# robert

Popular questions and responses by robert
1. ## 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

2. ## 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

3. ## 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

4. ## HELP !!! Algebra 2

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

5. ## 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

6. ## Physics - Electromagnetism 2

Two coils, held in fixed positions, have a mutual inductance of 165 µH. What is the peak emf in one coil when the current in the other coil is I(t) = 16.0 sin(1.15 103t), where I is in amperes and t is in seconds? Just a few hints on how to start it off

7. ## 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

8. ## 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

9. ## 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

10. ## Geometry

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

11. ## Algebra

Gabriel is making a mixture of compost and soil to use for a special plant. He wants his final mix to be 2 parts compost to 10 parts potting soil. He wants to end up with 12 kilograms of mix.

12. ## 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

13. ## 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.

14. ## 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

15. ## Geometry

Line TV bisects

16. ## Chemistry

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

17. ## 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

18. ## 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

19. ## Math

The function f given by f(x) = x^3 + 12x – 24 is? Increasing for all x's? Cause that's what I think..

20. ## 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

21. ## 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?

22. ## 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

23. ## english4

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

24. ## Chemistry

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

25. ## 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

26. ## 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?

27. ## 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.

28. ## 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?

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

30. ## 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?

31. ## 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

32. ## math

john ordered a new sign for her store. The sign has 4 sides . It also has 2 right angles. 1 acute angle , and 1 obtuse angle . What is the shape of the sign.

33. ## 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

34. ## Math

Go to Table 10-1 which is based on bonds paying 10 percent interest for 20 years. Assume interest rates in the market (yield to maturity) decline from 11 percent to 8 percent: A. What is the bond price at 11%? B. What is the bond price at 8%? C. What would

35. ## 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

36. ## 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

37. ## Physics - Electromagnetism

An inductor in the form of a solenoid contains 440 turns and is 15.8 cm in length. A uniform rate of decrease of current through the inductor of 0.421 A/s induces an emf of 175 µV. What is the radius of the solenoid?

38. ## math

Simplify the expression (x to the fourth power times x cubed)squared/x to the 4. a)x b)x to the fifth c)x to the tenth d)x to the 20 I kind of confused. I tried to divide by 4, but i couldn't get anything. I need help?

39. ## Chemistry

A sample of metallic element X, weighing 4.315g, combines with0.4810 L of Cl2 gas (at normal pressure and 20.0C) to form the metal chloride with the formula XCl. If the density of Cl2 gas under these conditions is 2.948g/L, what is the mass of chlorine?

40. ## Microeconomics

4a. In the market for hand-made guitars, when the price of guitars is \$800, annual revenues are \$640,000. When the price falls to \$700, annual revenues decline to \$630,000. Over this range of guitar prices, is the demand for hand-made guitars elastic,

41. ## english 4

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

42. ## 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*

43. ## math

North Pole Cruise Lines issued preferred stock many years ago. It carries a fixed dividend of \$6 per share. With the passage of time, yields have soared from the original 6 percent to 14 percent (yield is the same as required rate of return). A. What was

44. ## math

write 362.63 in words

45. ## science

the ? describes the steps you use during an experiment?

46. ## 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

47. ## 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?

48. ## 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)

49. ## 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

50. ## 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?

51. ## English

What are the nouns and verbs in the sentence. Life is full of choices, so I must learn to make good ones.

52. ## Biochemistry

Acetylcholinesterase catalyzes the hydrolysis of the neurotransmitter acetylcholine: Acetylcholine + H2O  actetate + choline The KM of acetylcholinesterase for its substrate acetylcholine is 9 x 10-5 M. In a reaction mixture containing 5 nanomoles/ml of

53. ## precalculus

Simplify the Factorial Expression. (3n+1)!*3!/(3n-2)!

54. ## Psychology

compare and contrast the strengths and weaknesses of two different approaches to study the following issue: You have developed a new drug that you believe is effective in reducing appetite. As a result of some preliminary research, you have been given a

55. ## Physics- Charge in electromagnetic field

An antiproton (which has the same properties as a proton except that its charge is -e) is moving in the combined electric and magnetic fields of the figure: h tt p://post image. org/image/2sh3s3hs4/ What are the magnitude and direction of the antiproton's

56. ## 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

57. ## Chemistry 101

Which of the following will not increase the rate of a reaction? a. using a catalyst b.increasing the temperature c. decreasing the concentration of a reactant d. finding a shorter path for the reaction to take place e. increasing the kinetic energy

58. ## math

Solve each equation and leave the answer in simplest radical form. x squared+6x-9=0 n squared-2n+2=5 3y squared-4y-2=0 I never learned how to do this. Can you help me?

59. ## Physics

Calculate the percentage increase in length of a wire of diameter 2.2 mm stretched by a load of 100 kg.Young's modulus of wire is 12.5 × 10^10 N/m^2

60. ## 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

61. ## physics

During an Apollo lunar landing mission, the command module continued to orbit the Moon at an altitude of about 58.6 km. How long did it take to go around the Moon once, in seconds?

