Riana

Most popular questions and responses by Riana
1. math

A certain antibioyic reducesthe number of bacteria in your body by 10% each dose a) if four doses of the antibiotic are taken, what percent of the original bacterial population is left. b) biologists have determined that when a person has a bacterial

2. math

how to determine the acute angle between the line 2x+3y=6 and the y axis?

3. math

bricks are stacked in 20 rows such that each row has a fixed number of bricks more than the row above it. the top row has 5 bricks and the bottom row 62 bricks. how many bricks are in the stack?

4. physics

a car starts from rest , attains a velocity of 36kmph with an acceleration of 0.2m/s^2 travels 9km with this uniform velocity and then comes to halt with a uniform acceleration of 0.1m/s^2 find the total time of travel of the car.

5. ELA

What are character trait for Moon Shadow from Dragonwings but written in an acrosric poem way?

6. math

first term of the arithmetic sequence is 13. two other terms of the sequence are 37 and 73. common difference is consecutive terms integers. determine all possible values for 100th term.

7. math help!

a hockey arena has a total seating capacity of 15690.the first row of seats around the rink has 262 seats. the number of seats in each subsequent row increases by 18. how many rows of seats are in the arena?

8. PHYSICS'S

How much heat would it take to change 1.0kg of water at 20°C to steam at 110°C. I can't get the right answer that is 2.6×10^6J. Please tell me how can I solve this problem, I want to learn how to solve These problem plz help me.

9. chemistry

25g of NaCl is deissolved in 100g of water. what is the concentration in percentage by mass?

10. chemistry

Element x is composed of isotopes x-56 mass 56.0 u and x-59 mass 59.0 u. What is the percentage abundance of each of these isotopes if the atomic mass is 57.3 u?

11. chemistry

A saturated solution of kno3 at 70°c is cooled to 10°c. What mass of a solid of precipitate out of solution.

12. Math

Someone please help me, I do not understand how to solve this problem: Let x be a random variable representing dividend yield of bank stocks. We may assume that x has a normal distribution with σ = 2.0%. A random sample of 10 bank stocks gave the

13. math

the population of a town is declining at a rate of 4.1% per year. the current population is 25000. 1)what will the population be in 7 years. 2) how long will it take the population to reach 15000?

14. math

t8=1024 and decrease by 2/3. what will be the sum of the first 7 term. i don't know what shud i do first to solve it.

15. Physics

what can be the source of error in lab of forces equilibrium,force board lab?

16. Math

Here is the question:Consider a data set of 15 distinct measurements with mean A and median B. (a) If the highest number were increased, what would be the effect on the median and mean? Explain. The mean would remain the same while the median would

17. chemistry

how to find the pressure exerted by the hydrogen alone? and the volume of dry hydrogen at SATP? i have room temperature=23C room pressure =101.62kPa volume of h2 gas & H2O vapour collected =43.2ml temperature of water = 23C length of Mg ribbon = 3.00cm

18. Math

The sum of two numbers is 70. When the smaller number is subtracted from the bigger number, the result is 24. Find the numbers.

a small airplane is dropping a probe in a remote area in antarctica in a narrowly specified location. the probe in a protective shell can not land any harder than with a maximum speed of 60m/sec at landing, while the plane has to move at a minimum speed of

20. chem

Why is it expected that 2/10 of the ejected electrons will cone from the n=1 shell, and 8/10 ofthe electron from the n=2 shell?

21. chemistry.....help plz

what is the density of methane gas at 20 degree and 115kpa?

22. Physics

the distance between two successive crests in waves is 1.50m, and the source generates 25 crests and 25 troughs in 5.00sec. what is the speed of the waves?

23. chemistry

what is the density of methane gas at 2o degree and 115kpa?

24. physics

a bullet initially moving with a velocity 20m/s strikes a target and comes to rest after penetrating a distance 10cm in the target calculate the retardation/deceleration caused by the target.

At a nuclear power plant water at 8°c from a lake is used in a heat exchanger to condense spent steam at a temperature of 120°c,to water at 85°c before it is recycled to the reactor. If the cooling water returns to the lake at a temperature of 19°c,how

26. biology

why are yeast classified as eukaryotes? i know they are in kingdom fungi and all the members are eukaryotes but why?

27. English

In the book Dragonwings, after saving Black Dog's life in the alley near the opium den, why does Windrider tell Moon Shadow to remember that Black Dog was once a good man?

28. computer sicence C++

Americans spell differently from Canadians. Americans write "neighbor" and "color" while Canadians write "neighbour" and "colour”. Write a program to help Americans translate to Canadian. Your program should interact with the user in the following way.

