albert

Most popular questions and responses by albert
1. Chemistry

when 25.0 mL of a solution containing both Fe2+ and Fe3+ ions is titrated with 23.0 mL of 0.0200 M KMnO4 (in dilute sulfuric acid). As a result, all of the Fe2+ ions are oxidized to Fe3+ ions. Next, the solution is treated with Zn metal to convert all of

2. Physics Help!

A skier wants to build a rope tow to pull herself up a ski hill that is inclined at 15 with the horizontal. Calculate the tension needed in the rope to give the skier's 54kg body a 1.2 m/s^2 acceleration.

3. Chemistry

How do you differentiate between fluorene and acetanilide? Suggest procedures and steps involved other than melting point and chromatography.

4. physics

Suppose the straight-line distance between New York and San Francisco is 4.4 106 m (neglecting the curvature of the earth). A UFO is flying between these two cities at a speed of 0.69c relative to the earth. What do the voyagers aboard the UFO measure for

5. Chemistry

How do you distinguish between fluorene and acetanilide? Suggest methods other than melting point and chromatography.

6. math

which values can be substituted for x to make the inequality x - 4 >0 true? choose all that apply A. 0 B. 3 C. 4 D. 18 my answer is 0 and 4 please check my answer's

7. math

9. which set of output values correctly completes the function table? y=6-x input (X) output (y) -2 ? -1 ? 3 ? ----------------------- 4,5,3 -8,-7,3 8,7,3 11. What is the function rule shown by the table? input(x) output(y) -2 -3 0 1 1 3 2 5

8. Finance

Evans Technology has the following capital structure. Debt ............................................ 40% Common equity .......................... 60 The aftertax cost of debt is 6 percent, and the cost of common equity (in the form of retained earnings)

9. physics

a turntable rotates about a fixed axis, making one revolution in 10s . the moment of inertia of the turntable about it's axis is 1200kg/m^2 . a man of mass 80kg , initially standing at the center of the turntable, runs out along a radius. what is the

10. Life orientation

Critically discuss six ways in which individual,groups and broader of South African community can be influenced by humans rights violations

11. Chemistry

The reaction NO2(g) + NO2(g) → N2O4(g) is second order with a rate constant of 0.044 /M·s at a particular temperature and pressure. If the initial concentration of NO2(g) is 0.100 M, what is the concentration of NO2 after 20 minutes?

12. Chemistry

What should the molar concentrations of benzoic acid and sodium benzoate be in a solution that is buffered at a pH of 4.75 and has a freezing point of -2.0 ∘C? (Assume complete dissociation of sodium benzoate and a density of 1.01 g/mL for the solution.)

13. science

find the gravitational force exerted by the sun on a 70 kg man located at the earth's equator a)at noon when the man is closest to the sun. b)at midnight when he is futherst from the sun. c)calculate the diferrence in gravitational acceleration due to the

14. Chemistry

Please help me set up these problems. I have been staring at them for hours and I can't tell where I went wrong. Question: Consider the following reaction: CaCO3(s)→CaO(s)+CO2(g). Estimate ΔG∘ for this reaction at each of the following temperatures.

15. math

if the interest rate is 8.25% and you borrowed \$5000 for 30 days. How much interest would you pay

16. Mathmeta

How to select logical numbers for mark six?

17. Chemistry

To what decimal place should each answer be rounded? and how many significant figures does the rounded answer have? a) 9cm + 2.8 cm= 11.8cm (unrounded) b) 0.135 atm + 0.6 atm= 0.735 atm (unrounded) PLEASE HELP

18. RIGHT TRIANGLE TRIG

a kite is being flown 150 yards of string. the kite has an angle of elevation with the ground 65 degrees. how high above the ground is the kite. I DON'T KNOW HOW TO SET UP THE PROBLEM

19. Physics

A train accelerates from the rest at the station A at a rate of 0.8 m/s2 for 25 s, the travels at constant velocity for 77.5 s before it comes to rest at the station B after period of retardation lasting 20 s. What is the distance between stations A and B,

20. trigonometry

from a point 3 m above the water surface, the angle of elevation of the top of a certain tree is 30°40', while the angle of depression of its image is 65°10'. Find the height of the tree and its distance from the point of observation.

