# Stephen

Popular questions and responses by Stephen

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?

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. ## Physics

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

4. ## 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

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. ## Maths

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

7. ## 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?

8. ## MATH

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

9. ## English

peer pressure destroys character yes or no?.

10. ## 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.)

11. ## 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

12. ## 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.

13. ## 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

14. ## 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

15. ## 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

16. ## 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

17. ## 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

18. ## ss

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

19. ## Physics

Lightning occurs when there is a ﬂow of electric charge (principally electrons) between the ground and a thundercloud. The maximum rate of charge ﬂow in a lightning bolt is about 20,000 C/s, this lasts for 100 μs or less. How much charge ﬂows

20. ## 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.

21. ## 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.

22. ## Math

AB+BA = 1A4 In the correctly worked out addition problem above, A and B represent two different digits. What digit does A represent? a 3 b 4 c 5 d 8 e 9

23. ## Chemistry

Calcium carbonate of mass 10g was heated until there was no further change A. Write an equation for the reaction B. Calculate the mass of the residue C. Calculate the volume of gas evolved at STP D. What would be the volume of the gas measured at 15°C and

24. ## Chemistry

Diamonds are measured in carats, and 1 carat=0.200g. The density of diamonds is 3.51g/cm3. what is the volume of a 5.0-carat diamond, expressed in liters?

25. ## 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

26. ## 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

27. ## 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

28. ## art

what perspectives are important in understanding a work of art?

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. ## 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?

31. ## 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

32. ## Physics

4. As shown in the figure shown below, find the total electric potential due to the two point charges A and B. +8.0 x 10-9 C A B -8.0 x 10-9 C | | | | 0.20 m 0.20 m 0.40 m

33. ## 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

34. ## Calculus

Hello, I would greatly appreciate any help that I can have with the following calculus question below. It has to do with separable differential equations. I'm also going to explain what I've done so far, so please bear with me (but honestly I don't think

35. ## math

if the three sides of an equilateral triangle are 3x + 2, 2y - X and y + 3. find X and y and the perimeter of the triangle. kindly elucidate further on this question

36. ## 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

37. ## chemistry

what will be formed when oxygen combines with hydrogen in the presence of hydrated iron 3 oxide?

38. ## Chemistry

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

39. ## Algebra

If there is a grid and you are going to draw three different rectangles so that each has an area of 12 square units and they all have different widths. What are the dimensions of the rectangle? Please help answer

40. ## 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

41. ## Science

How did the discovery of neutrons change the atomic model?

42. ## 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

43. ## math

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

44. ## chemistry

what is the result of using 75g of dihydronoxybutanedioric acid in one liter of H2O in a titration? I do not have a answer.

45. ## calculus

find the most general antiderivative of the function f(t)=8t-3sec^2t

46. ## 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

47. ## science

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

48. ## 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

49. ## 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?

50. ## 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

51. ## Physics

Two objects 18.5m apart both have the same charge. If the force on one of them is 0.4029N what is the charge (in µC) on the object?

52. ## Math

If X is partly costant and partly varies with y, when y=40, X=150, and when y=54,x=192. find x when y=73

53. ## chemistry

state two mathematical expression for Raoult's law

54. ## chemistry

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

55. ## 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?

56. ## chemistry

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

57. ## 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?

58. ## chemistry

what are the distinct characteristic does radiocarbons depends on?

59. ## 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?

60. ## Chemistry

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

61. ## chemistry

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

62. ## Maths

Solve : | x | - 5 > 6

63. ## 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?

64. ## Math

Students measure the velocity of a car as it races along a track in a clockwise direction. Their measurements are detailed below: Time (sec) | Velocity (in/sec) 0 | 4 1 | 8 2 | 10 3 | 6 4 | 9 5 | 12 6 | 5 7 | 8 8 | 10 9 | 6 10 | 12 Estimate the distance

65. ## 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?

66. ## 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

67. ## 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.

68. ## Riddle

Long_short,round_square,good_broken,painted_plaine. What are they.

69. ## math

subtract 3x-12/4x^2-8*2x^2-4/9x-36

70. ## Physics

I'm having Sig fig troubles. What would 0.98*2040 be using Sig fig rules???

71. ## math

if V(r)=4/3 pir^(3) find (v2r)/(vr)

72. ## Math

Let K(x)= (sin(3x-7)) / (e^x-2) (I'm sorry if it is not clear here, but the denominator in K(x) has the natural number, e, to the power of just x. So "x-2" is not the exponent. "x" is the exponent). The Question: Does K(x) have a horizontal asymptote? (I'm

73. ## 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

74. ## English

Just out of curiosity, is it okay to use the phrase "and so" in a sentence? Like "Johnathan knew that he had to help the boy asking a question on Jiskha. And so, he did just that, and the boy went on to being the happiest boy on earth." I just need to know

75. ## 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

76. ## CHEMISTRY

USING DOT (.) AND CROSS (x) DIAGRAM SHOW THE BONDING IN THE COMPOUND FORMED WHEN HYDROGEN AND OXYGEN COMBINE

77. ## 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 $[XYZ] =150$.

78. ## 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

79. ## Social Studies

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

89. ## Maths

A football match between United and City is watched by 24 000 spectators. Of the 24 000 spectators, 14 112 support United and 8208 support City. The rest of the spectators are neutrals who support neither team. a.Work out the percentage of the 24 000

90. ## 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

91. ## Maths

Ranee keeps £360 in a savings account for a year. At the end of the year she gets £13.50 in interest.Work out the interest rate on the account.Give your answer as a percentage. What's the answer guys and girls

92. ## Entrepeurnuership

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

93. ## entrepreneurship

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

95. ## 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?

96. ## math

What is the product written in scientific notation? (2.6 × 10–4)(2.2 × 108)

97. ## Math

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

98. ## Health

a boy notices a special needs student sitting by himself during recess. How can he get the student involved in a meaningful way? a- coach one of the teams b- be the all time referee c- the game be modified to allow for 2 goalies d- the game be played by

99. ## Science

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