JOHN

Most popular questions and responses by JOHN
1. Calculus

A stone is dropped from the upper observation deck of a tower, 200 m above the ground. (Assume g = 9.8 m/s^2.) a)Find the distance (in meters) of the stone above ground level at time t. b)With what velocity does it strike the ground? (Round your answer to

2. algebra

Cryptic Quiz 1. What do you call a skydiver with the flu? 2. How do you crash a houseboat party?

3. math

Pizzaz pg.103 Did you hear about...

4. English

1. Early in Act II of The Phantom Tollbooth, Milo meets a character named Kakafonous A. Dischord, Doctor of Dissonance. Stage directions tell you that "Two screeches and a bump are heard." The doctor's name and the stage directions are clues to the

5. science

Both carbon dioxide and water are pure substances. How are they similar to each other? A. both substances have a set ratio of atoms that cannot be separated by physical means B. both substances have a set ratio of atoms that can be separated by physical

6. Physics

Question: A Toyota car travelled at the rate of 70 km/hour leaves the house 2 hours after a Kia car has left and overtakes it in 5 hours. at what rate was Kia car travelling? What's the Formula pls? Thanks

7. english

21. identify the appropriate punctuation for the underlined word or phrase In High School, I enjoyed reading (The Catcher in the Rye)

8. Statistics

you roll two fair dice, a green one and a red one? (a) are the outcomes on the dice independent? (b)Find P(1 on green die and 2 on red die) (c)Find P(2 on green die and 1 on red die) (d)Find P(1 on green die and 2 on red die) or (2 on green die and 1 on

9. chemistry

1. Calculate the standard enthalpy change for the reaction: C2H4(g) + H2(g) → C2H6(g) given that the enthalpy of combustion for the reactants and products are: ΔHºc(C2H4)(g) = -1411 kJ mol^-1 ΔHºc(C2H6)(g) = -1560 kJ mol^-1 ΔHºc(H2)(g) = -286 kJ

10. math

A hacker is trying to guess someone's password. The hacker knows (somehow) that the password is 14 characters long, and that each character is either a lowercase letter, (a, b, c, etc), an uppercase letter (A, B, C, etc) or a numerical digit (0, 1, 2, 3,

11. calculus

If an arrow is shot upward on Mars with a speed of 52 m/s, its height in meters t seconds later is given by y = 52t − 1.86t2. (Round your answers to two decimal places.) What is the average speed over the given time intervals? (i) [1, 2] (ii) [1, 1.5]

12. Chemistry

Tarnish on iron is the compound FeO. A tarnished iron plate is placed in an aluminum pan of boiling water. When enough salt is added so that the solution conducts electricity, the tarnish disappears. Imagine that the two halves of this redox reaction were

13. math

In a family with 4 children what is the probability of having 1 boy and then 3 girls, in that order? (Exclude multiple births and assume all outcomes are equally likely). In a family with 4 children, what is the probability of having 1 boy and 3 girls, in

14. Wave

What feature is NOT defined for a wave pulse? a)period b)wave speed c)the position of a particle at a certain time d)a defined source

15. physics vectors

Consider the two vectors A with arrow = 3 i − j and B with arrow = − i − 6 j. Calculate the directions of A with arrow + B with arrow and A with arrow − B with arrow. A with arrow + B with arrow ° (counterclockwise from the +x axis) A with arrow

29. algebra

Homer is giving some cookies to each of his three brothers. To the oldest, he gives half of the cookies and half a cookie. He then gives half of what is now left and half a cookie to his second brother. Finally, he gives half of what is now left and half a

30. Data Management

How many different sums of money can be formed from one $2 bill, three$5 bills, two $10 bills, and one$20 bill? the answer at the back of the book is 23, but i don't know how to solve it.

31. Statistics

One event A is _________________ of another event B if the probabilty of event A has occurred given event B is the same as the probability that A will occur with no knowledge of B. disjoint mutually exclusive dependent independent

Lisa Richter deposited $5,000 at 4% compounded semiannually for three years. At the beginning of the fourth year, Lisa deposited$2,500. What would her balance be at the end of five years assuming she is still earning 4% compounded semiannually?