21. Physics

A block initially at rest, slides down from the top of an inclined plane 30degrees above the horizontal. The plane is 100feet long and frictionless. what distance will it travel on a frictionless horizontal surface at the foot of the plane 6seconds after

22. college physics

calculate the specific heat of 200g of substance whose temperature is 30 degree celcius if it is mixed with 200g of water heated in a 300g iron container at 100 degree celcius. the final temperature of the mixture is 98 degree celcius.

23. Math

k such that 3 is the remainder when f(x)=x to the 4 power minus 4xcube minus 8xsquare minus 7x plus 1. Tapos which of the following binomial factor of 2xcube plus 5xsquared minus 10x plus 16.

24. THEORY OF INTEREST

Suppose that a money market fund pays a nominal rate of interest of 8.7 percent convertible monthly. What is the equivalent nominal rate convertible quarterly?

25. Physics

The free-fall acceleration on Mars is 3.7 m/s2. (a) What length pendulum has a period of 4 s on the earth? cm What length pendulum would have a 4 s period on Mars? cm (b) A mass is suspended from a spring with force constant 10 N/m. Find the mass suspended

26. stat

Forty-nine items are randomly selected from a population of 500 items. The sample mean is 40 and the sample standard deviation 9. Develop a 99% confidence interval for the population mean

27. TRIG WORD PROBLEMS

from 25 feet away from the base of a building, the angle of elevation from the ground to the top of a building is measured 38 degrees. how tall is the building. WHat i did was put 25 feet on the base of the triangle the angle measurement oppsite and the

28. Physics

A skier wants to build a rope tow to pull herself up a ski hill that is inclined at 15 with the horizontal. Calculate the tension needed in the rope to give the skier's 54kg body a 1.2 m/s^2 acceleration.

29. Physical Science

If the density of ice is 0.92 g/cm^3, what percent of an ice cube’s (or iceberg’s) mass is above water.

30. Math

When you solve the system shown by the elimination method, which statement is true? y + 3x = 10 −y − 3x = 10 A. You eliminate y; the sum of the coefficients of y is zero. Then, you can solve for x. B. There is no solution; x and y are eliminated and

31. Chem

To what decimal place should each answer be rounded? and how many significant figures does the rounded answer have? a) 9cm + 2.8 cm= 11.8cm (unrounded) b) 0.135 atm + 0.6 atm= 0.735 atm (unrounded) can you show me how to do this?

32. algebra

A man and a woman's ages total 98. He is twice as old as she was when he was her age now. What are their ages?

33. maths

The variation in size from year to year of a particular population can be modelled by an exponential model with annual proportionate growth rate 0.1246. The size of the population at the start of the initial year is 360. Choose the TWO options that give,

34. Math

A very large book has pages numbered from 1 to 11521. How many times is the digit 3 printed?

35. college physics

calculate the specific heat of 200g of substance whose temperature is 30 degree celcius if it is mixed with 200g of water heated in a 300g iron container at 100 degree celcius. the final temperature of the mixture is 98 degree celcius.

36. maths

The variation in size from year to year of a particular population can be modelled by an exponential model with annual proportionate growth rate 0.1246. The size of the population at the start of the initial year is 360. Choose the TWO options that give,

37. maths

The method for completing the square can be used to write the expression −2x^2 + 12x−5 in the form a(x + b)^2 + c, where a, b and c are constants. Choose the option that gives the value of c. Options A −23 B −13 2 C 5 2 D 3 E 13 F 14

