# stephen

Most popular questions and responses by stephen
1. ## math

For the Rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. For an 10 month period, the last term is and the series sum is . For a 15 month period, the last term is and the series sum is . For a 20 month

2. ## Math 117

A class has 10 boys and 12 girls. In how many ways can a committee of four be selected if the committee can have at most two girls?

3. ## AP Chemistry help!!!!!

How does the boiling point of ethane (CH3CH3) compare with that of ethanol (CH3CH2OH)? 1. The boiling point of ethane is higher because it has stronger London dispersion forces. 2. The boiling point of ethane is higher because it has stronger dipole-dipole

4. ## chem

What mass of hydrochloric acid (in grams) can be neutralized by 2.3g of sodium bicarbonate? (: Begin by writing a balanced equation for the reaction between aqueous sodium bicarbonate and aqueous hydrochloric acid.)

5. ## physics

a ball of mass 0.1kg is thrown vertically upwards with an initial velocity of 80m/s.calculate the potential energy (I) half way up (ii) at its maximum height.what is the kinetic energy as it leaves the ground

6. ## ss

In what ways can it be argued that the European union caused ww1 and ww2

7. ## art

what perspectives are important in understanding a work of art?

8. ## AP Calculus AB

The fence around Wayne Manor (a rectangular plot of land) is going to be replaced. No fence will be required for the side lying along Gotham river. If the new wrought iron fence costs $12 per meter for the side parallel to the river and$4 per meter for

9. ## Maths

Change these fractions to twentieths and then arrange them in order of size, smallest first. 7/20 2/5 3/4 7/10

10. ## Science

At which point is more silt in the water in the mountains or on flatland why

11. ## physics

A block of mass M hangs from a rubber cord. The block is supported so that the cord is not stretched. The unstretched length of the cord is L0 and its mass is m, much less than M. The "spring constant" for the cord is k. The block is released and stops at

12. ## English

Is the word "and" still considered a coordinating conjunction if it is being used in a list rather than to connect two independent clauses? For example: "Jeff wants to buy an apple, a pear, and a banana" Is the "and" used in that sentence still a

13. ## chemistry

When 15.3g of NaNO3 was dissolved in water inside a constant pressure calorimeter, the temperature fell from 25.00 °C to 21.56 °C. If the heat capacity of the calorimeter (including the water it contains) is 1071 J/°C, What is the enthalpy change for

14. ## Math HELP

The table below shows the measured dimensions of a prism, and the maximum and minimum possible values based on the greatest possible error. Dimensions l w h Measured 9 5 3 Maximum 9.5 5.5 3.5 Minimum 8.5 4.5 2.5 a. Find the measured volume. b. Find the

15. ## MATH

CONSTRUCT TRIANGLEABC AB=7CM ,AC=9.5 AND B=120 MEASURE BC

16. ## Entrepeurnuership

which of the following companies is the easiest type to set up sole proprietorship LLC C corporation S corporation

17. ## Chemistry

Given Lead (||) oxide, nitric (V), sodium carbonate solution and water. Explain briefly how you can prepare Lead (||) Carbonate. Use equation where possible.

18. ## Math

1. The curve y=10/2x+1 -2 intersects the x-axis at A. The tangent to the curve at A intersects the y-axis at C. (i) Show that the equation of AC is 5y+4x=8 (ii) Find the distance of AC 2. The equation of a curve is y=1/6(2x-3)^3-4x (i) Find dy/dx (ii) Find

19. ## Calculus

The Question: A particle moves along the X-axis so that at time t > or equal to 0 its position is given by x(t) = cos(√t). What is the velocity of the particle at the first instance the particle is at the origin? So far I was able to determine that the

20. ## phy

a watermelon seed has the following coordinates: x= -5.0, y = 8.0m, and z = 0m. find its position vector (a) in unit-vector notation and as (b) a magnitude and (c) an angle relative to the positive direction of the x axis (d) sketch the vector on the

21. ## chemistry

state two mathematical expression for Raoult's law

22. ## Chemistry

how many molecules of N2 could fit in a 2.00L soda bottle at 23C and 755mmHg

23. ## chemistry

an arcaecologist recovered wood with a specific activity of 8.61d/min.g, assume the ratio of 12C/14C in a living plant has the activity of 15.3d/min.g estimate the age of the wood?

24. ## Math 1

The number 2 is chosen to begin a ladder diagram to find the prime factorization of 66. What other numbers could have been used to start the ladder diagram for 66? How does starting with a different number change the diagram?

Altitudes $\overline{XD}$ and $\overline{YE}$ of acute triangle $\triangle XYZ$ intersect at point $H$. If the altitudes intersect at a $123^\circ$ angle, and $\angle YXH = 26^\circ$, then what is $\angle HZX$ in degrees?

