# jhon

Popular questions and responses by jhon
1. ## math

cotx+tan2x=cotxsec2x prove

2. ## English

Which adjective best describes the community's attitude toward Mari Djata's inability to walk in Sundiata? A. fearful B. indifferent C. sympathetic D. mocking B?

3. ## Chemistry

How much energy in kilojoules is released when 25.0 g of ethanol (C2H5OH) vapor at 93.0 C is cooled to -10 C? Ethanol has mp = -114.1 oC, bp = 78.3 oC, ΔHvap = 38.56 kJ/mol, and ΔHfus = 4.93 kJ/mol. The molar heat capacity is 112.3 J/(K.mol) for the

4. ## chem

A 0.069 gram sample of a metal reacted with HCl and produced 45.31 mL of H 2 gas at 25¡ÆC and 1 atm pressure. The metal is known to react with HCl according to the following reaction, 2 M + 6 HCl > 2 MCl 3 + 3 H 2 What is the molar mass of the metal?

5. ## Math

A radioactive substance decays exponentially. A scientist begins with 130 milligrams of a radioactive substance. After 20 hours, 65 mg of the substance remains. How many milligrams will remain after 24 hours?

6. ## Chemical Engineering

How much acetone liquid (in mls) is required to produce a vapor concentration of 200 ppm (parts per million) by volume in a room of dimensions 3 x 4 x 10 meters? The temperature is 25oC and the pressure is 1 atm. The following physical property data are

17. ## i really need help but dont know how to do it

Taylor made a scale drawing of his room using a scale of 0.25 inch = 1 foot. On the drawing, the length of his room is 3.25 inches and the width is2.75 inches. What is the area of Taylor’s actual room? A. 36 square feet B. 48 square feet C. 143square

18. ## physics

a 20 kg traveler's bag is being pulled along the floor with a force of 50 NF. the force is applied on the handle forming an angle of 30 degree with the horizontal. neglecting friction,what is the acceleration og the bag? How much force is exerted by the

19. ## chem

Fe + O2--->Fe2O3 How many grams of iron are required to convert 80 mL of oxygen at STP?

20. ## Young Harris College

How much energy is needed to heat 8.50 g of ice from -30.0 C to 70.0 C? The heat of fusion of water is 6.01 kJ/mol, and the molar heat capacity is 36.6 J/(mol.K) for ice and 75.3 J/(mol.K) for liquid water. I got 19.24kJ but it isn't correct!!

21. ## math

Many people are trying to reduce their carbon footprint. Amrita’s carbon footprint this year was 85% of last year’s footprint. If her carbon footprint this year is 34 tonnes,what was her carbon footprint last year? PLZ NEED HELP

22. ## physics

A motorboat travels due north at a steady speed of 3.0 m/s through calm water in which there is no current. The boat then enters an area of water in which a steady current flows at 2.0 m/s in a southwest direction, as shown in the next picture. Both the

23. ## garyson

A person rides up a lift to a mountaintop, but the persons ears fail to pop –that is, the pressure of the inner ear does not equalize with the outside atmosphere. The radius of each ear drum is 0.40×10ˆ-2m. The pressure of the atmosphere drops from

24. ## chemistry

Molecular shape of BrF3 by VSEPR theory

25. ## Algebra

Write the number 7.1\times 10^{4}7.1×10 4 in standard form.

34÷ 45=_

27. ## math

Compare each pair of numbers. Use . greater than 3/5 and 5/8

28. ## Algebra

A cashier has only one dollar bills, quarters,and dimes. List all the ways you could receive $2.50 in change$1 Bills Quarters Dimes Ex. 2 2 0

29. ## econ

Which best describes interest?

30. ## math

In five games, you score 16, 12, 15, 13, and 17 points. How many points must you score in the sixth game to have an average of at least 15 points?

31. ## science,physics

a 5kg bomb exploded into two fragments .If one fragment with 3 kg moves in a direction with 5m/s then what is the velocity of the second fragment of mass 2kg

32. ## history

what about Mohawk interactions with the europeans

33. ## computer Science

1. Create a program which will allow the user enter ten numbers. The program is to count how many numbers were above 50. Hint: You will need to incorporate a Selection (If…then) statement.

38. ## math help

Mrs. Williams is going to purchase a plastic cover for her outdoor fish pond. The area of the fish pond is 25 m2. However, she must purchase a cover that is 12% more than the pond area in order to cover the entire edges of the pond. The plastic cover costs

41. ## Math

An electric dentist chair lifts ruth,110,0.3 meters in 10 seconds what is the power developed by this chair?

42. ## ALGEBRA

A rectangular garden is 30 ft wide. If its area is 2700 ft{}^2, what is the length of the garden?