38. maths

Choose the option that gives an expression for the indefinite integral ʃ (cos(4x) + 2x^2)(sin(4x) − x) dx. In each option, c is an arbitrary constant. Options A cos(4x) + 2x^2 +c B -1/8cos(4x) + 2x^2)^2 +c C 1/4 (sin(4x) − x)^2 + c D (1/(2 (sin(4x)

what is mental math and how does it work. the question is use mental math to find the missing numbers. look for the pattern in each chart.the chart ooks like eight boxes two rows of four, the filled in is 0,1,2,3,4the second row is empty, the second

40. Math

Solve the system using substitution. 6x + y = 12 4x + 6y = −8 A. (2 1/2,3) B. (−2 1/2,−3) C. (2 1/2,−3) D. no solution I GOT B!

41. Chemistry

I'm doing a redox potential/lead acid cell experiment and one of the questions that were asked was: -What were the identities of the gases you saw being produced at the + and - electrodes during the cell conditioning process? We used H2SO4 How do I go

find dy/dx by implicit differentiation a) xy + x^5y^2 + 3x^3 - 4 = 1 b) lny = cos x thank you

43. maths

A sequence is defined by un = 2×(−0.5)n + 3 (n = 1,2,3, . . .). Choose the option that best describes the long-term behaviour of the sequence. Options A un becomes arbitrarily small (that is, un → 0 as n→∞). B un becomes arbitrarily large and

44. maths

The mean weight of the contents of samples of 30 bags of sugar has standard error 0.008kg. Choose the option that is closest to the probability, to three decimal places, that the mean weight of the contents of samples of 30 bags of sugar will be 1kg or

45. maths

Choose the option that gives the solution of the initial-value problem dy dx=(1 + 2 cos2x^2)/y (y > 0), y= 1 when x = 0. Options A y = 1+ 2sin^2 x B y = (1 + 2 sin x)^2 C y = (4x + cos(2x))^2 D y = 4x + cos^2 x E y =sqrt(4x + cos(2x) F y =sqrt(1 + 4x +

46. statistics

The heights in centimetres of men in a sample selected at random may be modelled by a normal distribution with mean 180.5 and standard deviation 11.3. 1. Choose the option that is closest to the value above which 30% of the heights of men will lie. Options

47. Physics

A man enters a tall tower, needing to know its height. He notes that a long pendulum extends from the ceiling almost to the floor and that its period is 28.0 s. (a) How tall is the tower? m (b) If this pendulum is taken to the Moon, where the free-fall

48. Physics

g=4 pi (l/t square)

49. Math (calculus 3)

A football is thrown down the field by a quarterback from a height of 1 foot with an initial velocity of 40 feet per second at angle of pi/6 radians. If a receiver catches the ball downfield at a height of 1 foot above ground; a) How long was the ball in

Phisic

51. Chemistry Physics

How many grams of water at 20°C are necessary to change 800g of water at 90°C to 50°C?

52. theory of interest

1.Two investments are made at the same time. The first consists of investing 1550 dollars at a nominal rate of interest of 7.9 percent convertible semiannually. The second consists of investing 1450 dollars at a nominal rate of interest of 7.9 percent

53. ACT Math

Carlos goes to a local deli for lunch and orders a sandwich. He needs to choose a bread, a meat, a vegetable, a cheese and a source. How many sandwich combinations are possible? Assume Carlos always pick only one item from each category. Bread: Italian,

54. English Analysis

Reading The Stranger by the lovely Albert Camus. Just need help understanding this question: -After I listed some themes I explored, my teacher asks: "Given the themes you listed, are any conventions questioned based on the treatment of a given theme?

55. Implicit differentiation calculus

PLEASE HELP , I DON'T UNDERSTAND find dy/dx by implicit differentiation a) xy + x^5y^2 + 3x^3 - 4 = 1 b) lny = cos x thank you

56. maths

The variation in a population is modelled by the recurrence relation (Jn+1 0.9257 0.0208) (Jn) + (0.014) (An+1 0.0661 0.9767) (An) (0.056) where Jn and An are the sizes, in millions, of the subpopulations of juveniles and adults, respectively, n years

57. maths

f(x)=ln(e^x-e^-x), x>0 By applying in turn the Composite and Quotient Rules, find derivative and second derivative. Thanks.