62. ## pre calc

The number N of bacteria in a culture at time t (in hours) grows exponentially according to the function N(t) = 1000e^0.01t When will the number of bacteria reach 1700? I though you would do 1700=1,000^e0.01t and solve for t but i keep getting the wrong

63. ## 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

64. ## Math

An 8.5 centimeter green bean pod contains peas that average 0.45 centimeter in diameter. How many peas are in the pod

65. ## Calculus

Two points P and Q are connected by a straight road of length d. At time t = 0, a car starts driving from P to Q at a constant speed c. At t = 0, a bee starts flying from Q toward the car at a constant speed b > c, and takes a zig-zagging path, reversing

66. ## algerbra

Consider the following system of equations. y = 4x - 4 y - 4x = 3 What can you conclude about the system of equations?

67. ## Chemistry

1.) A 3.000gram sample of a hydrate compound containing Co, C2O4, and H2O was combusted to give 1.316g of Co3O4. What is the percentage of Cobalt in the oxide? 3.) 2.000 grams of a sample containing Co, C2O4, and H2O showed there to be 0.9621g of oxalate

68. ## Chemistry

An aqueous solution of ethanol is 14.1M C2H5OH. The density of the solution is 0.853g/mL. What is molality of ethanol in the solution? What is mass % of ethanol in solution? I got the molality which is -21.7 ethanol, but I can't figure out how to get the

69. ## chemistry

if a reaction vessel contains 11.5g NH3, 12.0g O2, and 10.5g CH4, what is the maximum mass in grams of hydrogen cyanide that could be made?

70. ## chemistry

copper metal reacts with nitric acid. assume that the reaction is 3Cu(s) + 8HNO3(aq) ——> 3Cu(NO3)2(aq) + 2NO(g) + 4H2O(l). if 5.58 grams of Cu(NO3)2 is obtained, how many grams of nitrogen monoxide would have formed

71. ## english4

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

72. ## World geography

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

73. ## Chemistry

Ethanol, C2H5OH or C2H6O, is mixed with gasoline and sold as gasohol. Given the following thermo-chemical reaction, calculate the kilograms (kg) of CO2 produced when enough ethanol is combusted to provide (or give off) 369 kJ of heat: C2H5OH (l) + 3 O2 (g)

74. ## SQL

1- A SQL statement is needed to create a stored procedure that has one input parameter of data type int. The stored proc selects the supplierId field and the total, or sum, of all Count field values for each group of supplierId fields from the Part table.

75. ## 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

76. ## chemistry

how many grams of manganese (4) oxide are needed to make 5.6 liters of a 2.1 solution

77. ## 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

78. ## 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

79. ## math

How do you find the area of something?

80. ## Chemistry

True or false? All enzymes are specific to a single substrate chemical. That is, an enzyme will catalyze reactions of one molecule only.

81. ## Chemistry

Calculate the enthalpy change when 100. g of ice at 0.0 °C is heated to liquid water at 50.0°C. (The heat of fusion for water is 333 J/g.) 1)54.2 kJ 2)33.3 kJ 3)54,220 kJ 4)20.9 kJ

82. ## Econ Help

Please help! Trying to study for exam! An article in the New York Times (Oct. 18, 1990) described a successful marketing campaign by the French champagne industry. The article also noted that “many executives felt giddy about the stratospheric champagne

83. ## Calc Help

A manufacturer's revuenve in dollars is given by R(x)=1500x-0.02x^2 where x is number of units sold. Find the marginal revenue function. Use the derivative to estimate the revenue gained from selling the 35th unit. The marginal revenue function is the

84. ## Pre Calculas

Complete the identity sin theta / cos theta + cos theta / sin theta = ? Do you mean (sin theta/cos theta) + (cos theta/sin theta) ? That would equal tan x + cot x = tan x + (1/tan x) = (tan^2 x + 1)/ tan x I don't see any way to further simplify it.

85. ## Math

Use the matrix method to solve 5x+3y=35 3x-4y=-8

86. ## 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

87. ## Organic Chemistry

Procedure: 1) Accurately weigh approximately 0.40 g of Dimethyl maleate into a 50 mL round bottom flask that possesses a ground glass joint, and record the weight. 2) Dissolve the Dimethyl maleate in 10 mL of methanol, and add approximately 5 drops of

88. ## Organic Chemistry

Procedure: 1) Accurately weigh approximately 0.40 g of Dimethyl maleate into a 50 mL round bottom flask that possesses a ground glass joint, and record the weight. 2) Dissolve the Dimethyl maleate in 10 mL of methanol, and add approximately 5 drops of 10%

89. ## Math

Find the vertex focus directrix and axis of symmetry of each parabola y²–8x–6y–3=0

90. ## 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

91. ## math

i need ratios of 5/6

Please could you help me with a good attention getter for a presentation on how interviews were done

93. ## Math

Gina has 4 red ribbons, 6 times as many blue ribbons as green ribbons, and 1/4 as many green ribbons as red ribbons. How many ribbons does she have in all?

94. ## physics

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

95. ## Grammar

When ending a letter to a high gov't official with the phrase 'Respectfully Submitted', are both words capitalized, or just the first?

96. ## Physics

While John is traveling along a straight interstate highway, he notices that the mile marker reads 280. John travels until he reaches the 156-mile marker and then retraces his path to the 175-mile marker. What is John's resultant displacement from the

97. ## 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?

98. ## physics

car doing 60 mph and skids for 52.3 meters what is the speed at end of skid co/friction is 0.693 urgent help please