43. ## trigonometry

find the radius of a circle in which a 59 foot chord subtends an angle of 12 degree at the center

44. ## chemistry

Hess¡¯ law says that when we add reactions together we can also add the enthalpies. Given the following set of reactions, use Hess¡¯ Law to calculate the enthalpy of the reaction given below. N2H4 + H2 ¡æ 2 NH3 ¥ÄH¡Æ = ? N2 + 3 H2 ¡æ 2 NH3

45. ## chemistry

The following experimental data were obtained for the reaction; 2 NO + 2 H2 ¡æ N2+ 2 H2O Rate/10-5M/s [NO]/10-2M [H2]/10-2M 0.50 0.50 0.20 2.00 1.00 0.20 0.25 0.25 0.40 Write a rate law in agreement with the data. Rate = What is the value and units of

46. ## physics

a 20 kg traveler's bag is being pulled along the floor with a force of 50 NF. the force is applied on the handle forming an angle of 30 degree with the horizontal. neglecting friction,what is the acceleration og the bag? How much force is exerted by the

47. ## chemistry lab

If a portion of your aspirin sample had broken down, how would that effect the total amount of base used? What would the effect be on the percentage of aspirin in your sample?

48. ## physics

If you wanted to make a barometer that had a column of liquid about 6 feet tall, what would the density of the liquid have to be? 1 meter = 3.28 ft 1 inch = 2.54 cm Density Hg = 13.6 g/mL 1atm = 760 torr

49. ## chemistry

If you wanted to make a barometer that had a column of liquid about 6 feet tall, what would the density of the liquid have to be? 1 meter = 3.28 ft 1 inch = 2.54 cm Density Hg = 13.6 g/mL 1atm = 760 torr

50. ## logic

a team of Andres Bruno carlos Daniel and Esteban participated in a tennis doubles tournament so two of one team play against other two It is known that Andres participated in a game Bruno in 2 carlos in 2 Daniel in 3 and Esteban in 4 then the amount of

51. ## logic

CLaudia has 4 task to do go to the market, study, clean , sport it is known - go to the market if study - study if she does not clean - if she does not clean then she goes to the market a 15% b 12% c 10% d 24%

52. ## logic

a survey of three marks of soda has -of 100 people 83 drinks at least 1 of 3 marks -54 just drink 1 -19 drinks 2 of 3 between the people the % that drink the 3 are a 15% b 12% c 10% d 24%

53. ## logic

100 days after a sunday will be a day a Sunday b Tuesday c thursday d monday

54. ## logic

In a soccer tournament between four teams A,B,C,D wich was free for all the scores were A 4 points B 4 points C 3 points D 1 point In this tournament the winner gets 2 points, the draw 1 point the looser 0. It is known that each team has a goal so. 1 The

55. ## logic

in a bike competition with 21 laps was observed that 13% quit before 5 laps, 17% quit later than 5 laps but less than 15, and the others 210 finished the competition the number of bikers that quit before the 5 lap were: a) 27 b) 39 c) 43 d) 56

56. ## logic

the rectangle represented the AB side is 4cm the side BC is 6 cm i want to build a triangle taking the AB segment and the third vertice inside the triangle so his area becomes higher than 8 cm*cm. the area in cm*cm of the region of the rectangle in which

57. ## logic

the rectangle represented the AB side is 4cm the side BC is 6 cm i want to build a triangle taking the AB segment and the third vertice inside the triangle so his area becomes higher than 8 cm*cm. the area in cm*cm of the region of the rectangle in which

58. ## classical mechanics

A Venturi flow meter is used to measure the the flow velocity of a water main. The water main has a diameter of 40.0 cm, and the constriction has a diameter of 20.0 cm. The two vertical pipes are open at the top, and the difference in water level between

59. ## Logic

Claudia has four home works to do, go to the market, study for the exam, clean the room, and practice sports, she knows that: -she goes to the market if she studies for the exam. -she studies for his exam if she does not clean his room -if she does not

60. ## math

Please show all of your work in the space below. Please present and organized and complete solution. A garden will be made up of a parallelogram, a rectangle and a triangle. The garden must have an area of 500m square. Draw two possible gardens. Determine

61. ## physics

a pitching machine throws a baseball at a batter with an initial velocity of 22.0 m/s at an angle of 30 degrees to the horizontal. the ball is 1.60 m above the ground when it is pitched. a) if the batter hots the ball at the same height as it was launched

62. ## calculus(related rates)

Water is leaking out of an inverted conical tank at a rate of 12200 cubic centimeters per minute at the same time that water is being pumped into the tank at a constant rate. The tank has height 15 meters and the diameter at the top is 6.5 meters. If the

63. ## math

a drawing of a deck has a scale of 1 inch to 5 feet. the actual deck is 18 feet long.how long is the deck in the scale drawing?

