# .

Popular questions and responses by .
1. ## Calculus

Find the rate of change of f(x,y,z) = xyz in the direction normal to the surface yx^2 + xy^2 + yz^2 = 75 at (1,5,3). I keep getting this wrong and I don't know what I did right. The answer's 147/sqrt(101) but I got 357/sqrt(1361). Is my method right? Or

2. ## Chemistry

Which temperature change would cause the volume of a sample of an ideal gas to double when the pressure of the sample remains the same? 1. from 200°C to 400°C 2. from 400°C to 200°C 3. from 200K to 400K 4. from 400K to 200K

3. ## Chemistry

A quantity of N2 occupies a volume of 1 L at 290 K and 1.5 atm. The gas expands to a volume of 2.7 L as the result of a change in both temperature and pressure. Find the density of the gas at these new conditions (in grams per liter).

4. ## Chemistry

1. For which process is dS system negative? A)evaporation of 1 mol of CCl4(l) B)compressing 1 mol of Ne at constant temperature from 0.5 atm to 1.5 atm C)mixing 5 mL of ethanol with 25 mL of water D)raising the temperature of 100 g of Cu from 275 K to 295

5. ## Calculus

For each sequence an find a number k such that nkan has a finite non-zero limit. (This is of use, because by the limit comparison test the series ∑n=1∞an and ∑n=1∞n−k both converge or both diverge.) D. a_n = ( (7n^2+7n+7)/(5n^8+3n+5√n) )^7

6. ## algebra

Lesson 10: Exponents and Exponential Functions Unit Test

7. ## math

how much should be invested now at an interest rate of 6.5% per year, compounded continuously, to have \$3000 in 4 years? do not round any intermediate computations and round answer to nearest cent.

8. ## Chemistry

A dry mixture of kno3 and sand could be separated by 1. adding water to the mixture and filtering 2. adding water to the mixture and evaporating 3. heating the mixture to a high temperature 4. cooling the mixture to a low temperature

9. ## History

1. Arrange the events in correct chronological order. Place the earliest event at the top and the latest event at the bottom. Israel withdraws from Gaza. Israel and the PLO sign the Oslo Accords. Israel takes control of West Bank and Gaza. Hamas takes

10. ## chem

Q: Calculate ℰ° values for the following cells. Which reactions are spontaneous as written (under standard conditions)? Balance the equations. Standard reduction potentials are found in the Standard Reduction Potentials table. (Use the lowest possible

11. ## Art

Louis Daguerre's contribution to photography changed which of the following.

12. ## Calculus

A car drives down a road in such a way that its velocity (in m/s) at time t (seconds) is v(t)=2t^(1/2)+3. Find the car's average velocity (in m/s) between t=5 and t=8. ---- So I used integrals for this and put ∫2t^(1/2)+3 and got 4/3(t^(3/2))+3t. Then I

13. ## Economics

How does scarcity affect producers? A.) Limited costs prevent producers from hiking prices. * B.) Limited demand prevents producers from offering low prices. C.) Limited time prevents producers from finding the best employees. D.) Limited resources prevent

14. ## Physics

My answer was 19.8 cm but it was incorrect. A basket of negligible weight hangs from a vertical spring scale of force constant 1500 N/m. If you suddenly put a 3.00 kg adobe brick in the basket, find the maximum distance that the spring will stretch.

15. ## Trigonometry

How do I solve these? 1) 2sinxcosx-cosx=0 2) cos^2(x)-0.5cosx=0 3) 6sin^2(x)-5sinx+1=0 4) tan^2(x)+tanx-12=0

16. ## math

a line passes through the point (-4,6) and has a slope of -5/4. Write an equation in point-slope form for this line.

