# rachel

Popular questions and responses by rachel
1. ## mathematics

create a quintic polynomial inequality for which x=-4, x=0, x ≥ 2 is the solution. Justify your answer by solving the inequality using an interval chart. Provide a diagram as well.

2. ## Mathematics

Marianne and faith are upgrading the storage shed in their backyard. the existing shed has the shape of a rectangular prism with dimensions 1 m by 2 m by 4 m. By what amount should they increase each dimension so that the new shed is 9 times the volume of

3. ## Chem

A sealed container holding 0.0255 L of an ideal gas at 0.989 atm and 71 °C is placed into a refrigerator and cooled to 45 °C with no change in volume. Calculate the final pressure of the gas.

4. ## mathematics

Consider the polynomial function P(x) = -x^3 - mx^2 + nx - 5m. The remainder when P(x) is divided by (x-2) is 1 and (x+1) is a factor of P(x). Determine m and n algebraically.

5. ## Mathematics

Unity Games is a company that sells video games. Its revenue last year was modelled by the function g(x)=-4x^4+6x(4x-1)-4 and its revenue this year is modelled by the function f(x)=-3x^2((x^2)-8)-6x-5 where x is the number of video games sold in the

6. ## math

A test had 200 questions .Each correct answer carried 2 marks.Each wrong answer carried -1/2 marks and unanswered question fetched no marks .Ajay attempted all the question in the test and he scored 360 marks.What would his marks be, if for each correct

7. ## Chemistry

3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g) standard enthalpy: -133.5 Find the change in internal energy for this reaction. Enter in kJ.

8. ## Chemistry 12

The molar heat of vaporization of water is 42 kJ/mol. How much energy is released by the condensation of 3.0 g of water? So for water there will just be one mol. I think this is how you do it, but it doesn't match the answer in the worksheet. q=mc delta t

9. ## Physics

Please Help ! A child throws a snowball at a tree and it sticks to the tree. Does this motion defy the Law of Conservation of Momentum? Explain. The Law of Conservation of Energy states: "If there is no net force acting on a system of objects, the total

10. ## Pre calc

sin(θ − ϕ); tan(θ) = 5/12 θ in Quadrant III, sin(ϕ) = − sqaure root 10/10 ϕ in Quadrant IV I tried this numerous times can somone please help me

11. ## physics conservation of momentum

A 0.5 kg ball is thrown horizontally towards a wall with a speed of 10 m/s. The initial velocity is chosen to be the positive x-direction for this question. The ball horizontally rebounds back from the wall with a speed of 10 m/s in the negative

12. ## Chemistry

what is the name for the following coordination compounds or ions? 1. [Al(H2O)6] Br3 2. [Cr(NH3)6] Cl3 3. K3[FeF6] 4. [Zn(OH)4]-2

13. ## statistics

In a survey of 5100 TV viewers, 40% said they watch network news programs. Find the margin of error for this survey if we want 95% confidence in our estimate of the percent of TV viewers who watch network news programs. Hint, find the CI using 1-PropZInt,

14. ## PRE-CAL

Complete the table for the time t (in years) necessary for P dollars to triple when interest is compounded continuously at rate r. (Round your answers to two decimal places.) R=2% t=? tried to plug in as A=Pe^rt since continiously 3=e^.02t ? then take the

15. ## Geometry

A gardener wants the three rosebushes in her garden to be watered by a rotating water sprinkler. The gardener draws a diagram of the garden using a grid in which each unit represents 1 ft. The rosebushes are at (1, 3), (5, 11), and (11, 4). She wants to

16. ## physics

An accelerating voltage of 2.46 * 10^3 V is applied to an electron gun, producing a beam of electrons originally traveling horizontally north in vacuum toward the center of a viewing screen 34.0 cm away. What is the magnitude of the deflection on the

17. ## phyics

A dart leaves the barrel of a blowgun at a speed v. The length of the blowgun barrel is L. Assume that the acceleration of the dart in the barrel is uniform. Find a time that the dart moves inside the barrel. Express your answer in terms of the variables L

18. ## Calculus

Let g and h be any two twice-differentiable functions that are defined for all real numbers and that satisfy the following properties for all x: I) (g(x))^2 + (h(x))^2=1 ii) g'(x)= (h(x))^2 iii) h(x)>0 iv) g(0)=0 a)Justify that h'(x)=-g(x)h(x) for all x b)

19. ## Physics

Suppose that in the same Atwood setup another string is attached to the bottom of m1 and a constant force f is applied, retarding the upward motion of m1. If m1 = 5.30 kg and m2 = 10.60 kg, what value of f will reduce the acceleration of the system by 50%?

