# BOB

Most popular questions and responses by BOB
1. ## Science

1. Which type of weather technology often carries cameras that can make images of Earth's surface, clouds, and snow cover? A. weather balloon B. weather satellite**** C. computer D. automated weather station 2. Why are weather forecasts more reliable now

2. ## science

Which kind of energy transformation occurs when a skater's board falls back to the ramp?

3. ## Math

A biologist has determined that a particular osprey has a 70% chance of catching a fish on any given day. Carry out a simulation of 20 trials using the random number table below to find the probability that the osprey will actually catch a fish on all of

4. ## MATH MS.SUE HELP PLEASE!

Could somebody help me I don't understand any of this. Could someone show me or tell me how to work the problems? 1. Find the length of the hypotenuse of a right triangle with the legs of 9cm and 12cm A.8 B.21 C.15 D.225 2.The length of a hypotenuse of a

5. ## math

Why couldn't the two elephants go swimming together?

6. ## English

these lines of dialogue from the dairy of anne frank, act 1 reveal a lot about anne's character. In the paragraph , explain at least two things that you find out about anne's personality from her words. can someone start me out please im not good at essays

7. ## comprehension science

how can a cyclist minimize friction as he or she rides?

8. ## English

--The Watsons go to Birmingham- 1. Which of the following passages from the novel most accurately reflects the political climate of the United States in the early sixties? A. Let's see, where was the 'Coloreds only' bathroom downtown? B. Bright in the spot

9. ## Algebra

Participants in a study of a new medication received either medication A or a placebo. Find P(placebo and improvement). You may find it helpful to make a tree diagram of the problem on a separate piece of paper. Of all those who participated in the study,

10. ## world history

1. Which of the following would Locke most Favor? A. Republic B. Oligarchy C. Theocracy D. Absolute monarchy

11. ## Math

Find the largest $n$ so that $f(2) \cdot f(3) \cdot f(4) \cdots f(n-1) \cdot f(n) < 1.98.$

12. ## Chemistry

a) Which of the following reagents would oxidize Zn to Zn2 , but not Ag to Ag ? Answers are: Co2+ Ca2+ Br2- Br2 Co or Ca b) Which of the following reagents would oxidize Ag to Ag , but not Cl– to Cl2? Answers are: Co Br- Br2 Co2+ Ca2+ or Ca

13. ## Chemistry

Carbon dioxide gas has a solubility of 0.0972 g/100 g H2O at 40 degrees celsius. Expressed in parts per million, this concentration is closest to... (1)0.972 ppm (2)9.72 ppm (3)97.2 ppm (4)972 ppm

14. ## Calculus

for the function F(t)=ln(t^2), let f(t)=F'(t). Write the integral from a to b of f(t) dt and evaluate it with the fundamental theorem of calculus. the integral from 1 to 3 ___ dt= __

15. ## chemistry

For the following: i) H3PO4 > H3AsO4 > H3SbO4 ii) H2Te > H2Se > H2S > H2O iii) HCl > HBr > HI iv) SbH3 > AsH3 > PH3 > NH3 The order of acidity is correct for which series? 1. ) all are correct 2. ) i and ii 3. )i, ii and iv 4. ) ii, iii 5. ii, iv I know

16. ## Math ASAP

In a survey, one out of three people named blue as their favorite color. Two out of seven named red. If 1,092 people were included in the survey, how many named neither blue nor red as their favorite color? A. 416 people B. 432 people C. 540 people D. 512

17. ## health

which is a main factor that accounts for changes in the american family structure 1.casual friends 2.close friends 3.opposite sex friends 4.personal friends

18. ## Chemistry

The equilibrium constant, Kp, equals 3.40 for the isomerization reaction: cis-2-butene trans-2-butene. If a flask initially contains 0.250 atm of cis-2-butene and 0.145 atm of trans-2-butene, what is the equilibrium pressure of each gas?