33. Calculus

Sorry this is really long. Just wondering how I would do each of these A particle is moving with velocity v(t) = t^2 – 9t + 18 with distance, s measured in meters, left or right of zero, and t measured in seconds, with t between 0 and 8 seconds

34. Chemistry

Calculate ΔG∘ at 298 K for the following reactions. Ca(s)+CO2(g)+12O2(g)→CaCO3(s) 2KClO3(s)→2KCl(s)+3O2(g) CO(g)+H2O(g)→H2(g)+CO2(g)

35. English

A: Hello. May I speak to Tom? B: Speaking. Who's calling, please? A: Hi, Tom. This is Sam. How are you doing? B: Just fine. How's your new school? A: It's great. By the way, what are you doing? B: I'm playing computer games. A: Will you come to Yunsan

36. math

Points $D$, $E$, and $F$ are the midpoints of sides $\overline{BC}$, $\overline{CA}$, and $\overline{AB}$, respectively, of $\triangle ABC$. Points $X$, $Y$, and $Z$ are the midpoints of $\overline{EF}$, $\overline{FD}$, and $\overline{DE}$, respectively.

37. college physics

Superman must stop a 190-km/h train in 180m to keep it from hitting a stalled car on the tracks. part a)If the train's mass is 3.8×10^5kg , how much force must he exert (find the magnitude)? part b)Compare to the weight of the train (give as %). partc)

38. Calculus

Which of the following integrals correctly computes the volume formed when the region bounded by the curves x^2 + y^2 = 100, x = 6, and y = 0 is rotated around the y-axis? I've narrowed it down to either pi∫(sqrt(100-y^2)-6)^2 dy or

39. English

Parenthetical expressions include information that may be helpful but are not essential to the meaning of a sentence. They are de-emphasized by ________. A. dashes B. parentheses C. commas D. brackets I'm not really understanding this question. It has to

40. chemistry

Calculate the standard cell potential for each of the electrochemical cells? 2Ag+(aq)+Pb(s)→2Ag(s)+Pb2+(aq) E∘cell......V? 2ClO2(g)+2I−(aq)→2ClO−2(aq)+I2(s) E∘cell......V? O2(g)+4H+(aq)+2Zn(s)→2H2O(l)+2Zn2+(aq) E∘cell......V?

41. Statistics

Suppose a certain species bird has an average weight of xbar 3.40 grams. Based on previous studies, we can assume that the weights of these birds have a normal distribution with sigma 0.29 grams. Find the sample size necessary for a 98% confidence level

42. Calculus

For a cylinder with a surface area of 90, what is the maximum volume that it can have? Round your answer to the nearest 4 decimal places. The volume of a cylinder is πr^2*h and the surface area is 2πrh+2πr^2.

43. physics

A nurse pushes a cart by exerting a force on the handle at a downward angle 35.0º below the horizontal. The loaded cart has a mass of 28.0 kg, and the force of friction is 60.0 N. (a) Draw a free-body diagram for the system of interest. (b) What force

44. calculus

At noon, ship A is 110 km west of ship B. Ship A is sailing east at 25 km/h and ship B is sailing north at 15 km/h. How fast is the distance between the ships changing at 4:00 PM?

45. physics

Two charges that are 2 meters apart repel each other with a force of 2 x 10-5 newton. If the distance between the charges is decreased to 1 meter, the force of repulsion will be A) 1 x 10-5 N B) 4 x 10-5 N C) 8 x 10-5 N D) 5 x 10-6 N

46. Chemistry

I've tried to solve this question multiple ways I just can't seem to get it. I just don't understand what I should be doing. An organic liquid is a mixture of methyl alcohol () and ethyl alcohol (). A 0.220- sample of the liquid is burned in an excess of

47. Calculus

A differential equation that is a function of x only a.will produce a slope field with parallel tangents along the diagonal b.will produce a slope field that does not have rows or columns of parallel tangents c.will produce a slope field with rows of

48. Physics

A police car traveling at 94.5 km/h is traveling west, chasing a motorist traveling at 77.2 km/h. (a) What is the velocity of the motorist relative to the police car? The magnitude and its direction (b) What is the velocity of the police car relative to

49. Science

Do global positioning systems use elevation on Earths system to find latitude and longitude A. By using signals from a network of satellite B. By using topographic maps C. By using satellite images D. By using photography

50. chemistry

Some distilled water is added to an empty beaker. A gram of copper(II) nitrate is added to the beaker with stirring. After a few minutes, what is in the beaker? a. solid copper(II) nitrate and water b. nitrogen gas, copper atoms, electrons, and water c. a

51. Chemistry

Which of the following metals or nonmetals are expected to displace Mn or Cl (respectively) from MnCl2? 1. Ca should displace Mn. 2. Br should displace Cl. 3. Cu should displace Mn. 4. I should displace Cl.