26. ## ap chemistry

Arrange the following 0.10 M solutions in order of increasing H+ : HClO4 , H2SO4, NH4Br , KCN, KBr, KOH

27. ## Physics

A plane wave has an equation y=25 sin(120t - 4x), find wavelength in meters,frequency,period,velocity and amplitude.

28. ## chemistry

state the equation for the determination of molecular mass using (i)osmotic pressure (ii)depression of freezing

29. ## Programming

I need help with debug Debug06-02 // Program lets user input scores on four tests // Average is computed and letter grade is determined // Letter grades are based on 90 for an A, 80 for a B, and so on start string name num score num NUM_TESTS = 4 num

30. ## math probability

A fair tetrahedral die (with face 1,2,3 and 4)and a fair coin are tosses together Construct a table of sample space of a random experiment Use your sample space to.find the probability that (1):a tail and an odd number show up (2):a head and a square show

31. ## chemistry

C2H6 + O2 -> CO2 + H2O How many g of carbon dioxide are produced at the same time as 360g of water vapor in the burning of ethane

32. ## Social Studies

Why did the Spanish and French start fighting? Question from Social Studies weekly week 8 for 4th graders.

33. ## English

peer pressure destroys character yes or no?.

34. ## Math

Context: The function v(t) represents the velocity of a particle moving along a horizontal line at any time, t, greater than or equal to zero. If the velocity is positive, the particle moves to the right. If the velocity is negative, the particle is moving

35. ## chemistry

the label of a bottle of NaOH bears the following of 46.7% and density of 1.57gml calculate the molar concentration of it?

36. ## Physic

A Uniform beam 6.0 metre long and weighing 4kg rest on supports at p and q placed left and right 1.0 metre from each end of the beam. Weights of mass 10kg and 8kg are placed near p and q respectively one each end of the beam. Calculate the reactions at p

37. ## algebra

Forest ranger measure depth of 82 inches of snow on a mountain peak at 8am. Snow is expected to fall at a steady rate of 3/4 inch per hour. write an equation that approximates the depth "y" of snow on the mountain peak "x" hours after 8am.

38. ## AP Chem help?!!!!

What effect will dissolving larger amounts of salt in a beaker of water have on the concentration and conductivity of the solution? 1. The concentration does not change, but the conductivity increases. 2. Both concentration and conductivity decrease. 3.

39. ## Geometry

Point $G$ is the midpoint of median $\overline{XM}$ of $\triangle XYZ$. Point $H$ is the midpoint of $\overline{XY}$, and point $T$ is the intersection of $\overline{HM}$ and $\overline{YG}$. Find the area of $\triangle MTG$ if $[XYZ] =150$.

40. ## ap physics

A 650N man jumps out of a window into a fire net 8m below. The net stretches 1.5m before bringing the man to rest and tossing him back into the air. What is the maximum potential energy of the net compared to its unstretched potential energy?

41. ## math

suppose you are drinking root beer from a conical cup. the cup has a diameter of 8 cm and a depth of 10 cm. as you suck the straw, root beer leaves the cup at the rate of 7 cm^3/second. at what rate is the level of the liquid in the cup changng when the

42. ## Trigonometry

The expression log(x^n/ radical y)is equivalent to 1. n log x - 1/2 log y 2. n log x- 2 log y 3. log (nx) - log (1/2y) 4. log (nx) - log (2y)

43. ## chemistry

when a quantity of powdered sulphur is burnt in excess oxygen, 100cm3 of SO2 were produced at STP CAL,the vol of gas at STD

44. ## chemistry

what are the distinct characteristic does radiocarbons depends on?

Pain says she should get $3 discount on the price of each shirt and a$3 discount on the price of each pair of jeans. Part 1 Write and simplify an expression to find the amount she would pay if this is true. Part 2 why are the amounts Pani pays in a and b

46. ## Math

Shows an equilateral triangle with the length of its sides given in terms of a and b.4a cm and 3b cm.(a+b+c)cm.

47. ## math 121

Henry will reject a cookie with less than 8 raisins.In the past, one out of every 100 cookies had less than 8 raisins. Find theprobability that the first cookie Henry rejects is the 5th cookie on the line.

48. ## chemistry

what volume (in litres) of 17.6M NaOH will be used to prepare 0.5M NaOH in 50,000ml?

49. ## chemistry

given that 5milimeter of 5.2mol per liter NaCl will be used to prepare 0.026mol per liter NaCl, describe how you will prepare this solution?