19. ## Pre Calculus

Find all $2 \times 2$ matrices $\bold{A}$ that have the property that for any $2 \times 2$ matrix $\bold{B}$, $\bold{A} \bold{B} = \bold{B} \bold{A}.$

20. ## Math

2. Write a ratio for the situation in three ways comparing the first quantity to the second quantity. In union City, about one in every three homes has two cars A. 5 to 2, 5:2, 5/2 B. 1 to 3, 1:3, 1/3 C. 5 to 3, 5:3, 5/5 D. 3 to 2, 3:2, 3/2

21. ## health

which is a main factor that accounts for changes in the american family structure

22. ## Chemistry

Kc is 1.67 × 1020 at 25°C for the formation of iron(III) oxalate complex ion: Fe3+(aq) + 3 C2O42-(aq) [Fe(C2O4)3]3-(aq). If 0.0200 M Fe3+ is initially mixed with 1.00 M oxalate ion, what is the concentration of Fe3+ ion at equilibrium?

23. ## Chemistry

How do you calculate ΔSfus and ΔSvap for HCl given melting point,ΔHfus, boiling point, and ΔHvap also how do you determine the entropy change when 5.20 mol of HCl(l) freezes at atmospheric pressure.

24. ## Chemistry

40.0 ml of an acetic acid of unknown concentration is titrated with 0.100 M NaOH. After 20.0 mL of the base solution has been added, the pH in the titration flask is 5.10. What was the concentration of the original acetic acid solution? (Ka(CH3COOH) = 1.8

25. ## physics

Net force F causes mass m1 to accelerate at rate a. A net force of 3F causes mass m2 to accelerate at rate 2a. What is the ratio of mass m1 to mass m2?

26. ## Chemistry

In a particular redox reaction, MnO2 is oxidized to MnO4– and Cu2 is reduced to Cu . Complete and balance the equation for this reaction in acidic solution. Phases are optional. MnO2 + Cu^2+ ---> MnO4^- + Cu^+

27. ## chemistry

Calculate the pH and percentage protonation of the solute in an aqueous solution of 0.39 M quinine if the pKa of its conjugate acid is 8.52.

28. ## studies

Why was inflation a problem after World War II?

29. ## geometry

What is the most precise name for quadrilateral ABCD with vertices A(–3, 2), B(–1, 4), C(4, 4), and D(2, 2)? 1. parallelogram 2. rhombus 3. quadrilateral 4. rectangle

30. ## physics

In a Broadway performance, an 80 kg actor swings from a 3.75 m long cable that is horizontal when he starts.? At the bottom of his arc, he picks up his 55.0 kg costar in an inelastic collision. What maximum height do they reach after their upward swing?

31. ## Chemistry

Balance the following equation for a half reaction that occurs in basic solution. Use e– as the symbol for an electron. SO3^2- ---> S2O4^2-

32. ## Math

Find the real part of (sqrt{3} - i)^{2011}.

33. ## Math

The sum of the three smallest positive values of theta such that 4(cos*theta)(sin*theta) = 1 is k*pi. Find k. Help!!!!!

34. ## english

Identify the italicized word according to its class in structural linguistics. (There) are no easy answers.

35. ## Chemistry

A 150.0 mL sample of a 1.50 M solution of CuSO4 is mixed with a 150.0 mL sample of 3.00 M KOH in a coffee cup calorimeter. The temperature of both solutions and the calorimeter was 25.2°C before mixing and 31.3°C after mixing. The heat capacity of the

36. ## chemisty

The molar heat capacity of C6H6(ℓ) is 136 J/mol ·◦C and of C6H6(g) is 81.6 J/mol · ◦C. The molar heat of fusion for benzene is 9.92 kJ/mol and its molar heat of vaporization is 30.8 kJ/mol. The melting point of benzene is 5.5 ◦C, its boiling

37. ## science

Two stones are launched from the top of a tall building. One stone is thrown in a direction 30.0degree above the horizontal with a speed of 10.0m/s ; the other is thrown in a direction 30.0degree below the horizontal with the same speed. Which stone lands