58. maths

The mean weight of the contents of samples of 30 bags of sugar has standard error 0.008kg. Choose the option that is closest to the probability, to three decimal places, that the mean weight of the contents of samples of 30 bags of sugar will be 1kg or

59. maths

By first applying the Product Rule, choose the option that gives (correct to two decimal places) the overall maximum value of the function f(x) = e^3x cos(2x) on the interval [1/12 π, 1/4π]. Options A 0.49 B 1.90 C 2.19 D 2.42 E 3.97 F 5.88 G 7.46 H

60. maths

Choose the option that gives (correct to two decimal places) the area of the region which is bounded by the x-axis and by the graph of y =(20(7 − x)(x − 3))/x^2 . Options A 0.47 B 1.31 C 2.09 D 3.76 E 5.12 F 6.55 G 8.20 H 9.46

61. maths

The mean weight of the contents of samples of 30 bags of sugar has standard error 0.008kg. Choose the option that is closest to the probability, to three decimal places, that the mean weight of the contents of samples of 30 bags of sugar will be 1kg or

62. math

The ticket prices for a movie are shown in the illustration. Receipts for one showing were \$1,930 for an audience of 205 people. How many general admission tickets and how many senior citizen tickets were sold?

63. trigonometry

can someone help me prove the identities on this: 1- 1/2 sin2θ = sin^3θ + cos^3θ / sinθ + cosθ

64. trigonometry

sina^2θcos^2θ= 1/8 (1-cos4θ)

65. Math

Solve the system using substitution. y = 4x − 5 y = 2x + 1 A. (−2, −3) B. (1, 3) C. (−2, −13) D. (3, 7)

find the slope of the tangent line to y^4 = 3x^2 - 2x at the point (1,1)

67. math

\$24 lft a 15 percent tip how much total

68. trig

1.Ifg(x)=cos4x,find g'(pie/24). 2.Differentiate y=csc^2 pie*x

69. maths

The mean weight (1.0042kg)of the contents of samples of 30 bags of sugar has standard error 0.008kg. Choose the option that is closest to the probability, to three decimal places, that the mean weight of the contents of samples of 30 bags of sugar will be

70. maths

The mean weight of the contents of samples of 30 bags of sugar has standard error 0.008kg. Choose the option that is closest to the probability, to three decimal places, that the mean weight of the contents of samples of 30 bags of sugar will be 1kg or

71. maths

A sequence is defined by un = 2×(−0.5)n + 3 (n = 1,2,3, . . .). Choose the option that best describes the long-term behaviour of the sequence. Options A un becomes arbitrarily small (that is, un → 0 as n→∞). B un becomes arbitrarily large and

72. maths

The mean weight of the contents of samples of 30 bags of sugar has standard error 0.008kg. Choose the option that is closest to the probability, to three decimal places, that the mean weight of the contents of samples of 30 bags of sugar will be 1kg or

73. physics

how fast will a object be traveling when drppped from 30 feet high

74. math163

Please i need all the process.. thank you.. for the polynomial, list each real zero and its multiplicity. determine whether the graph crosses or touches the x-axis at each x-intercept. f(x)=1/2x^4(x^2-5)(x+1)

75. math-163

for the polynomial, list each real zero and its multiplicity. determine whether the graph crosses or touches the x-axis at each x-intercept. f(x)=1/2x^4(x^2-5)(x+1)

76. chemistry

A HOT CUP OF COFFEE HAS SOME SUGAR COMLETELY DISSOLVED IN IT. AFTER THE COFFEE HAS COOLED, SOME SUGAR APPEARS AT THE BOTTOM OF THE CUP. EXPLSIN WHAT HAS HAPPENED IN TERMS OF SATURATION.

i need all the prime numbers of 1-100

78. science

how does the mantle material get energy to move in convection currents?