17. ## Science

When entering science lab, which of the following should be done by science students? Students should start working on their experiment. Students must talk to their lab partner to see what they need to do next. Students must wait for their teacher to give

18. ## Chemistry

A particular metallic element, M, has a heat capacity of 0.36 J*g*K, and it forms an oxide that contains 2.90 grams of M per gram of oxygen. (a) Using the law of Dulong and Petit (Cp x M = 25 J*mol*K), estimate the molar mass of the metal M [Answer: _____

19. ## Career

i just need some help making sure my answers are correct:) 1. And art director is an example of: a. a blue-collar job. b. a white-collar job. (my answer) c. a production job. d. a market research job. 2. Some merchandisers design window displays. a. True

20. ## Chemistry

Predict the mode of decay for Mn-59. a. beta decay

21. ## Calculus

Q: Find the antiderivative F of f(x)=4−3(1+x^2)^−1 that satisfies F(1)=−9. I got 4x-3arctan(x), but it still seems to be incorrect, and the hw doesn't care for constants (like +C at the end). Am I missing something?

22. ## Health

3. Fruits and vegetables are good sources of (Select all that apply.) (2 points) A) carbohydrates. B) fats. C) proteins. D) fiber

23. ## math

The credit remaining on a phone card (in dollars) is a linear function of the total calling time made with the card (in minutes). The remaining credit after 26 minutes of calls is \$16.36 , and the remaining credit after 45 minutes of calls is \$13.70 . What

24. ## chemistry 30

Calculate the enthalpy of reaction for the combustion of ethene.

25. ## MATH

A basket contains the following pieces of fruit: 3 apples, 2 oranges, 2 bananas, 2 pears, and 5 peaches. Jonas picks a fruit at random and does not replace it. Then Beth picks a fruit at random. What is the probability that Jonas gets a peach and Beth gets

26. ## Physics

Some sliding rocks approach the base of a hill with a speed of 11.0 m/s. The hill rises at 44.0 degrees above the horizontal and has coefficients of kinetic and static friction of 0.410 and 0.630, respectively, with these rocks. 1) Find the acceleration of

27. ## Physics

An air-conditioner unit is fastened to a roof that slopes upward at an angle of 37.0 degrees. In order that the unit not slide down the roof, the component of the unit's weight parallel to the roof cannot exceed 560 N. What is the maximum allowed weight of

28. ## Trigonometry

Verify the identity. sin2x/cosx + sinx = 2sinx Solve for all values of x: 6cos2x-7cosx-3=0 If f(x)=cos1/2x-sin2x find the value of f(pi)

29. ## Chemistry

A sealed flask containing 1.0 mole of H (g) and a sealed flask containing 2.0 moles of He(g) are at the same. 2 temperature. The two gases must have equal 1. masses 2. volumes 3. average kinetic energies 4. numbers of molecules

30. ## physics

a 60 kg boy and a 40 kg girl at rest push off one another on some roller skates. if the speed of the guy is 5 m/s what is the speed of the female?

Architects design roads True (my answer) False Archivists care for art museum paintings and sculptures True (my answer) False

32. ## Career

just need help checking my answers:) 1. customer service is the same as professional sales a.True b. False (my answer) 2. corporate computer support departments have computer repair personnel who are part of: a. production b.marketing c.maintenance (my

33. ## Math

Also does p v q = p? And p v q = q?

34. ## Math

Is p ^ q logically equivalent to q ^ p?

35. ## History

what do we gain from being able to "step back" from our own way of life as Miner has done here?

36. ## Chemistry

The normal boiling point for acetone is 56.5°C. At an elevation of 6500 ft, the atmospheric pressure is 606 torr. What would be the boiling point of acetone (ΔHvap = 32.0 kJ/mol) at this elevation? What would be the vapor pressure of acetone at 25.0°C

37. ## Chemistry

Q: The value of ΔS° for this reaction is 177 J/K. At what temperatures is this reaction spontaneous at standard conditions? Assume that ΔH° and ΔS° do not depend on temperature. I got 300.768 K through dG = dH-TdS and T=dH/dS but it's still

38. ## s.s

how did William Travis actions contribute to the beginning of the Texas Revolution? a.travis led attacks on San Antonio to instigate Mexican troops to start a war. *** b.travis led attacks on Mexican officials at Anahuac to get Texas to rebel against

39. ## Science!!!

1. Why can certain stars sometimes be identified as eclipsing binary stars? A. They are brighter than any single star B. They are all white dwarfs C. They become dimmer at regular intervals D. They are cool red stars

40. ## Science

Which of the following illustrates how fossil fuels can be conserved? A.) driving more frequently B.) developing more coal-burning power plants. * C.) reducing electrical use Can someone check this please?