50. ## science

How many drop (1drop=0.05ml) of 0.20M potassium iodide must we add to 0.010M Pb(NO3)2 to get precipitation of lead iodide to start if Ksp of lead iodide is 7.1x10^-9.

51. ## Chemisty

In an experiment, 23.0 g of ice at –25°C is converted into steam with a temperature of 124°C. How much heat is required for the process? The following data may be of use: vap = 2260 J/g; Hfus = 334 J/g; Cp(ice) = 2.06 J/g • °C; Cp(water) =

52. ## Physics

Three point charges are placed on the x-y plane as follows: Q1=-1.2nC at ( 3,4)cm, Q2=2.3nC at (0,0)cm and Q3=-3.7nC at (5,0)cm. What is the net force exerted by the two point charges on Q2?

53. ## Physical Science 9

what part of the carbon process is responsible for the release of carbon at a p[power plant combustion photosynthesis digestion decomposition my answer is a combustion

54. ## Physics

A ball of mass 0.3kg, moving at a velocity of 20ms-1 is suddenly hit by a force of 5N for a time of 0.03 sec. find its new velocity

55. ## science

how does(what is the chemistry involved) k2so4 raise the boiling point of h2so4

56. ## Chemistry

Given the enthalpies of formation for the following substances, determine ƒ´Hrxn for Cl2(g) + C2H2Cl2(g) „_ C2H2Cl4(g) Substance ƒ´H (kJ/mol) Cl2 0 C2H2Cl2 4.27 C2H2Cl4 ¡V155.6

57. ## trigonometry

Use a sum-to-product formula to rewrite cos5w+cos2w as a product.

58. ## Math

A hiker started to climb up the hill at 6:00 am and either kept climbing up or rested at some place(s). He reached the top at 6:00 pm. he rested there for the next 12 hours. Next day at 6:00 am, he began to travel down the same path. He either moved

59. ## math

The roof of a tunnel is in the shape of a parabolic arch whose highest point is 18m above the road. The road surface is 16m wide. Lights are placed in the tunnel 12 meters high. How far from center of the tunnel are the lights placed?

60. ## Chemistry

Three gases (8.00 of methane, , 18.0 of ethane, , and an unknown amount of propane, ) were added to the same 10.0- container. At 23.0 , the total pressure in the container is 3.90 . Calculate the partial pressure of each gas in the container.

61. ## Chemisty

In an experiment, 230 kJ of heat energy are released to the surroundings when steam is converted to liquid water. Calculate the number of grams of water condensed. The following data may be of use: vap = 2260 J/g; Hfus = 334 J/g; Cp(ice) = 2.06

62. ## Physics

A sphere of radius r =5cm and volume charge density ρ=14μC/m^3 spins at ω=200rad/s . What is the magnetic field at the center of the sphere in Tesla?

63. ## Math

The question goes as follows: Two trains are moving toward each other at speeds 17 mph and 43 mph. How far apart are they 1 minute before they pass each other? So I have been trying to answer this question for a while now, and it is turning out to be a

64. ## Science

How did the discovery of neutrons change the atomic model?

65. ## math

what is the volume of a rectangular prism l=7in.w=5in.h=3in.

66. ## Geometry

a parallelogram has the vertices (0,3), (3,0), (o,-3), and (-3,0). determine what type of parallelogram and find the perimeter and area

67. ## Chemistry

Given the reaction shown below, calculate: (a) The amount of NO2, in grams, generated from reactants if 300.23 kJ of heat energy is released during the course of the reacton. (b) The heat energy released if 33.23 grams of O2 is consumed in the reaction. 2

68. ## math

How do you find the definite integral of an absolute function? ∫_0^3|2x-3| lower limit= 0 upper limit = 3

69. ## Math

Solve using the annihilator method Y"-8y'+20y=5xe^(4x) sin (2x)

70. ## math

what is the volume of a rectangular prism l=7in.w=5in.h=3in.

71. ## math

A baseball player hits a line drive to center field. As he rounds second base, he heads directly for third, running at 20 ft/sec. How fast is the distance from the rnner to home plate changing when he is halfway to third base?

72. ## math

Bacteria are growing in a circular colony one bacterium thick. the bacteria are growing at a constant rate, making the area of the colony increase at a rate of 12mm^2 per hour. How fast is the radius changing when the radius is 3mm?

73. ## Microeconomics

In a patent-driven market, using the concept of minimum efficient scale of production, explain what would happen to competiton and to price when the patent expires? I don't see how I can interweave the minimum efficient scale of production into this

74. ## physics

during 4.0 min a 5.0 a current is set up in a wire,how many coulombs and the electrons pass through any cross section across the wire?