20. ## Chemistry

I know how to find half-lives, but I have trouble finding the length of time it would take for the concrentration of X to decrease to Y% of its initial value. For example, this is one of the problems: Methyl isocyanide, CH3NC, isomerizes when heated to

21. ## math

Find x so that QS || PT PQ = 8, QR = 5, RS = 15, ST = x + 3

22. ## Chemistry H

"When you pulled the steel wool apart, you found that the mass was unchanged. When you heated the steel wool, you found that the mass changed. Explain."

23. ## chemistry

A pure copper cube has an edge length of 2.00cm. How many copper atoms does it contain? (volume of a cube = (edge length)^3; density of copper = 8.96g/cm^3 )

24. ## Physics

A barge with mass 1.7×105 kg is proceeding down river at 6.1 m/s in heavy fog when it collides broadside with a barge heading directly across the river. The second barge has mass 2.83×105 kg and was moving at 4.2 m/s. Immediately after impact, the second

25. ## Physics

A child's game consists of a block that attaches to a table with a suction cup, a spring connected to that block, a ball, and a launching ramp. By compressing the spring, the child can launch the ball up the ramp. The spring has a spring constant k, the

26. ## math

A rectangular playground is to be fenced off and divided in two by another fence parallel to one side of the playground. Five hundred and forty feet of fencing is used. Find the dimensions of the playground that maximize the total enclosed area. What is

27. ## Math

Your baseball team has won 6 games and lost 4 games.if the team doesn't lose any more games,how many games must the team win to have a win:lose ratio of 2:1

28. ## Chemistry

What is the hybridization of phosphorous in a P4 molecule

29. ## Geometry

The equation (x + 6)^2 + (y + 4)^2 = 36 models the position and range of the source of a radio signal. Describe the position of the source and the range of the signals.

30. ## pre calc

To measure the height of the cloud cover at an airport, a worker shines a spotlight upward at an angle 75° from the horizontal. An observer D = 600 m away measures the angle of elevation to the spot of light to be 45°. Find the height h of the cloud

31. ## Government

What is meant by “standards of justice have not always been met”? Provide examples of some efforts that have been made to reach the goals of justice at all?

32. ## Physics

A ball is shot from the ground into the air. At a height of 9.1 m, the velocity is observed to be v = (6.6 + 5.7 ) m/s, with horizontal and upward. (a) To what maximum height does the ball rise? m (b) What total horizontal distance does the ball travel? m

33. ## calcius

Determine whether the function is linear, constant, or neither y = x3 - x2 + 8 a. Linear b. Constant c. Neither I think it is neither

34. ## Physics

A small ball rolls horizontally off the edge of a tabletop of height h. It strikes the floor a distance x horizontally away from the edge of the table. (Use any variable or symbol stated above along with the following as necessary: g.) (a) How long is the

35. ## physics

Two very long, straight, parallel wires carry currents that are directed perpendicular. Wire 1 carries a current I1 into the page (in the -z direction) and passes through the x axis at x = +a. Wire 2 passes through the x axis at x = -2a and carries an

36. ## chemistry

Determine the theoretical yield of C when each of the following amounts of A and B are allowed to react in the generic reaction: A+2B-->3C 1) 1mol A; 1 mole B 2) 1mole A; 3 mole B 3) 2mole A; 2 mole B 4) 32mole A; 68 mole B

37. ## Physical Science

A 0.6-g peanut is burned beneath 50 g of water, which increases in temperature from 22degreesC to 50 degreesc. What is the exact food value of the peanut? (Assuming a 40% efficiency)

38. ## Physics

Three vectors are shown in the figure. Their magnitudes are given in arbitrary units. Determine the sum of the three vectors. Give the resultant in terms of (a) magnitude and (b) the angle within the positive x axis.