41. ## math

suppose that \$3500 is borrowed for three years at an interest rate of 4% per year. compounded continuously. find the amount owed, assuming no payments are made till the end. Round to the nearest cent.

42. ## algebra 2

Reuben deposited \$2000 into an account with a 3.8% annual interest rate, compounded semiannually. Assuming that no withdrawals are made, how long will it take for the investment to grow to \$3000?

43. ## math

The function g is defined by g(x)=2x^2-4 Find g(5x).

44. ## math/science

The total surface area of Earth is about 1.97 × 10^8 square miles. The surface area of land on Earth is about 5.73 × 10^7 square miles. Find the ratio of surface area of land to that of the entire planet.

45. ## PHYSICS

5 kg cart is at the bottom of a 10 m hill. For the cart to reach the top of the hill, what is the minimum kinetic energy of the cart?

46. ## math

Find the volume of a square pyramid with a base length of 9 cm and a height of 4 cm. 324 cm3 108 cm3 36 cm3 152 cm3 miss sue do you think it could be c

47. ## High School Physics

The player kicks a football with an initial speed of v0 = 98 ft/s. Determine the two possible values for the angle of the kick, theta. The distance of the football field is 126 ft. Also determine the corresponding time at each of these two angles.

48. ## Physics

Two students are on a balcony 22.3 m above the street. One student throws a ball, b1, vertically downward at 19.2 m/s. At the same instant, the other student throws a ball, b2, vertically upward at the same speed. The second ball just misses the balcony on

49. ## Physics

Can anyone answer part 3 for me? I've tried so many incorrect answers that I've already given up: 1.00, 1.50, 2.00, 3.00, 9.40 Question: A slingshot obeying Hooke's law is used to launch pebbles vertically into the air. You observe that if you pull a

50. ## Physics

A current of a river flows steadily from west to east at 1.00 m/s. A boat in the river travels at 3.00 m/s relative to the water. The river is 20.0 m wide with parallel banks. The boat leaves the shore at point A, and point B is directly across the river

51. ## Physics

How would I approach this problem? What formula would I use to answer each part? Thank you in advance for any guidance... As part of the launch of the space shuttle, solid-rocket boosters (SRBs) first take it to an altitude of 45.0 km while they accelerate

52. ## Chemistry

4 super tough chemistry questions: 1.) Water has a considerably higher boiling point and lower vapor pressure than other molecules of similar or larger molar mass. For example, dinitrogen (N2), methane (CH4), etc. all have lower boiling points and higher

53. ## science

Which structure is less likely to suffer damage during an earthquake: a high-rise, steel frame hotel built on sediments, or a wood frame house built on bedrock?

54. ## Math

How would you solve this problem?: x2 + y2 = 25 x2 - y = 5 You have to solve for one variable either by substitution or elimination method and then use the answer to plug it in one of the equations to get the other variable. I've been at this problem for

55. ## Math

Create a polynomial of degree 3 that has x-int at -1, 1, 3

56. ## Chemistry

Given the unbalanced equation shown: _Al+_CuSo4 -> _Al2(SO4)3+_Cu When the equation is balanced using the smallest whole-number coefficients, what is the coefficient of Al?

57. ## Chemistry

Fractional distillation is a technique used to separate complex mixtures of hydrocarbons based on differences in their 1. heats of fusion 2. heats of vaporization 3. melting points 4. boiling points

58. ## engineering

A sign (including its post and base) weighs 40 pounds and is supported by an 18 in by 18 in square base. If the wind applies a force of 13.2 lbs to the sign at the geometric center of the sign surface, will the sign tip over? If so, how much evenly

59. ## Social Studies

I can't seem to figure out this question... Drag and drop the descriptions of events to match conditions in each country following World War II. China Japan Korea Taiwan Communist and anti-communist forces backed by foreign nations went to war here,

60. ## English

Hi! Im comparing and contrasting Urban/Suburban lifestyle in an essay, and i'm having difficulties finding similarities, any ideas?