29. chemistry

peice of sodium metal reacts with water. 246ml volume of hydrogen gas was collected over water at 25 celsius and at an atmospheric pressuric pf 101.3 kpa. what was the pressure of dry hydrogen? what is the mass of sodium used up by the reaction?

30. math help!

(2-√2)/(3+√2) can you plz tell me how to solve it? plz hurry up

31. math

the 10th term is 34 of arithmetic series and the sum of the 20th term is 710.what is the 25th term?

32. CHEMISTRY.

what would be the VSEPR shape of pyridine?

33. PHYSICS

At a nuclear power plant water at 8°c from a lake is used in a heat exchanger to condense spent steam at a temperature of 120°c,to water at 85°c before it is recycled to the reactor. If the cooling water returns to the lake at a temperature of 19°c,how

34. physics

At a nuclear power plant water at 8°c from a lake is used in a heat exchanger to condense spent steam at a temperature of 120°c,to water at 85°c before it is recycled to the reactor. If the cooling water returns to the lake at a temperature of 19°c,how

35. can any smart person in c++ can answer this?

A “magic” number is an integer in which the number is equal to the sum of the cubes of its digits. Write a program to determine whether a three digit number entered by the user is a magic number.

36. math help!

48,36,27,81/4........... general term?

37. C++ programming

write a program C++ program and Use a recursive function that finds the n-th term using the following rule: tn=3tn-1+12tn-2 . please help me out!

38. Physics

A force of 2000N is used to push a box up am inclined plane that is 15m long. If the 100 kg box is raised to a height of 8m,how much work is done against friction ?let g=10m/s^2.

39. PHYSICS

1kg of fat is equal to 30MJ of energy.the efficiceny of converting fat to energy is 20%. suppose you life a mass of 12kg 2.0m vertically,500 times, how much work do you do? if all the energy used to do the work comes from the burning fat how much fat is

40. physics

At a nuclear power plant water at 8°c from a lake is used in a heat exchanger to condense spent steam at a temperature of 120°c,to water at 85°c before it is recycled to the reactor. If the cooling water returns to the lake at a temperature of 19°c,how

41. english poem

plz can anyone check my poem and mark my correct my mistakes. Lasts Forever once aparted, never met again never saw the wound heeling again once desired, beyond dreams no one i saw blessed anymore once hurtled, smashed from the roots never saw a tree

42. chemistry

what can be the source of error in titration?

43. CHEMISTRY.

what would be the VSEPR shape of pyridine?

44. Physics

what can be the source of error in lab of forces equilibrium,force board lab?

45. english poem

As fair as morn, as fresh as May, a pretty grace in saying nay, Smil'st thou sweetheart? then sing and say, Ta na na no, But O! that love enchanting eye, Lo, here my doubtful doom I try, Tell me my sweet, live I or die? She smiles, fa la la la, Ah, she

46. math

how would i find the sum of the 7 term. if i have 1st term = 11 and 7th term = 704.its a geometric series. i don't know how to find the difference?

47. math help!

the 10th term is 34 of arithmetic series and the sum of the 20th term is 710 i.e S20=710.what is the 25th term?

48. engliSH

The opposite of withdraw is? a) Shocked b) puzzled C) relieved D) revealed

49. Physics

what is the relationship between forces in equilibrium and their components?

50. PHYSICS

1kg of fat is equal to 30MJ of energy.the efficiceny of converting fat to energy is 20%. suppose you life a mass of 12kg 2.0m vertically,500 times, how much work do you do?

51. PHYSICS......

Q1.a building has three alternative routes from the ground to the first floor. i)a flight of stairs at an angle of 45 degree. ii)a near flight ladder angle 85 degree. iii)a long zig-zag slope at an angle of 15 degree. what are the disadvantages and

52. math

how to we convert one currency to another is there any formula? or plz give me an example. i have no idea how do we convert.

53. math

term given by x+2,3x-1,and 4x-1 form an arithmetic sequence. find the value of x. i didn't get it how to start this question and how it forms arithmetic sequence?

54. chemistry

What might be the major factor for leads ability to absorb x rays. Describe any practical advantages lead has for its use in x rays absorbtion.

55. chemistry

What is the allowable concentration of six organic pollutants in drinking water?

56. chemistry

What is the allowable concentration of six organic pollutants in drinking water?

57. chemistry

What are four origins of pollutants in natural water?

58. chemistry

150.0ml of iron(iii)chloride solution is mixed with 180.0ml of the sodium hydroxide solution,1.65g yield of experimental iron(iii)hydroxide is obtained.find the theoretical yeild of the precipitate. how you find that ?

