# robert

Most popular questions and responses by robert
1. ## HELP !!! Algebra 2

15. What is the solution of the linear-quadratic system of equations? {y = x^2 + 5x - 3} {y - x = 2}

2. ## Algebra 2 help :)

Any number in the form of a+-bi , where a and b are real numbers and b not equal 0 is considered a pure imaginary number. TRUE OR FALSE The minimum value is the smallest y-value of a function. T RUE OR FALSE i2 = square root of -1. TRUE OR FALSE Complex

3. ## Social studies

I need help with lesson 12 unit 2 for seventh grade there is a unit test called Eastern Europe and Russia and unit test 7. Many words offer clues to media bias. Which word below would mostly likely signal bias. A. Was B. Did C. Should D. Might

4. ## English 11

1. Olaudah Equiano wrote (1 point) a book of letters to his African family. a history of the West Indian slave trade. stories of early slavery in Virginia. the first autobiography by a black man in America. 2. The term “the Middle Passage” refers to (1

5. ## Physics

A 40.0kg child is in a swing that is attached to ropes 2.00m long. Find the gravitational potential energy associated with the child relative to the child's lowest position under the following conditions: a) When the ropes are horizontal b) When the ropes

6. ## chemistry

Iron(II) can be oxidized by an acidic K2Cr2O7 solution according to the net ionic equation. Cr2O72− + 6 Fe2+ + 14 H+ 2 Cr3+ + 6 Fe3+ + 7 H2O If it takes 44.0 mL of 0.0250 M K2Cr2O7 to titrate 25.0 mL of a solution containing Fe2+, what is the molar

7. ## language arts

Which of these best states Nonno Frankie’s main idea of how to win a fight?

8. ## Chemistry

An element has three stable isotopes. One has a mass number of 63 and an abundance of 50%. The second has a mass number of 65 and an abundance of 30%. The third has a mass number of 67 and an abundance of 20%. Calculate the relative atomic mass of this

9. ## english

3. In “The Pigman & Me,” the author creates a mood of suspense by focusing most of the action around a fight between two boys at school. a tree cut almost to its heart. Nonno Frankie’s advice to Paul. concerns about how a girl will react.

10. ## physics

If 3000ft/3 of air crossing an evaporator coil and is cooled from 75F to 55F, what would be the volume of air,in ft/3, exiting the evaporator coil?

Please help. I have no idea how to do these 4 homework problems. 1- How many milliliters of 0.140 M HCl are needed to completely neutralize 42.0mL of 0.106 M Ba(OH)2 solution? 2-How many milliliters of 0.123 M H2SO4 are needed to neutralize 0.250 g of NaOH

12. ## Chemistry

Octane (C8H18) undergoes combustion according to the following thermochemical equation: 2 C8H18(l) + 25 O2(g) ---> 16 CO2(g) + 18 H2O(l) DHo = -11,200 kJ Given : DHfo [CO2(g)] = -393.5 kJ/mol and DHfo[H2O(l)] = -285.8 kJ/mol. Calculate the enthalpy of

13. ## Physics concept question

A long straight horizontal wire carries a current I = 2.10 A to the left. A positive 1.00 C charge moves to the right at a distance 4.50 m above the wire at constant speed v = 2250 m/s. What are the magnitude and the direction of the magnetic force on the

14. ## Chemistry

Is ClO2>- a Bronsted acid, base, or both?

15. ## Chemistry (Biochem)

I'm given two pictures looking down the alpha helices of a coiled coil dimer of alpha-keratin. I'm asked to identify three statements out of the following that are true. My guesses are 2, 3, and 6. 1. Leu-Glu-His-Val-Cys-Lys-Ser is a likely repeat in the

16. ## English

1) The following passage is an example of which literary element? "Give back your heart to itself, to the stranger who has loved you all your life, whom you ignored for another, who knows you by heart." a)paradox b)magical realism c)metaphor d)hyperbole*

17. ## Physics - Electromagnetism

This is the last question for a final exam preparation sheet and I can't figure out the answer. Any help would be greatly appreciated. Thank you. - One very long wire carries current 10.0 A to the left along the x axis. A second very long wire carries

18. ## Geometry

Question: If a ray divides an angle into two supplementary angles, then the original angle is a straight angle. True?