61. ## English

I just need some help on this one:) Which of these sentences features a possessive noun? a. sentence 1 b. sentence 5 c. sentence 7 (my answer) d. sentence 11 sentence 1: Everything I know about gardening I learned from my good friend Sandy. Sentence 5:

62. ## math

Mrs. Wallace bought 0.75 pound of sliced turkey for \$3.45 and 1.5 pounds of sliced ham for \$6.60. How much more was the turkey per pound than the ham? A.0.20 B.1.20 C.3.15 D.9.00

63. ## Math

How would you go about solving something like sin(5pi/3) without a calculator? Would you use a unit circle?

64. ## Math

Mrs lee was given \$1200 every month for the household expenses . she used 17/24 of it to buy food for the family. 5/7 of the remainder for the clothes and other expenses. She put the remainder money into the bank as savings for the family. Find the amount

65. ## Chemistry

Calculate the binding energy per nucleon (in J) for 6Li and 7Li. The atomic masses are 6.015122 u for 6Li, and 7.016004 u for 7Li. (Enter unrounded values. Assume that the mass of 11H = 1.007825 u, mp = 1.007275 u, mn = 1.008666 u, and me = 0.000549 u,

66. ## Chemistry

Cells use the hydrolysis of adenosine triphosphate, abbreviated as ATP, as a source of energy. Symbolically, this reaction can be represented as ATP(aq) + H2O(l) → ADP(aq) + H2PO4−(aq) where ADP represents adenosine diphosphate. For this reaction ΔG°

67. ## algebra

i need help with the sample work Exponents and Exponential Functions Unit Review

68. ## Chemistry

Rank the following 0.10 M solutions in order of increasing pH. (Use the appropriate symbol to separate substances in the list.) HONH3NO3, HOBr, RbNO3, RbOH, HNO3, HONH2, RbOBr HONH3NO3 (?) HOBr (weak acid, so lower pH value but higher than bases) RbNO3

69. ## chemistry

Q: Calculate the pH of a solution that is 0.56 M HC3H5O3 and 1.28 M NaC3H5O3. I used the H-H equation for this and got this so far: HC3H5O3 acid NaC3H5O3 base pH = pKa + log([NaC3H5O3]/[HC3H5O3]) = -log(Ka of HC3H5O3) + log(1.28/0.56) = -log(1.4*10^-4) +

70. ## chemistry

Calculate the pH after 0.014 mole of gaseous HCl is added to 227.0 mL of each of the following buffered solutions. (Assume that all solutions are at 25°C.) (a) 0.089 M NH3 and 0.17 M NH4Cl (b) 0.74 M NH3 and 1.25 M NH4Cl

71. ## Physics help

find the average acceleration (m/s^2) The formula is a=v2-v1/change in time I don’t understand how to solve this since I only have the average time and distance in (m) for the marble Please explain using steps I’m really stuck

72. ## Chemistry

When 23.5 mL of 0.12 M HCl are added to 50.0 mL of a 0.15 M solution of a weak monoprotic base, the pH of the solution is 10.00. What is the Kb of the weak base?

73. ## Chemistry

If 38.5 mL of 8.9 ✕ 10-3 M HBr is added to 27.0 mL of 4.6 ✕ 10-3 M LiOH, what is the pH of the solution?

74. ## Algebra

Hey, hot question real quick. I am doing Functions in Algebra and I kinda need help. So the function I have is **g(x)=x^2-9** and I have to evaluate **g^-1(x)**, but my question is how does the exponent go in front of the numbers? What does that mean? I

75. ## algebra

Your class is selling boxes of flower seeds as a fundraiser. The total profit p depends on the amount x that your class charges for each box of seeds. The equation p equals negative 0.5 x squared plus 36 x minus 134 models the profit of the fundraiser.​

76. ## Social Studies

Identify which characteristics were associated with Egyptian gods. (Select all that apply) A: Deities were only male. B: Deities controlled all aspects of life. C: Deities could be either kind or hostile toward humans. D: Pharaoh was a god himself. E:

77. ## Algebra

Does the data in the table represent a direct variation or an inverse variation? x - 1, 2, 5, 10 y - 40, 20, 8, 4 A.) Direct variation; y = 40x B.) Inverse variation; xy = 40* C.) Inverse variation; xy = 1/40

78. ## math

Surface Area: 4r^2 41.25^2 S.A= 19.6 inches^2 Volume: 4/3r^3 4/3 1.25^3 V=8.2 inches^3 could someone check my math?