59. chemistry

150.0ml of iron(iii)chloride solution is mixed with 180.0ml of the sodium hydroxide solution,1.65g yield of experimental iron(iii)hydroxide is obtained.find the theoretical yeild of the precipitate. how you find that ?

60. chemistry

1) what mass of lead(ii) acetae is required to be dissolved in a 500.0ml volumetric so that the acetate is equal to 1.48?

61. Math

y=3x^2=5x-1 how to sole it with partial factoring?

62. CHEMISTRY.

Lowering of vapor pressure is directly proportional to: a) Temperature b) Mole fraction of Solute c) Mole fraction of Solvent d) Amount of solution

63. CHEMISTRY.

Lowering of vapor pressure is directly proportional to: a) Temperature b) Mole fraction of Solute c) Mole fraction of Solvent d) Amount of solution

64. CHEMISTRY.

Lowering of vapor pressure is directly proportional to: a) Temperature b) Mole fraction of Solute c) Mole fraction of Solvent d) Amount of solution

65. PHYSICS!!!!!!!! HELP!!!!!!!

Can someone give me an example of a problem where you have to find electric field and magnetic field using an electron gun?

66. Physics

what is the relationship between forces in equilibrium and their components?

67. Physics

what is the relationship between forces in equilibrium and their components?

68. Physics

what is the relationship between forces in equilibrium and their components?

69. Computer language.

a program that prints all the numbers from 1 to 1000 that are divisible by 7. (in C++)

70. C++

a program to sort three values (from smallest to largest) entered from the keyboard. Algorithm: 1. INPUT a,b and c 2. If a greater than b If a greater than c If b greater than c The order is a, b, c Else The order is a, c, b Else . . . How will i code

71. physics

how do we find the interpolation from a graph to determin the number of images which should be observer with a mirror angle of 90 degree and how do we calculate the line equation.

72. chemistry

how can i sketch a heating curve for benzene (mp=5.5 celius and bp=80.1 celeus?

73. ms sue

triangle base is (4-x)cm and its height is (2x+3)cm.what will be the maximium area?

74. math problem. help

triangle base is (4-x)cm and its height is (2x+3)cm.what will be the maximium area?

75. math help!

how to find the points thought which the function goes like if the vertex is 2,5 and it goes through (6,-1) how would i find the other point?

76. math help!

how to find the x intercept of d(x)=9x^2-4x+7

77. math

point of symmetry? 2(x-7)(X+3) and vertex?

78. math

1/2x^2=x/4+1 how can i solve that with quadratic formula?plz i need the solution fast.

79. english

birds hidden in nests from fear of cold is this sentence correct?

80. chemistry

i have to find the ratio of naoh:mass of KHP. but i have volume oh NaOH and mass of KHP and i don't know how to find the ratio then plz help me right now.

81. math

t11=19 and t17=61.then what will be S12? arithmetic series question

82. math

1+2+3+...+100 how to find the sum of it.

83. math

1,1,2.3,5....... what can be the general term for this?

84. math

i) xy=100 ii) 9x^2+y^2=16 Are these both function or nor a function? if so then how?

85. math

y=(3/x)-1 How will i find the domain and range?

86. math

9(a+b)^2-(a-b)^2 how would you factor that?

87. English

fire and ice poem by robert frost. i have to write about how...... This poem appeals to beacause..... can someone tell me what that means actually like what should i write.

88. chemistry

Only pure substance are homologous,true or false? Can you please explain too?

89. chemistry

What is tag name for the smallest particleof covakentlg bonded ccompound?

90. chemistry

what are four examples of solution for which the concentration must be known?

91. chemistry

why do we perform tritation many times ?

92. English

how to start writing a poem?

93. chemistry

how do i find ratio of volumeHcl/volumeNaoh for my first trail of titration?

94. chemistry

if two solutions are prepared for the reaction.4.62g of Iron(iii)chloride in a 250ml columetric and for the sodium hydroxide,2.50g of solute in a 200ml volumetric flask is mixed.write two equations that describe the dissociatin of the ionic solids in water

95. maths

1 a boy was employed on the understanding that he was to receive 'p' paise for everyday he worked and 'q' paise for everyday when there was no work for him after 'd' days his total earnings amounted to rupees x how many days had he worked

96. chemistry

the mass number of an element is 18 it contains 7 electrons what is the number of protons and neutrons in it what is atomic number of an element.

97. Math

5x^2+5x-2 how to find the root?

98. chemistry

why mass of mg is determined indirectly by measuring its length instead of passing by balance?