19. ## Chem

Depending upon the tip of a dropper pipet, there are approximately 20 drops per milliliter of water. The experimental procedure indicates the addition of 5-10 drops of each solution to the test tubes. Calculate the volume range in milliliters for the

20. ## math

If A + B + c = 180 then show that sinA + sinB + sinC=4cosA/2. cosB/2 . cosC/2

21. ## Physics

A cube made ouk and side 15cm floats in water with 10.5cm of it's depth below the surfaces and with it's side's vertical what is density of oak

22. ## physics

A bus accelerates from rest at 1.5m/s^2 for 12s. It then travels for 25s after which it slows to a stop with an acceleration of magnitude 1.5m/s^2. (a) Find the total distance the bus travels And its average velocity of the trip.

23. ## Physics - Electromagnetism

A square loop (length along one side = 20 cm) rotates in a constant magnetic field which has a magnitude of 2.0 T. At an instant when the angle between the field and the normal to the plane of the loop is equal to 20 and increasing at the rate of

24. ## Chemistry

59.0 mL of a 1.80 M solution is diluted to a total volume of 268 mL. A 134-mL portion of that solution is diluted by adding 171 mL of water. What is the final concentration? Assume the volumes are additive.

25. ## math

Average Growth Rate(2000-2009)of China - GDP: 10.9 Population: 0.8 Per Capita GDP: 10.1 Ethiopia - GDP: 7.5 Population: 2.8 Per Capita GDP: 4.7 How fast does total output(GDP)have to grow in order to raise per capita GDP in Instructions: Enter your

26. ## Physics

A 1125 kg car carrying four 80 kg people travels over a rough "washboard" dirt road with corrugations 4.0 m apart which causes the car to bounce on its spring suspension. The car bounces with maximum amplitude when its speed is 17 km/h. The car now stops,

27. ## Chemistry 2

Supposed you stoppered the flasks after your titration to determine the equilibrium constant and kept the solutions for another day so that the equilibrium was re-established. What would happen to the amount of ethanol present? What would be the

28. ## english 4

The two waiters exchanged a look whose meaning was clear to me. what type of clause or phase is used?

29. ## physics

A cubical piece of heat-shield-tile from the space shuttle measures 0.18 m on a side and has a thermal conductivity of 0.065 J/(s·m·C°). The outer surface of the tile is heated to a temperature of 1050°C, while the inner surface is maintained at a

21. A candle is 17 in. tall after burning for 3 hours. After 5 hours, it is 15 in. tall. Write a linear equation to model the relationship between height h of the candle and time t. Predict how tall the candle will be after burning 8 hours. (2 points)

31. ## Physics - Verification

Two long straight parallel wires separated by a distance of 20 cm carry currents of 30 A and 40 A in opposite directions. What is the magnitude of the resulting magnetic field at a point that is 15 cm from the wire carrying the 30-A current and 25 cm from

32. ## physics

200g of steam at 110°C is condensed, and the resulting water is frozen into ice at 0°C. How much heat was removed?

33. ## chemistry

in an experiment, 2.50g of salicylic acid is reacted with 10.31g of methanol. the yield of methyl salicylate, C8H8O3, is 1.27g. what is the percentage yield?

34. ## Matg

Juanita told her dad that she won 80% of the card games she played yesterday. If she won 4 games, how many games did she play?

35. ## Statistics

Q1:(a) Make a relative frequency table of the data. Enter your answers to three decimal places. Cell Phone Owned Relative Frequency Android smartphone iPhone smartphone Blackberry smartphone Cell phone not smartphone No cell phone Total (b) Round your

36. ## math

Susie designed an excersise program for herself. One part of the program requires her to walk between 25 to 30 miles each week. She plans to walk the same distance each day five days a week. What is the range of miles that she should walk each day? Write

37. ## Physics

A block cedar has a mass of 200 kg and density of 570 what fraction of the wood will be surface of block is floating in water

38. ## Physics AP

A conical pendulum is formed by attaching a 50 g mass to a 1.2m string. The mass swings around a circle of radius 25cm. A claculate the speed of the mass. B Calculate the acceleration of the mass. C calculate the tension in the string

39. ## General Chemistry 132

When solid NH4NO3 is dissolved in water at 25celcius, the temp of the solution decreases. What is true about the signs of enthalpy and entropy for this process? I understand entropy is positive, however, i do no understand why enthalpy is also positive.