79. ## math

why is a spheres volume to surface area ratio the lowest out of a sphere, cylinder, and a cube? this is part of how im going to do this big project im doing, and i know a sphere has the smallest one, im just not sure why

80. ## math

Which is a better shape for an icecube; a cube, sphere, or cylinder? im thinking cube because then its harder for the sun to get on all sides of it, which would make it melt faster. Does that make any sense?

81. ## history

explain how the Scopes Trial was a reflection of the 1920s cultural clashes and evidence of a changing society

82. ## math

point r has coordinates (a,b). the point is reflected across the x axis and then translated 5 points to the right to create point s. Create an expression that represent the y coordinates of point s

83. ## assets

a person has total assets = 1646.08 calculate the net worth a) 3257.14 b) 33.57 c) -3257.14 d) 1038.10

84. ## Math

Bob took out a bank loan for 60 000 that must be repaid with regular monthly payments of \$1000. The bank charges him an interest rate of 3.0% compounded monthly. How many payments will Bob have to make to pay off the loan? a) 70 b) 59 c) 72 d) 66 I got B

85. ## History

Which of the following statements best summarizes Washington’s viewpoint on American foreign policy? (1 point) The United States can take advantage of Europe’s ambition. The United States should limit interaction with Europe to commerce, or trade.

86. ## Astronomy

How does the size of an object impact gravity? A.) The objects closer to the Sun have more gravity. B.) The smaller the mass of an object the more gravity it has. C.) Size does not impact gravity. * D.) The larger the mass of an object, the more gravity it

87. ## history

Which best reflects the shift in south Carolinas population since the 1950's A. the population has increased and became more urban B. Rural areas have seen greater population growth than urban C. the population of urban areas has decreased. D. urban and

88. ## American government

According to this chart, what is one result of the federal reserve sharply decreasing the discount rate? a. deflation occurs as the economy expands b. deflation occurs as the economy contracts c. inflation occurs as the economy expands******* d. inflatioon

89. ## math

Note: For questions 20 and 21, your teacher will grade your responses to ensure you receive proper credit for your answer. 20. Complete the table. a) 5 6 7 8 9 b) 3.8 4.6 5.4 ? ?

90. ## Social Studies

How would Samuel A. Worcester most likely view the end result of the legal battle between Georgia and the Cherokee people? A.) He would be happy because be wanted the Cherokee to be moved to the west. B.) He would be surprised because he expected the

91. ## American Government

in the case of schenck vs united states justice oliver wendell holmes jr wrote: "the most stringent protection of free speech would not protect a man in falsely shouting fire in a theatre and causing a panic." this is an example of what kind of rights? a.

92. ## SS

For questions 1-10 choose the letter of the answer that matches the description. Not all letters will be used. A. sectionalism B. Missouri Compromise C. Andrew Jackson D. John C. Calhoun E. Articles of Confederation F. cabinet G. tariff H. treason I.

93. ## i want help maths cal

Convert the rectangular equation to an equation in (a) cylindrical coordinates and (b) spherical coordinates. x^2 + y^2 = 16

94. ## help me calculus

Convert the rectangular equation to an equation in (a) cylindrical coordinates and (b) spherical coordinates. 4(x^2 + y^2) = z^2

95. ## Physics

An empty SG bottle weights 25 g.When filled with water completely it weights 55 g and with alcohol it weights 48 g. Find the RD of alcohol A numerical

96. ## math

Find an equation of the circle that has center (-3,6) and passes through (4,-1)

97. ## algebra 2

Reuben deposited \$2000 into an account with a 3.8% annual interest rate, compounded semiannually. Assuming that no withdrawals are made, how long will it take for the investment to grow to \$3000?

98. ## English

identify the portion that contains a compound subject during the 1940s and 1950s , Dudd Abbott and Lou Costello were a popular comedy team on radio, televison ,and sage a. 1940s and 1950s b. Bud Abbott and Lou Costello ..... c. radio, televsion, and stage

99. ## American government

Which answer best describes why some view the senate as undemocratic? The vice president is the leader of the senate.***** The senate and the house don't have the same powers. Everyone living in the state can can vote for that states Senate regardless of