75. ## Chemisty

How much heat energy is released to surrounding when 15.0 g of water at 35°C is converted into ice with a temperature of -45°C? vap = 2260 J/g; Hfus = 334 J/g; Cp(ice) = 2.06 J/g • °C; Cp(water) = 4.18 J/g • °C; Cp(steam) = 1.99 J/g •

76. ## Math

At the school store Juanita bought two books and a backpack for a total of $26 before tax. Each book cost less than$8. Find each price.

77. ## mathematics

A mortgage is taken out of 100000 dollars and is repaid by annual instalments of 20000 dollars. Interest is charged on the outstanding debt at 10 percent annually. If the first repayment is made one year after the mortgage is taken out, find the number of

78. ## chemistry

25mL of tartaric acid solution is titrated against 31mL of NH4OH. What is the normality of the NH4OH? Please explain how to work this problem.

79. ## Maths

A perfectly cylindrical container standing upright with a top and bottom(an oil drum or coke can for example) of area A has an empty mass of M and a height of H. It is filled with a liquid of uniform density(p)up to the height of h. When the container is

80. ## math

what is the GCF of 300 and 225 using prime factorization

81. ## chemistry

How can precipitates be dissolved? never? by adding constituent ions to the solution? by complexing one of the constituent ions in a soluble form?

82. ## Chemistry

What will be the final temperature of a 22.0 g piece of iron (Cp = 25.09 J/K • mol), initially at 25°C, if it is supplied with 28.2 J from a stove?

83. ## chemistry

For the following: a)give the reaction type; b)complete and balance the reaction; c)using your answer to part b, determine how much of the other reactant is needed, and how much of each product will be formed, for the given starting amount (below); and d)

84. ## chemistry

What will happen if ammonium chloride solution is used to standardize the potassium tetraoxomangate(vii)solution?

85. ## Maths

In a sale of electrical equipment, the price of all goods is reduced by . Work out the sale price of the following. a A DVD player which normally costs £88 b A portable audio player which normally costs £150 c A laptop computer which normally costs £986

86. ## Science

What type of a bond is a metal cation likely to form?

87. ## trigonometry

How do i do them? :l 7. At 2:00 P.M., the angle between the hour and minute hands on a clock is 60° (approximately 1.05 radians). The arc length formed by the two hands is 2.63 inches. What is the radius of the clock in inches? (Round to the nearest

88. ## College Physics

14) Given the following vectors, find the magnitude and direction: • A = 47 m and the angle is 0° • B = 62 m and the angle is 35° This is relative to the x-axis Magnitude: 401 m 140 m 104 m 0 m 503 m Direction: 20° 45° 55° 220° 90°

89. ## chemistry

25 milliliters of tartaric acid solution is titrated against 31 milliliters of NH4OH. What is the normality of the NH4OH?

90. ## chemistry

calculate the number of liters of liquid ethanol (density = 0.789g/ml) required to obtain a sample containing 1.00*10^25 C2H5OH molecules

91. ## design/art

what is the principle of elaboration in design? i have seen it listed with variety and contast.

92. ## Chemistry

Given Zn(NO3)2 + (NH4)2S = ZnS + 2NH4NO3 (molar mass of Zn(NO3)2 189 g, molar mass of (NH4)2S 68 g), what is the molarity of a 250 ml solution if you have 123 g of zinc nitrate?

93. ## chemistry

I have been knocking around this question for what seems to be an eternity. We have not gotten that far in this class so this is for extra credit. I have managed to get myself confused about something that should be easy. 25mLof tartaric acid solution is

94. ## translat english to french

what ido after school when i close from school i eat my snack and itake my bath for the afternoon then i rest for some thirty minutes atfer taking my short rest i join my mother in the kitchen toprepare dinner on days that i do nothave private studies but

95. ## math

I am a number between 0.23 and 0.31. I have 3 digits. All of my numbers are the same. What number am I?

96. ## Physics

A flowerpot falls from a window sill 37.6 m above the sidewalk.? A) What is the velocity of the flowerpot when it strikes the ground? The acceleration of gravity is 9.81 m/s2 ? B) How much time does a passerby on the side-walk below have to move out of the

97. ## Physics

A 70 kg man carrying a 10 kg suit case climbing a ladder of 5 m in two minute, power developed by the man is (g=10 m/s2 ).?

98. ## Maths calculus

A rectangular box has a square cross-section and the sum of its length and the perimeter of this cross-section is 2 m. If the length of the box is x m, show that its volume V m^3 is given by V = [x(2-x)^2]/16. Hence find the maximum volume of the box.

Helping my child study. Are there any online guides that can help me teach how to predict the products of a reaction. i.e. _ Ag(NO3)+ _ CaCl2 yields Really want to be able to teach my child how to do this rather than have the answer. Thanks