40. ## Geometry

Line TV bisects

41. ## english4

He will not allow the table to be moved. identify the Verbal in the sentence and type of verbal

42. ## History

How does Galileo defend himself against these charges of heresy by the Inquisition?

43. ## Physical Science

If a skydiver has a forward velocity of 40 m/s, what is the forward velocity after one second? What is the downward velocity after one second?

44. ## english4

what type of clause or phrase is used in the sentence: we hit a snag while rowing to shore

45. ## math

The bases of trapezoid ABCD are \overline{AB} and \overline{CD}. Let P be the intersection of diagonals \overline{AC} and \overline{BD}. If the areas of triangles ABP and CDP are 8 and 18, respectively, then find the area of trapezoid ABCD.

46. ## math help

Pat recorded the weights of the first ten fish she caught and released at Mirror Lake this season. The weights were 8 lb, 6 lb, 9 lb, 6 lb, 7 lb, 5 lb, 7 lb, 6 lb, 23 lb, and 6 lb. What is the median of the data set

47. ## median help

Pat recorded the weights of the first ten fish she caught and released at Mirror Lake this season. The weights were 8 lb, 6 lb, 9 lb, 6 lb, 7 lb, 5 lb, 7 lb, 6 lb, 23 lb, and 6 lb. What is the median of the data set

48. ## math

describe a real world relationship between the area of a rectangle and its width, as the width varies and the length stays the same. Sketch a graph to show this relationship.

49. ## chemistry

Ibuprofen, the active ingredient in Advil, is made up of carbon, hydrogen, and oxygen atoms. When a sample of ibuprofen, weighing 5.000 g, burns in oxygen, 13.86g of CO2 and 3.926 g of water are obtained. What is the simplest formula of ibuprofen? I need

50. ## calculus

a fence 8 ft tall stands on level ground and runs parallel to a tall building. if the fence is 1 ft from the building, find the length of the shortest ladder that will extend from the ground over the fence to the wall of the building. (hint #1: if L

51. ## statistics

The results of a medical test show that of 66 people selected at random who were given the test, 3 tested positive and 63 tested negative. Determine the odds in favor of a person selected at random testing positive on the test.

52. ## math

A transversal intersects two parallel lines and forms eight angles. Which of the following statements is false? a)alternative interior angles are always congruent. b)corresponding angles are always congruent. c)adjacent interior angles are always

53. ## chemistry

how many milliliters of 0.250 M KMnO4 are needed to react with 3.55 grams of iron(II)sulfate, FeSO4? the reaction is as follows: 10FeSO4(aq)+2KMnO4(aq)+8H2SO4(aq)¨ 5Fe2(SO4)3(aq)+2MnSO4(aq)+K2SO4(aq)+8H2O(l)

54. ## Physics

In Case A the mass of each block is 4.8 kg. In Case B the mass of block 1 (the block behind) is 9.6 kg, and the mass of block 2 is 4.8 kg. No frictional force acts on block 1 in either Case A or Case B. However, a kinetic frictional force of 9.4 N does act

55. ## Chemistry

Dividing 0.32g of sulfur by its density of 2.07g/cm^3 results in an answer with three significant figures? Am I right?

56. ## Math

3. A processor makes two components, A and B, which are then packaged together as the final product (each product sold contains one A and one B). The processor can do only one component at a time: either it can make As or it can make Bs. There is a setup

57. ## Math

Find any intervals where the function f(x)=−(5x+5sin(x)),0≤x≤2π is increasing/decreasing.

58. ## World geography

This very southern city in Africa is in an area of moderate rainfall

59. ## Physics

Huck Finn walks at a speed of 0.60 m/s across his raft (that is, he walks perpendicular to the raft’s motion relative to the shore). The raft is traveling down the Mississippi River at a speed of 2.20 m/s relative to the river bank. What is Huck’s

60. ## Algebra 2 Helpp :(

QUESTIONS (vvv) (1) Solve the system by subsitution 2x + y = -11 3 - 4y = 11 (2) Solve the system by elimination 2x + 6 = -12 5x - 5y = 10 (3) What is the solution of the following system? -3x - 2y = -12 9x + 6y = -9 (4) What is the solution of the

