. teo:three C. tentacle:octopus D. near:far

44. ## English

Would this be D if not Which analogy would best go with this one? A:Z:: A. girl:mother B. weight:pounds C. truth:lie D. prologue: epilogue

45. ## Algebra

How many hands of 5 cards can be made from a standard deck of cards such that each hand contains exactly 1 red card and 4 black cards?

Prove the following: sin(x+y)sin(x-y) = cos^2 (y) - cos^2 (x)

47. ## Writing

Compare how beaver stole fire and stealing fire from Zeus are the same

48. ## Chemistry

given: 25.9 kJ + 1/2 H2 + 1/2 I2 => HI how much energy is needed for the reaction of 4.57x10^24 molecules of iodine, I2, with excess hydrogen, H2?

49. ## Math

use the unit circle to prove that tan(x/2) = (sin(x))/(1+cos(x))

50. ## math

how do you write the number words for 0.03. Is it three hundredths.(2)and the number words for 0.76,is it seven tenths,six hundredths

51. ## Ms. Sue help!!!

Is 87 rounded to 90 or 85? I have to round to nearest fifth

52. ## Ela Help!!!!!!!!!!!!!!!!!!!!!!!

Which sentence is better? Warren had a newspaper business and was one of the United States Senate. Warren had a newspaper business and he was one of the United States Senate.

53. ## Veterans Help!!!

what are the reasons to help a veteran?

54. ## Science plz help

Igneous rock is produced by volcanoes. What do you know about the activity on Earth during the time the oldest layer of rock was produced?

55. ## trig

Suppose that the point P(13,-30) is on the terminal side of the angle theta in standard position. What is sin(theta)? Give your answer to the nearest thousandth

57. ## math

the area of a trapezoid is 45 square centimeters. the bases of the trapezoid are 10 centimeters and 8 centimeters what is the height of the trapezoid?

58. ## Chemistry

All the following species are best described by writing at least two Lewis structures EXCEPT a. O3. b. SO2. c. d. e. SO3. Explanation thanks

59. ## algebra 1

(1,3) and (-2,-4) is m= 1/2

3+6x

61. ## Algebra 1

-5 [54-(99-18)] -5[54 +99 +19] -5 [ 153+19] -5[172] -860 f(x)=2x²-5x How can I simplify -860 to fraction? I know something like - 860/100

62. ## Algebra 1

x+9y=8 (1) x=3-9y (2) x (3-9y)+9=8 3x -9y +9y=8 3x = 8 x= 2.6 Is this correct?

63. ## Chemistry

What is the energy of an electron in the 2s orbital of a hydrogen atom?

64. ## Science

I'm having trouble figuring out what the independent and dependent variables are in the following experiment: 1.

65. ## Algebra

You invest \$4000 in an account paying 4.1% continuously compounded interest. How much will you have in 8 years

66. ## algebra

A subset of a given set may contain no elements, all the elements of the given set, or some of the elements of the given set. How many subsets can be found in {a,b,c,d,e,f,g}?

67. ## Social Studies

The people have very few rights and are not free to own and operate businesses. Which statement is most likely true of the country in which these people live? (1 point)

68. ## Online behavior

sorry my friend went to far but yeah we well never say bad language on this app again and we wont be rude and behave better and not come on this app again please forgive us never again but its okay

69. ## finance

A 10-year bond with an annual coupon rate of 8%. The bond has face value of \$1,000 and makes semiannual interest payments. If you require a 12% nominal yield to maturity on this investment, what is the maximum price you should be willing to pay for the

70. ## math

im so confuzzled..... Salim and Medha are comparing results from a 2-day lab experiment. On Monday, Salim’s results showed that 0.907 of the particles were charged while Medha’s results showed that 88% of the particles were charged. On Tuesday,

71. ## math

Exits on an interstate are numbered consecutively. The distance between Exit 12 and Exit 13 is 2.7 miles. The distance between Exit 13 and Exit 14 is 0.9 mile farther than the distance between Exit 12 and Exit 13. The distance between Exit 13 and Exit 15

72. ## georgia history

what was the main reason for British and colonization of north America? A) to find gold B) to spread Catholicism C) to increase wealth through mercantilism D) to build a strong alliance with the spanish

73. ## Rate of current and time

A ship travels downstream for 36 miles and then makes the same return trip upstream. The trip downstream took 3/4 of an hour less then the trip upstream. If the rate of the current is 4mph find the rate of the ship in still water and the time it takes to

74. ## Math

A recatangular pen is to be made with 120 feet fencing. The pen is divided into 4 equal parts. And an existing property fence will be used for one long side. 1) If x represents the width of the fence express its area A(x) in terms of x 2) Determine the

75. ## Funny question

I'm just curious to know are there any incentives or point system for answering questions here? Like what drives people to? Hobby, getting paid, bored or something else? Does this site have the same structure as ya4oo answers? If so, I kind of get it then.