39. ## science

Four racecars are driving at constant speeds around a circular racetrack. The data table gives the speed of each car and each car’s distance from the center of the track at one instant. Car Speed (m/s) Position (m) A 40 20 B 40 25 C 50 20 D 50 25 Rank

40. ## Physics

The magnitudes of the four displacement vectors shown in the drawing are A = 14.0 m, B = 11.0 m, C = 12.0 m, and D = 25.0 m. Determine the (a) magnitude and (b) direction for the resultant that occurs when these vectors are added together. Specify the

41. ## Physics

1. Two points in a plane have polar coordinates (2.5 m, 30 degrees) and (3.8 m, 120 deg). Determine (a) the cartesian coordinates of both points and (b) the distance between the points. 2. Vector A has magnitude 29 units and points along +y. When vector B

42. ## algebra

Including a 9% sales tax, an inn charges \$127.53 per night. Find the inns nightly cost before tax is added

43. ## chemistry

In the reaction 2SO2 (g) + O2 (g) 2SO3 (g), which change would cause the greatest increase in the concentration of SO3?

44. ## physics

Two hypothetical planets of masses m1 and m2 and radii r1 and r2, respectively, are nearly at rest when they are an infinite distance apart. Because of their gravitational attraction, they head toward each other on a collision course. Note: Both the energy

45. ## Physics

A parallel-plate capacitor is made from two plates 12.0cm on each side and 4.50mm apart. Half of the space between these plates contains only air, but the other half is filled with Plexiglas of dielectric constant 3.40. An 18.0 V battery is connected

46. ## Gen Chem 1

A tanker truck carrying 2.01×10^3kg of concentrated sulfuric acid solution tips over and spills its load. The sulfuic acid is 95.0% H2SO4 by mass and has a density of 1.84g/L. Sodium Carbonate (Na2CO3)is used to neutralize the the sulfuric acid spill. How

47. ## chem

A hot air balloon is filled with 1.51 × 106 L of an ideal gas on a cool morning (11 °C). The air is heated to 103 °C. What is the volume of the air in the balloon after it is heated? Assume that none of the gas escapes from the balloon.

48. ## Math

It takes Kasey 1 2/3 hours to bike the Woodlawn Trail. It takes her 3 5/6 hours to bike the Hammerside Trail. How many times as long does it take Kasey to bike the Hammerside Trail than the Woodlawn Trail ? A. 2 1/6 B. 2 3/10 C. 2 1/3 D. 5 1/2 How to solve

49. ## Physics

A loaded penguin sled weighing 60 N rests on a plane inclined at 20° to the horizontal. Between the sled and the plane the coefficient of static friction is 0.27, and the coefficient of kinetic friction is 0.13. (a) What is the minimum magnitude of the

50. ## calculus

Let P= (V^2)R / (R+r)^2 Calculate dP/dr, assuming that r is variable and R is constant.

51. ## math

how to find the height of a trapezoid with median 12 and area 84

52. ## chemistry

Lead is often found in Earth's crust as several lead compounds. Calculate the mass in kilograms of the amount of each of the following lead compounds that contains 4500kg of lead. 1)PbCO3 (cerussite) 2) PbSO4(anglesite)

53. ## Chemistry

The Haber process developed to produce fertilizer from nitrogen and hydrogen, is governed by the following unbalanced reaction: a N2 + b H2 -> c NH3 . If 10.5 kg of NH3 product is required, how many kg of hydrogen are required if nitrogen is in excess?

54. ## Geometry

TV screens are measured on the diagonal. If we have a TV-cabinet that is 72 inches long and 64 inches high, how large a TV could we put in the space (leave 2-inches on all sides for the edging of the TV)? Round your answer to the nearest tenth.