61. ## Math

A helicopter drops a box of supplies after a disaster. The function represents the height y (in feet) of the box t seconds after it is dropped. After how many seconds does the box hit the ground? y=100-16t^2

62. ## Math (Geometry)

"The graph shows types of trash in a typical American city. Find the measure of each central angle to the nearest whole number." (I do not want all the answers, I just want to know HOW to get them so I will only post the first three problems that

63. ## Physics

Bert is standing on a ladder picking apples in his father's orchard. As he pulls each apple off the tree, he tosses it into a basket that sits on the ground 2.2 m below at a horizontal distance of 1.3 m from Bert. How fast must Bert throw the apples

64. ## Microeconomics - University of Boston

4. If Cassandra bought 16 cotton blouses last year when her income was $40,000 and she buys 24 cotton blouses this year when her income is$50,000, then what is her income elasticity of demand? Interpret what the income elasticity of demand you just

65. ## physics hw

A 300. kg roller coaster car is traveling at a constant speed of 15 m/s over a hill with a radius of curvature of 30. m. b. What is the normal force acting on the car at the top of the hill? c. Assume that the car is at the intersection of the radius and

66. ## statistics

Smith is a weld inspector at a shipyard. He knows from keeping track of good and substandard welds that for the afternoon shift 5% of all welds done will be substandard. If Smith checks 300 of the 7500 welds completed that shift, what is the probability

67. ## Physics

A meter stick balances horizontally on a knife-edge at the 50.0 cm mark. With two 5.00 g coins stacked over the 7.0 cm mark, the stick is found to balance at the 41.0 cm mark. What is the mass of the meter stick? The answer is 38g but I don't understand

68. ## College Algebra

If a ball dropped from the top of a 400 ft building to hit the ground, how long would it take in seconds?

69. ## Algebra 1

The amount of money in an account may increase due to rising stock prices and decrease due to falling stock prices. Nathan is studying the change in the amount of money in two accounts, A and B, over time. The amount f(x), in dollars, in account A after x

70. ## Chemistry

I had an equilibrium laboratory and had to answer a few questions after the lab. Here are 2 questions I can't seem to know how to answer. 1. Explain in your own words why a saturated solution in contact with some undissolved solid is considered to be an

71. ## Physics

a 2 kg block slides down a frictionless incline from point A to point B. A force(magnitude P=3N) acts on the block between A and B, as shown. Points A and B are 2 m apart. If the kinetic energy of the block at A is 10 J, and the work done by gravity is

72. ## calculus

The illumination of an object by a light source is directly proportional to the strength of the source and inversely proportional to the square of the distance from the source. If two light sources, one three times as strong as the other, are placed 11 ft

73. ## I guess this is physics related?

What is the biggest source of error in measuring the acceleration of a ball down a ramp? knowing the length of the ramp accurately measuring the time knowing the height of the ramp knowing the mass of the ball****

74. ## Physics

A speedboat starts from rest and accelerates at +1.98 m/s2 for 8.25 s. At the end of this time, the boat continues for an additional 5.58 s with an acceleration of +0.348 m/s2. Following this, the boat accelerates at -1.42 m/s2 for 7.22 s. (a) What is the

75. ## life orientation project

research and briefy discuss the following processes that the community must engage whenever there is an issue before and during a protest :how to engage in a protest, protest restrictions,permit to hold a protest, activities during a protest,as well as the

76. ## Physics - Current Loop

A current loop in a motor has an area of 0.85 cm^2. It carries a 240 mA current in a uniform field of 0.62 T. What is the magnitude of the maximum torque on the current loop?

77. ## math

2 line segments intersect to form an angle that has a measure pf 50.7 degrees. What is the measure in degrees of an angle that is supplementary to this angle. I don't understand what this question is asking me. Can someone explain it to me?

78. ## Math

The formula h=48t-16t^2 gives the height, h, in feet, of an object projected into the air after t seconds. If an object is propelled upward, at what time(s) will it reach a height of 32 feet above the ground?