52. physics

Two cars leave the same point at the same time, each travelling at the same constant speed and each having the same mass. The first car drives directly east, while the second car heads directly north. If the centre of mass of the two-car system is

53. Calculus

dy/dx=x/(x-4) I.will have a slope field with negative slopes in quadrant I II.will have a slope field with positive slopes in all quadrants III.will produce a slope field with columns of parallel tangents

54. College Math

A block with a mass of m = 31 kg rests on a frictionless surface and is subject to two forces acting on it. The first force is directed in the negative x-direction with a magnitude of F1 = 11 N. The second has a magnitude of F2 = 22.75 N and acts on the

55. clemson

A farmer wants to make three identical rectangular enclosures along a straight river, as in the diagram shown below. If he has 1680 yards of fence, and if the sides along the river need no fence, what should be the dimensions of each enclosure if the total

56. Math

Which is likely to have a mass close to 2 kilograms A.a grown elephant B.a pineapple C.a 3-year old child** D.an acron

60. Pre-Calc

A hot-air balloon is floating above a straight road. To estimate their height above the ground, the balloonists simultaneously measure the angle of depression to two consecutive mileposts on the road on the same side of the balloon. The angles of

61. chemistry

Given overall reaction: P4 + 10Cl2 ---> 4PCl5 Delta H for the reaction = ? PCl5 -----> PCl3 + Cl2 Delta H = +157 kJ P4 + 6Cl2 ----> 4PCl3 Delta H = -1207 kJ Calculate the Delta H for the overall reaction.

62. math

On a 28-question test, there are 2-point questions, 4-point questions, and 5-point questions. The test is worth a total of 100 points. There are twice as many 2-point questions as 5-point questions on the test. How many 2-point questions are on the test?

63. chemistry

Treatment of gold metal with BrF3 and KF produces Br2 and KAuF4, a salt of gold. Find the mass of the gold salt that forms when a 73.0 -g mixture of equal masses of all three reactants is prepared.

64. chemistry

In a large building, oil is used in a steam boiler heating system. The combustion of 1.0 lb of oil provides 2.2×107J. Part A How many kilograms of oil are needed to heat 110 kg of water from 24 ∘C to 100∘C? (Assume that 1lb=454g, the specific heat of

65. Chemistry (URGENT)

In order to analyze the waste water containing Co^2+ from a manufacturing process, 1.0L of water was evaporated to 10.0mL, then placed in a spectrophotometer tube. The absorbance was found to be 0.20. Using your calibration curve, calculate the number of

66. Math

In a group of 40 students, 22 study Economics, 25 study Law, and 3 study neither of these subjects. Determine the probability that a randomly chosen student studies: 1. Both Economics and Law 2. At Least one of these subjects 3. Economics given that he or

67. geometry

An isosceles trapezoid has base angles equal to 45 and bases of lengths 6 and 12. Find the area of the trapezoid.

68. English expression

1. He is of medium height. 2. He is of average weight. 3. He has medium height. 4. He has average weight. 5. He has long curved hair. 6. She has short straight blond hair. 7. She has medium-length wavy blonde hair ----------------------------------- Are

69. calculus

No idea where to start The cost in dollars of producing x units of a particular camera is C(x) = x2 - 10000. (10 points) Find the average rate of change of C with respect to x when the production level is changed from x = 100 to x = 101. Include units in

write the chemical equations for the following sentences a) Aluminum reacts with oxygen to produce aluminum oxide I put Al + O2 ----------> 2Al2O3 b) Phosphoric acid, H3PO4, is produced through the reaction between tetraphosphorous decoxide and water I put

71. Chemistry

Calculate the percent ionization of 0.140 M lactic acid in a solution containing 8.5×10−3 M sodium lactate.

Experimental Procedure, Part F. A 1.0- mL volume of 0.010 M H2SO3 is added to a mixture of 12 drops of 0.01 M HIO3, 8 drops of deionized water, and 1 drop of starch solution. A color change in the reaction mixture occured in 40 seconds. a. Assuming 25

73. science

How is biodiversity related to human activities that use natural resources? A.biodiversity decreases as humans use natural resources wisely B.biodiversity decreases as humans limit there use of natural resources C.biodiversity increases as humans deplete

74. Calculus

Given the table below for selected values of f(x), use 6 trapezoids to estimate the value of x 1 3 4 6 7 9 10 f(x) 4 8 6 10 10 12 16

75. geometry

find the area of a regular hexagon with the side length 4m. round to the nearest tenth

