# john

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. ## 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

3. ## 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

4. ## 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]

5. ## 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

6. ## math

Pizzaz pg.103 Did you hear about...

7. ## 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

8. ## 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

9. ## Physics

A box is given a push so that it slides across the floor. How far will it go, given that the coefficient of kinetic friction is 0.24 and the push imparts an initial speed of 3.8 m/s?

10. ## 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

11. ## algebra

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

12. ## 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

13. ## 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,

14. ## Pre-Calc Helppp!!!

Use the Law of Sines to solve for all possible triangles that satisfy the given conditions. (If an answer does not exist, enter DNE. Round your answers to one decimal place. Below, enter your answers so that B1 is smaller than B2.) a = 39, c = 40, angle A

15. ## CHEMISTRY

A mixture of Xe, Kr, and Ar has a total pressure of 6.7 atm. What is the mole fraction of Kr if the partial pressures of XE and Ar are 1.6 atm and 2.8 atm? Did anyone get .343 ?

16. ## Physics

You toss a tennis ball straight upward. At the moment it leaves your hand it is at a height of 1.5 m above the ground, and it is moving at a speed of 8.0 m/s. (a) How much time does it take for the tennis ball to reach its maximum height? (b) What is the

17. ## science

A chair of mass 15.5 is sitting on the horizontal floor; the floor is not frictionless. You push on the chair with a force = 38.0 that is directed at an angle of 42.0 below the horizontal and the chair slides along the floor.Use Newton's laws to calculate

18. ## Calculus

A spinner is used for which it is equally probable that the pointer will land on any one of six regions. Three of the regions are colored red , two are colored green, and one in colored yellow. If the pointer is spun twice, find the probability it will

19. ## english

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

20. ## 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)

21. ## physics

If a car rolls gently(vo=0) off a vertical cliff, how long does it take to reach 85km/h?

22. ## 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

23. ## 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

24. ## Physics

In uniform circular motion, which of the following quantities are constant: speed, instantaneous velocity, tangential velocity, radial acceleration, tangential acceleration? Which of these quantities are zero throughout the motion?

25. ## Chemistry

In a gas mixture of He, Ne, and Ar with a total pressure of 8.40 atm, the mole fraction of Ar is ________ if the partial pressures of He and Ne are 1.50 and 2.00 atm respectively. pHe = 1.50 atm. pNe = 2.00 atm. pAr = 8.40 atm - 1.50 - 2.00 = ?? mole

26. ## Science

What is the goal of technology A.to understand the natural world B.to improve how devices operate C.to improve how people live D.to understand how systems operate My answer A

31. ## 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

32. ## Physics

Bethany, who weighs 420N, lies in a hammock suspended by two ropes tied to two trees. The left rope makes an angle of 45 degrees with the ground, the right one makes an angle of 30 degrees. Find the tension of the left rope. Find the tension of the right

33. ## 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

34. ## 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

35. ## math

Every cereal box has a gift inside, but you cannot tell from the outside what the gift is. The store manager assures you that 16 of the 58 boxes on the shelf have the secret decoder ring. The other 42 boxes on the shelf have a different gift inside. If you

36. ## chemistry

what is the mass in grams? a) 3.011 x 10^23 atoms F b)1.50 x 10^23 atoms Mg c)4.50 x 10^12 atoms Cl d)8.42 x 10^18 atoms Br e) 25 atoms w f) 1 atom Au can you please explain a and b to me then i'll come back later and see if i did the rest right? Thanks in

37. ## 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

38. ## 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.

39. ## 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

40. ## atlantic high

Why Was Professor CLabberhead Utterbunk Holding Up a Piece of Bread ?

41. ## math

A confectioner has 300 pounds of a chocolate that is 1 part cocoa butter to 7 parts caramel. How much chocolate that is 1 part cocoa butter to 15 parts caramel should be combined with the first in order to create a new chocolate that is 1 part cocoa butter

42. ## 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

43. ## Econ

Suppose the government wants to reduce the total pollution emitted by three firms in its area. Currently, each firm is creating 4 units of pollution in the area, for a total of 12 pollution units. The government wants to reduce total pollution in the area

44. ## english

25. which sentence is punctuated correctly? a. "Are you finished yet, Miriam asked?" b. Are you finished yet, " Miriam asked?" c. "Are you finished yet"?Miriam asked. d. "Are you finished yet?" Miriam asked.*** 26. Which sentence correctly uses punctuation

45. ## 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

46. ## physics

if two forces 10N and 20N are inclined at angle 60degree to each other. Find the resultant force.

47. ## 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?

48. ## physics

A pelican flying along a horizontal path drops a fish from a height of 5.4m. The fish travels 8.0 m horizontally before it hits the water below. What was the pelican's speed?

49. ## Science

A group of parts that work together is called. A. Technology B. Process. C. System. D. Feedback I think its C?

50. ## 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

82. ## Fraction

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

83. ## Math

(8.86 + 1.0 * 10^-3) / (3.610 * 10^-3) Calculate the above formula, expressing the answer in scientific notation with the correct number of significant figures: 8.86 + 1.0 * 10^-3 = 8.86 + 0.0010 = 8.8610 = 8.86. 8.86/(3.610 * 10^-3) = 2454 2.454 * 10^3

84. ## 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

85. ## algebra

in a relationship between variables, what is the variable called that changes in response to another variable? a. function b. input function c. independent variable d. dependent variable

86. ## 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

87. ## another question algebra

write an explicit formula for the sequence 7,2,-3,-8,-13 then find a14

88. ## Chemistry

Explain the production of an emission spectrum in terms of the energy states of an electron. what does that mean someone help me please.

89. ## physics

As a protest against the umpire’s calls, a baseball pitcher throws a ball straight up into the air at a speed of 20.4 m/s. In the process, he moves his hand through a distance of 1.57 m. The acceleration of gravity is 9.8 m/s 2 . If the ball has a mass

90. ## 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.

91. ## 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?

92. ## Physics

A light beam strikes a piece of glass at a 60.00° incident angle. The beam contains two wavelengths, 450.0 nm and 700.1 nm, for which the index of refraction of the glass is 1.4824 and 1.4750, respectively. What is the angle between the two refracted

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

94. ## 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

95. ## chemistry h/w help

The concentration of lead nitrate (Pb(NO3 )2 ) in a 0.726 M solution is __________ molal. The density of the solution is 1.202 g/mL.

96. ## Chemistry

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

97. ## Chemistry

If a copper sample containing some zinc impurity is to be purified by electrolysis, the anode and the cathode must be which of the following? a. anode: pure copper cathode: pure zinc b. anode: pure zinc cathode: pure copper c. anode: pure copper cathode:

98. ## Chemistry

Naphthalene combustion can be used to calibrate the heat capacity of a bomb calorimeter. The heat of combustion of naphthalene is -40.1 kJ/g. When 0.8210 g of naphthalene was burned in a calorimeter containing 1,000. g of water, a temperature rise of