79. ## Chemistry

Hello, I had a lab about calorimetry and one of the questions was if the reaction of acetone with hypochlorite is an oxidation/reduction or acid/base. Would the answer be: oxidation/reduction because the oxygen from the hydroxide from the Sodium hydroxide

80. ## Algebra 2

3. Identify the vertex and the axis of symmetry of the graph of the function y = 3(x + 2)2 – 3. (1 point) A- vertex: (2, –3); axis of symmetry: x = 2 B- vertex: (–2, –3); axis of symmetry: x = –2 C- vertex: (2, 3); axis of symmetry: x = 2 D-

81. ## Chemistry

Derive a formula for the molar mass of the solute in terms of the freezing point depression, deltaT, the freezing-point constant, Kf, and the masses of solvent, msolvent, and solute, msolute, used in an experiment like this one. SHow your work and include

82. ## Linear Algebra

The Vector v has a length of 15 and points at an angle of 30 degrees. The Vector u has a length of 17 and points at an angle of 55 degrees. What is u*v? I know to get my answer I need to use this format |u|*|v|*cos(theta) however I am stuck at setting up

83. ## physics

What is the mass which causes a spring of k = 100 N/m to stretch by 10 cm?

84. ## College algebra

Matt and Jena, working together, can clean the house in 9 hours. Working alone, Jena takes three times as long as Matt. How long does it take Matt to clean the house.

85. ## Algebra 2

Can you double check my answer The lengths of the sides of a rectangular window have the ratio 1.6 to 1. The area of the window is 2,560 square inches. What are the dimensions of the window? (1 point) 50.6 inches by 50.6 inches 40 inches by 64 inches 40

86. ## Inorganic Chem

If you forget to add phenolphthalein solution to a vinegar solution(after adding NaOH solution), how might you salvage the titration?

87. ## Chemistry

Calculate the solubility (in g/L) of calcium fluoride in water at 25°C if the Ksp for is 1.5 × 10-10 .

88. ## Math

Given that the graph of f passes through the point (1, -4) and that the slope of its tangent line at (x,f(x)) is 2x+1, find f(-1) (graph is hypothetical).

89. ## math

Marla begins walking at 3 mi/h toward the library. Her friend meets her at the halfway point and drives her the rest of the way to the library. The distance to the library is 4 miles. How many hours did Marla walk? First, I set up an equation, 3(h+.5)=4h.

90. ## Accounting

Jack Hammer invests in a stock that will pay dividends of $2.00 at the end of the first year;$2.20 at the end of the second year; and \$2.40 at the end of the third year. Also, he believes that at the end of the third year he will be able to sell the stock

91. ## science

the ? describes the steps you use during an experiment?

92. ## Physics

A roulette wheel with a 1.0m radius reaches a maximum angular speed of 18 rad/s before it stops 35 revolutions ( 220 rad ) after attaining the maximum speed. How long did it take the wheel to stop? Unless you mean the 35 revs occur after max speed, it

93. ## CHemistry- For Dr.Bob

Hey Dr.Bob, I asked two days ago a question about a titration lab I had that you answered, but I still have one more question about that lab. Here's the lab summary: For my chemistry of solutions class, we had a titration lab where we titrated NaOH into an

94. ## Physics

Three uniform meter sticks, each of mass M, are placed on the floor as follows: stick 1 lies along the y axis from y = 1.3 to y = 2.3 m, stick 2 lies along the x axis from x = 0.0 to x = 1 m, stick 3 lies along the x axis from x = 1.0 m to x = 2.0 m. Find

95. ## Statistics

. A 2003 Harris Poll of 993 randomly selected American adults found that 69% believed in capital punishment (death penalty). A sample size of 1010 American adults in 2000 found that 64% believed in capital punishment. Write the hypotheses for a

96. ## Math

An article in the local paper states that 30% of the students at Oak Grove Middle School earned a place on the Silver Honor Roll. If there are 920 students at Oak Grove, how many are on the Silver Honor Roll? USE A PERCENT RULER TO HELP YOU DECIDE. SHOW

97. ## chemistry

A saturated solution of ammonium sulfate, (NH4)2SO4, in water at 30 0C contains 78.0 g (NH4)2SO4 per 100.0 g H2O. What is the molality of this solution?

98. ## pre calc

The population of a colony of mosquitoes grows exponentially according to the function P(t) = P0ekt 1. If there are 1,000 mosquitoes initially and there are 1800 after 1 day, what is the size of the colony after 3 days? 2. How long will it take the colony