79. PhYsIcS

A 5 meter, 100 N/m spring is at a 30 degree angle to the horizontal. If a 10 kg weight is placed on the spring when it is compressed 2 meters, how high will it travel?

80. PRE calculus

Find the area between each curve and the x-axis for the given interval. y=6x^2+5 from x=0 to x=5 I'm just starting to learn about this and am very confused. Can someone show me how to do this. Thanks. I need help.

81. Specialist Mathematics

Need help with three proofs. Proof#1: Prove that |x+y| is less than or equal to |x|+|y| Proof#2: Prove that |x|-|y| is less than or equal to |x-y| Proof#3: Prove that |x+y+z| is less than or equal to |x|+|y|+|z|.

82. Physics

Hello, I need some help with this physics problem. This was the only one I couldn't solve, and the teacher wouldn't help me because she wanted me to figure it out for myself, just like everyone else tried. (Although no one did) Here is the question: Type

83. Math

A wheel makes6 1/12 revolution per minute. If it rotates 45 minutes,how many revolutions does it make

84. Math

Solve the system using substitution. x = y − 6 y = 6 − 3x A. (0, 6) B. (6, 0) C. (0, −6) D. (−6, 0)

85. math

convert 40.0m^3 to liters. note that 1mL = 1cm^3. can you show me how to do this problem?

86. Algebra

The number of items on two grocery list differs by seven.the total number of items is 33 how many items on each list

87. physics

A ball of mass M1 moves with a velocity U1, collides perfectly elastically with a stationary ball of mass M2 . After the collision, M1 and M2 move with velocities V1 and V2 respectively. Show that : V1 =(M1-M2) / (M1 + M2 ) * U1 .

Identify the infinitive and classify whether it is used as a subject, direct object, predicate noun, appositive, and object preposition.  1.Her only thought was to win.  2.My desire is to help.  3.Mrs. Cao loves to crochet.  4.They remember to say the

89. Economics

What are welfare payment or consumer?

91. Polynomials

Can someone please help me get the sum difference and product of this problem I am so lost x^3+ 2x-5∶ x^4-x^3+ 3x^2- 2x+3

92. math

During an art contest at your school, you and a classmate each won blue ribbons for 1/3 of the pieces you entered in the contest. You won 2 blue ribbons and your classmate won 3 blue ribbons. Explain how this could be.

93. Algebra

Please let me know if I answered these correctly. thank you, #2. Add: 3p^2 – 5p – 4 and 9p^2 + 10p – 2 A. 12p2 + 15p – 6 B. 12p2 + 5p – 2 C. 12p2 + 5p – 6 D. 12p2 + 15p – 2 answer D ________________________ #7. (3x^2 – 2x – 1)(x^2 + x +

94. college physics

what is the force applied in the direction of the wire at a point attached to the patient in a traction system if the mass applied ius equal to 5kg.?

95. College Algebra

A rectangle field with area of 1,500,000 needs to be fenced. 2W+2L=5,000. solve for L and W

96. Chemistry

calculate the energy associated with a photon whose wavelength is 14.5*10^-8cm.

97. maths

The mean weight (1.0042kg)of the contents of samples of 30 bags of sugar has standard error 0.008kg. Choose the option that is closest to the probability, to three decimal places, that the mean weight of the contents of samples of 30 bags of sugar will be

98. maths

The variation in a population is modelled by the recurrence relation (Jn+1 0.9257 0.0208) (Jn) + (0.014) (An+1 0.0661 0.9767) (An) (0.056) where Jn and An are the sizes, in millions, of the subpopulations of juveniles and adults, respectively, n years

99. maths

The variation in a population is modelled by the recurrence relation (Jn+1 0.9257 0.0208) (Jn) + (0.014) (An+1 0.0661 0.9767) (An) (0.056) where Jn and An are the sizes, in millions, of the subpopulations of juveniles and adults, respectively, n years