55. ## science

How would you separate a mixture of small beads, sand, iron filings, salt, and water, using a magnet, filter funnel, filter paper, bunsen burner and a tripod with a bunsen burner? I thought of Filtration, Evaporation, Distillation, Magnetism, and even

56. ## Algebra

Geppetto is a puppet maker. He starts the month with 3 puppets ready to sell, and makes 9 puppets per day. Write an equation to model this situation (use d for days and p for puppets).

57. ## Algebra

After visiting the Titanic, Captain Brain and Mr. Pinky are taking the Alvin submarine back to the surface of the water. They start 1500 meters below the surface of the water, and ascend at 37 meters per hour. Note: under the water is a negative number.

58. ## math

The sum of two numbers is 4 and the reciprocal of one exceeds the reciprocal of other by twice the product of their reciprocals. What is the product of the reciprocals of two numbers? Please help me solving.

59. ## Chemistry

An archeological artifact was subjected to radiocarbon dating. The artifact showed a carbon-14 decay rate of 13.8 disintegrations/ min per gram of carbon. Carbon-14 has a half-life of 5715 years, and currently living organisms decay at the rate of 15.3

60. ## Chemistry

Identify the predominant intermolecular forces between molecules of each of the following compounds: a. CCl4 b. HF c. SO2 d. CH3COOH e. HI

61. ## chemistry

Aqueous silver nitrate reacts with aqeous potassium iodide in a double-replacement reaction to produce a precipitate of silver iodide. If 34.6 ml of 0.563 M silver nitrate are used with 148.4 ml of potassium iodide: a) What molarity of potassium iodide

62. ## chemistry

What is Delta H rxn for the following chemical reaction? H2O(l) + CCl4(l)-> COCl2(g) + 2HCl(g)

63. ## algebra

The Big Screamer Coaster carries 92 people altogether. Some of its cars carry 4 passengers, and the rest carry 6 passengers. There are three less 6-passenger cars than 4-passenger cars. How many 4-passenger cars are there?

A toy rocket is launched form a 3m platform, at 8.2m/s. The height of the rocket is modelled by the equation h=-4.0t^2+8.1t+3 where h is the height, in metres, above the ground and t is the time, in seconds. After how many seconds will the rocket rise to a

65. ## AP Chemistry

The reaction of 5.7 grams of fluorine with excess chlorine produced 7.6 grams of ClF3. What percent yield of ClF3 was obtained? Answer in units of %.

66. ## phyics

Consulting the graph shown in (Figure 1) , determine the object's average velocity over the time interval from 2 to 4 seconds. Express your answer in meters per second to the nearest integer. Position versus time graph for an object traveling with a

67. ## Physics

Speed: A block lies on a horizontal frictionless surface. A horizontal force of 100 N is applied to the block, giving rise to an acceleration of 3 m/s2. What is the speed of the block after 10s? I think I would just multiple the two and put it in terms of

68. ## chemistry

The number of protons in an anion must always be ________ the number of electrons. the same as We can’t tell. less than greater than

69. ## Chemistry

Temperature is a measure of the amount of heat an object contains. T/F

70. ## Math

3 similar shirts and 4 similar jackets cost \$360. 1 such shirt and 3 such jackets cost \$220. Find the cost of each shirt.

71. ## Physics

A certain spring stretches 5.8cm when a load of 38N is suspended from it. How much will the spring stretch if 48N is suspended from it (and it doesn't reach its elastic limit)?

72. ## Physics

What is the spring constant of a spring that stores 25 J of elastic potential energy when compressed by 6.0 cm from its relaxed length?

73. ## Physics

Vector A has a magnitude of 5.00 units, vector B has a magnitude of 9.00 units, and the dot product A·B has a value of 42. What is the angle between the directions of A and B?

75. ## Chemistry(check my work)?

An equilibrium mixture of the following reaction was found to have [COF2] = 0.255 M and [CF4] = 0.118 M at 1000°C. What is the concentration of CO2? 2 COF2(g) ---> CO2(g) + CF4(g) Keq = 2.00 at 1000°C I know I need to put the numbers in the equation so

76. ## Physics

A small m = 2.00 g plastic ball is suspended by a L = 24.0 cm long string in a uniform electric field, as shown in Figure P15.50. If the ball is in equilibrium when the string makes a 18.0° angle with the vertical as indicated, what is the net charge on

77. ## algebra 2

can you answer this question? a store is offering a discount of 30% on a suit. There is a sales tax of 6%. A) using a composition of function, represent this situatio in which the discount is taken before the sales tax is applied. B) using a composition of

78. ## sociology

What is the difference between deviance and nonconformity?