76. Math

Let f(x) be a polynomial such that f(cos theta) = cos(4 theta) for all theta. Find f(x). (This is essentially the same as finding cos(4 theta) in terms of cos theta; we structure the problem this way so that you can answer as a polynomial. Be sure to write

77. Physics

A small disk of radius R1 is mounted coaxially with a larger disk of radius R2. The disks are securely fastened to each other and the combination is free to rotate on a fixed axle that is perpendicular to a horizontal frictionless table top. The rotational

78. Fraction

A girl spends 1/4 of her pocket money on monday and 3/8 on wednesday. What fraction of her money is left

79. Physics

A dropping ball initial at rest is dropped 1.5m; calculate a) the traveling time of the ball and b) its velocity just before reaching the ground.

80. Physics

In Figure 9-61, block 1 (mass 2.0 kg) is moving rightward at 8 m/s and block 2 (mass 4.8 kg) is moving rightward at 2.8 m/s. The surface is frictionless, and a spring with spring constant of 1180 N/m is fixed to block 2. When the blocks collide, the

81. science

How many kilograms of NH3 are needed to produce 1.00 x 10^5 kg of (NH4)2SO4?

82. english

15. Identify the sentence in which the underlined pronoun is used incorrectly. There are only six days left in the school year. It will be fun to visit their house in the summer. Their just going to have to wait to see the movie. Greg refused to go there

83. physics

How does pressure work as a restoring force to create a sound wave?

84. chemistry

name each of the following ionic compounds by stock system... couldn't find these in the list. a)NaCl b) KF c) CaS d) Co(NO3)2 e)FePO4 f)Hg2SO4 g) Hg3(PO4)2

85. Chemistry

Butane, C4H10, is a component of natural gas that is used as fuel for cigarette lighters. The balanced equation of the complete combustion of butane is 2C4H10(g)+13O2(g)→8CO2(g)+10H2O(l) At 1.00 atm and 23 ∘C, what is the volume of carbon dioxide

86. Physics

A truck driver slams on the brakes and skids to a stop through a displacement of delta x. (a) IF the truck has twice the mass, by what factor does the stopping distance change? 1) 0.25 or 2) 1 or 3) 4 (b) If the initial velocity of the truck were halved,

87. physics

racing on a flat track, a car going 32 m/s rounds a curve 56m in radius. what is the car's centripetal acceleration?

88. chemistry

A furnace that provides heat by burning methane gas must have the correct mixture of air and fuel to operate efficiently. What is the mole ratio of air to methane gas in the combustion of methane? Hint: Air is 20% oxygen.

89. stats

Suppose you toss a coin 100 times and get 82 heads and 18 tails. Based on these results, what is the probability the next flip will be a tails?

90. physics

a 2 kilogram rifle initially at rest fires a 0.002 kilogram bullet. as the bullet leaves the rifle with a velocity of 500 meters per second, what is the momentum of the rifle bullet system? isn't the answer one because final momentum minus initial momentum

91. Geography

Where can I find all the information I need regarding a specific North American State? Example: Florida...What is the State motto, flower, capital etc...

92. Trig

If sin a=0.31 cos a=0.95 sin b=0.47 and cos b=0.88 what is sin (a+b)? 0.78 -0.17 0.98 0.72

93. MUSIC

which style period would electronics have the strongest impact on? A)Classical B)Romantic C)Twentieth century D)Baroque

94. Chemistry!!!

Consider the rxn during the Haber Process: N2 + 3H2 ---> 2NH3 The equilibrium constant is 3.9 x 10^(5) at 300 K and 1.2 x 10^(-1) at 500 K. Find Delta H reaction and Delta S for reaction

95. Math

Why doesn't Gyro on Even Numbers When Playing Roulette?

96. world history

What were the outcomes of King Henry VIII breaking away from Rome and forming the Church of England? (Select all that apply.) King Henry VIII became both the monarch of England and the head of the church. King Henry VIII ordered that Catholic monasteries

97. Physics

The main water line enters a house on the first floor. The line has a gauge pressure of 1.70 105 Pa. (a) A faucet on the second floor, 6.5 m above the first floor, is turned off. What is the gauge pressure at this faucet? (b) How high could a faucet be

98. CHEMISTRY

A Sample of gas originally at 25 degrees C and 1 atm pressure in a 2.5 L container is allowed to expand until the pressure is .85 atm and the temperature is 15 degrees C. What is the final volume of gas? Did anyone get 2.6 L