76. ## Distance across ocean

3 engineers decide to measure the distance across a small area of the ocean. Mojo and Norah are on opposite sides of the ocean. Ken is on land 4.1 miles away from mojo and 6.3 miles from Norah. If the angle formed at kens point is BCA is 37 degrees what is

77. ## Maximum area.

A recatangular yard is to be made with 120 feet fencing. The yard is divided into 4 equal parts. And an existing property fence will be used for one long side. If x represents the width of the fence exeorsss its area A(x) in terms of x Determine the

78. ## Precalc

A ship travels downstream for 36 miles and then makes the same return trip upstream. The trip downstream took 3/4 of an hour less then the trip upstream. If the rate of the current is 4mph find the rate of the ship in still water and the time it takes to

79. ## Dimensions of wall

Width of a wall is 4 inches less then the length. The border that surrounds the wall is 2 inches wide and has an area of 240 square inches. What are dimensions

80. ## physics

A 0.300 kg air-track glider moving at 2.20 m/s bumps into a 0.800 kg glider at rest. a.) Find the total kinetic energy after collision if the collision is elastic. b.) Find the total kinetic energy after collision if the collision is completely inelastic.

81. ## Science

I have looked and I can not find the definition for acquired traits I'm looking for the def. part of speech & synonym Please help. Zack

82. ## eastern michigan

A pole-vaulter just clears the bar at 4.24 m and falls back to the ground. The change in the vaulter's potential energy during the fall is -3500 J. What is his weight?

83. ## Math

Jake is walking up hill in the sand. Every step Jake takes he climbs 2 feet up, but slides down 6 inches. How far has Jake traveled if he has taken 8 steps?

84. ## Math

Given the function f(x) = 3x +4 Determine the value of f(x) for the point (-1, f(x))

85. ## Sequences Math

Find the function rule. X = -2, -1, 0, 1, 2. Y = 9, 4, -1, -6 -11. Help please this is too hard

86. ## English

what are two symptoms the author experiences when exposed to perfume?

87. ## social studies

1. How important is cooperation to the success or failure of the canning cooperative?

88. ## math

jessica depoists 3000 in the bank. her money doubles in 12 years. how much was her intrest rate per year(assume annual compounding)

89. ## Algebra 1

A firework is launched from a cliff overlooking the ocean. The elevation of the firework shell, in feet above sea level, t seconds after launch is given by the expression -16t^2+157t+63. How high is the top of the cliff, in feet above sea level. We just

90. ## Maths

A fair coin is tossed 5 times. If X is the discrete variable the # of tails obtained, a) Draw the probability distribution . b) Find P (X

91. ## Genetics!!

What is the function of a eukaryotic promoter sequence?

92. ## Math

For a specific type of machine part being produced, the diameter is normally distributed, with a mean of 15.000 cm and a standard deviation of 0.030 cm. Machine parts with a diameter more than 2 standard deviations away from the mean are rejected. If

93. ## Geometry

X is a point 7cm from the center of circle O with radius 9 cm. AXB is a chord of the circle such that AX= 2 XB. Find the length of AB.

94. ## Math

What is 29x47 in expanded algorithm

95. ## physics

A 550.27 N force is moving a 396.46 kg block at a constant velocity across a wooden plank. What is the kinetic friction force?

96. ## physics

A 19.62 kg block is sliding down a 34.52 degree incline at a constant velocity. What is the mu k of kinetic friction between the incline and the block?

97. ## Physics

A solid ball is released from rest and slides down a ramp that makes an angle of 50 degrees with respect to the horizontal. a) What is the minimum coefficient of static friction between the ramp and the ball for no slipping to occur? b) Would this

98. ## Math

A chemist wants to create a solution that is 24% acid. How many liters of a 40% acid solution must be added to 50 liters of an 18% acid solution to obtain this 24% acid mixture?

99. ## Alaniz

An airplane is flying at an altitude of 4000 feet and descends at a rate of 200 ft./m determine whether the altitude is proportional to the number of minutes. Explain your reasoning?