79. ## organic chemistry

how do you increase the yield of triphenylmethanol in a grignard reaction?

80. ## Chem. Again

28: You have a glass of pure water. Are chemical reactions occurring in the water? If so, what are they? If not, explain why not. 29: While investigating the effects of acid rain in your area, you discover a lake that is surprisingly resistant to changes

81. ## Chem

Complete and balance the molecular equation, including phases, for the reaction of aqueous sodium sulfate, Na2SO4, and aqueous barium nitrate, Ba(NO3)2. I don't know how to do this please help

82. ## math

A square 4 inches on a side is cut up into smaller squares 1 inche on a side. What is the maximum number of such squares that can be formed?

83. ## Geometry

A flat screen television is advertised as being 59 inches on its diagonal. If the TV is 13 inches tall, then how wide is the screen?

84. ## Chemistry

For the reaction, calculate how many grams of the product form when 3.2 g of CaO completely reacts. Assume that there is more than enough of the other reactant. CaO(s)+CO2(g)→CaCO3(s)

85. ## physics

a particle executing shm time period t from mean position the time to complete 5/8 oscillation

86. ## chemistry

A metal oxide will form an acid when it is dissolved in water. T/F

87. ## AP CALC. AB

A particle moves along a line so that at time t, where 0

88. ## algebra 2

Consider the exam data below. Algebra score: 20 35 13 29 40 23 Calculus score: 41 69 34 72 86 58 Use your calculator to find the regression line for this data, and graph it on your scatterplot. b. Interpret the slope and intercepts of this line in the

89. ## math

the hawks won 7 games lost 6 games and tied 2 games what percent of all the games did they win.

90. ## Chemistry 120

* If 13.3 kilograms of Al2O3(s), 58.4 kilograms of NaOH(l), and 58.4 kilograms of HF(g) react completely, how many kilograms of cryolite will be produced? * Which reactants will be in excess? *What is the total mass of the excess reactants left over after

91. ## chemistry

a sample of sodium-24 with an activity of 12 mCi is used to study the rate of blood flow in the circulatory system. If sodium-24 has a half-life of 15 h, what is the activity of the sodium after 2.5 days. please show work.

92. ## Math

The management of a private investment club has a fund of \$114,000 earmarked for investment in stocks. To arrive at an acceptable overall level of risk, the stocks that management is considering have been classified into three categories: high-risk,

93. ## Chemistry

A base has a Kb of 2.5 x 10–11. Which of the following statements is true? This is a concentrated base. This base ionizes slightly in aqueous solution. This is a strong base. An aqueous solution of this base would be acidic.

94. ## Physics

King Kong carries Fay Wray up the 321 m tall Empire State Building. At the top of the skyscraper, Fay Wray’s shoe is knocked off with an initial upwards velocity of 5.1 and falls towards the ground. With what final velocity will the shoe be moving when

95. ## chemistry

write a net ionic equation for the following: 1)Iron (III) chloride reacts with Potassium hydroxide to produce Iron (III) oxide, Potassium chloride, and Hydrogen gas. 2)Hydrochloric acid reacts with Potassium carbonate to produce Potassium chloride,

96. ## chemistry

write a net ionic equation for the following: Copper (II) sulfate reacts with Ammonium hydroxide to produce Copper (II) oxide, Ammonium sulfate, and water.

97. ## Phsyics

A bullet of mass 1.8 X 10-3 kg is moving at +500. m/s when it impacts a tree stump. It penetrates into the stump 6.00 centimeters before coming to rest. 1. Assuming the acceleration to be constant, calculate the force (including direction) exerted by the

98. ## chemistry

How many liters of a 0.530M sucrose (C12H22O11) solution contain 1.3kg of sucrose?