64. ## calculus

the dimensions of a closed rectangular box are measured as 30 in, 40 in.. and 60 in.. with a maximum error of 0.2 in. in each measurement. use differentials to estimate the maximum error in calculating the volume of the box

65. ## calculus

find the approximate change in z when the point (x,y) changes from (1,1)to (1.01, 0.90) f(x,y) = xe^(-y) + ye^(-x)

66. ## Chemistry

If a 2.6 g of weak diprotic acid were dissolved in 100 mL of water and a 10 mL aliquot of this solution required 21.6 mL of 0.1 M NaOH to reach the first endpoint, what are the equivalent and formula weights of H2A? I think I first need to find the moles

67. ## English

Is it self plagerism if I take the same argument or main idea from a paper that I wrote last semester and use that same principle/argument/main idea/thesis in another paper for the next semester if it's is completely rewritten with different words and

68. ## Computer Science (MATLAB)

Given an arbitrary one dimensional vector v imputed by the user for example v='Helllllloooooo' or v='Helo' I was able to append empty characters onto any one dimensional vector that the user can enter so that way the total length of the vector is a

69. ## Computer Science (MATLAB)

I had a test in my computer science course in which I was asked if any while loop can be replaced with a for loop. I put true. I guess the answer was false. My professor said that if you had a while loop in which you asked the user to input a certain value

70. ## Computer Science (MATLAB)

I had a test in my computer science course in which I was asked if any while loop can be replaced with a for loop. I put true. I guess the answer was false. My professor said that if you had a while loop in which you asked the user to input a certain value

71. ## Computer Science (MATLAB)

Given a vector of values of zeros and ones such as [1 0 1 0 0 0 1 0] I'm asked to, given a probability provided by the user, use that probability to change the values in the vector using that probability. For example given the vector [0 1 0 0 0 1 0 0 0 1]

72. ## English

Hi, I'm writing a paper for English and my professor crossed off the authors name in one of quotes for the citation of my rough draft as if it was suppose to be there. Something like xxxxxxxxxxxxxxxxxxxxxx (john 59) and she crossed off john as if I wasn't

73. ## science

the last question i do not get can one of y´all help me out lisa is working on a science project her task is to answer the question ¨does rogooti(which is a commerical hair product) affect the speed of hair growth control group: independent variable:

74. ## science

can you tell me a website on elements

75. ## science

Can you give me awebsite about phase change?

76. ## science

Can you give me a website about attoms

77. ## science

Where can I find some information about nourvis system and endocrine system?

78. ## Normal distribution

The breaking strength of cable is known to be normally distributtes with a mean of 4000 kg and a standard deviation of 25 kg.The manufacturer prefers that at least 95% of his product meet a strength requirement og 4050 kg.is that requirement being met?if

79. ## social studies

Where can I find some information about native americans

80. ## 9 th grade geomitry

how do you do 19= n - 9 ??????

81. ## Perimeter

Draw a figure with a perimeter of 24, using 11 squares

82. ## Perimeter

Draw a figure with a perimeter of 24 squares, using 21 squares

Is it possible to find a antonym for a noun

84. ## physical science

How much work is done by the gravitational force on an object of mass 9.40 kg that is initially at rest when it falls down for a time of 1.85 seconds. Ignore air resistance

85. ## sociology

How does conflict theory and functionalist theory apply to conditions and compensations of the workers in Barbara Ehrenreich's "Nickle and Dimed"?

1. ## algebra

It’s really hard

posted on April 15, 2019
2. ## Social studies

That's you're correct! It helps alot!

posted on February 8, 2019
3. ## math

Hello, I'm sorry but I got a 6/17 and this is totally not okay. I was checking my answers and totally changed them because of this and it did not work at all. These answers are completely wrong

posted on May 8, 2018
4. ## ENG1010

b

posted on March 18, 2018
5. ## algebra

solve 4(7x - 4) = 124

posted on November 20, 2017
6. ## Math

a 100 pound person would weigh 20 pounds on lo, a moon of jupiter. a person weighing 150 pounds would weigh 25 pounds on the moon. use ratio tables to determine which moon would make a person weigh the most

posted on November 15, 2017
7. ## Physics

fdf

posted on August 27, 2017
8. ## Social Studies

he is right

posted on April 25, 2017
9. ## English

If a writer wanted to put emphasis on the person doing an action, which of these statements would be the best choice? A) active voice B) passive voice C) subjunctive mood D) interrogative mood

posted on April 8, 2017
10. ## Language Arts

thanks i play mincraft

posted on March 29, 2017
11. ## LA HELP/CHECK!

yes these are all correct

posted on March 27, 2017
12. ## math

yes its true

posted on January 30, 2017
13. ## geometry

Given m = 10 and n = 9, the ratio of n to m is 10/9. True False

posted on January 24, 2017
14. ## math

Actually it is 2.07 because 17.97+25.49 is 43.46 and 43.46+0.33 is 43.79 then subtract 50.00 and 43.79 then you divide 6.21 from 3 and you will get 2.07

posted on December 8, 2016
15. ## history

happyness

posted on April 18, 2016