38. ## Math

Describe a real world situation that could be represented by planes slicing a three dimensional figure to form cross sections

39. ## chemistry

Surface tension explains which of the follow- ing phenomena? I) A piece of aluminum foil floating on a lake II) A bowling ball sinking more slowly through molasses than through water III) Separating ethanol from water by distillation IV) Water beading on a

40. ## Physics

A woman on a bridge 75.0m high sees a raft floating at a constant speed on the river below. She drops a stone from rest in an attempt to hit the raft. The stone is released when the raft has 7.00m more to travel before passing under the bridge. The stone

41. ## Statistics

A car manufacturer is interested in conducting a study to estimate the mean stopping distance for a new type of brakes when used in a car that is traveling at 60 miles per hour. These new brakes will be installed on cars of the same model and the stopping

42. ## calculus

Coroners estimate time of death using the rule of thumb that a body cools about 2 degrees F during the first hour after death and about 1 degree F for each additional hour. Assuming an air temperature of 78 degrees F and a living body temperature of 98.6

43. ## Physics

Work of 730 J is done by stirring an insulated beaker containing 80 g of water. What is the change in the temperature of the water? Please show calculation

44. ## Math

ABC has vertices A(0, 6), B(4, 6), and C(1, 3). Sketch a graph of ABC and use it to find the orthocenter of ABC. Then list the steps you took to find the orthocenter, including any necessary points or slopes you had to derive.

45. ## Chemistry

If Kc = 0.143 at 25°C for this reaction, find the equilibrium concentrations of C6H12 and CH3C5H9 if the initial concentrations are 0.200 M and 0.075 M, respectively. a. [C6H12] = 0.041 M, [CH3C5H9] = 0.041 M b. [C6H12] = 0.159 M, [CH3C5H9] = 0.116 M c.

46. ## chemistry

Calculate the number of carbon atoms in 0.75 L of acetone (CH3COCH3). (density = 1.3 g/mL and boiling point = 48.5 degrees Celsius)

47. ## Economics

A monopoly firm faces a demand curve given by the following equation: P = $500 − 10Q, where Q equals quantity sold per day. Its marginal cost curve is MC =$100 per day. Assume that the firm faces no fixed cost. You may wish to arrive at the answers

49. ## Calculus

List x1, x2, x3, x4 where xi is the right endpoint of the four equal intervals used to estimate the area under the curve of f(x) between x = 3 and x = 5. 3, 3.5, 4, 4.5 3, 3.2, 4.6, 5 3.5, 4, 4.5, 5 3.25, 3.75, 4.25, 4.75 my answer was a because i kept

50. ## Math

In first gear, or low gear, an automobile's engine runs about three times as fast as the drive shaft. In second gear, the engine does not have to run as fast; usually it runs about 1.6 times faster than the drive shaft. Finally, in third, or high gear, the

51. ## main ideas

Scientists generally agree that Earth is getting warmer due to what's called the greenhouse effect. A greenhouse used for plants stays warm because sunlight and heat coming through the glass roof are mostly trapped. The heat doesn't radiate back into the

52. ## Physics

You demonstrate hitting a board in a karate class. The speed of your hand as it hits the thick board is 12 m/s with respect to the board, and the mass of your hand is about 0.74 kg. How deep does your hand go into the board before stopping if the collision

53. ## chemistry

Consider the following reaction: CaCN2 + 3H2O ¨ CaCO3 + 2NH3 105.0 g CaCN2 and 78.0 g H2O are reacted. Assuming 100% efficiency, which reactant is in excess and how much is leftover? The molar mass of CaCN2 is 80.11 g/mol. The molar mass of CaCO3 is

54. ## physics

A spaceship of mass m travels from the Earth to the Moon along a line that passes through the center of the Earth and the center of the Moon. (a) At what distance from the center of the Earth is the force due to the Earth three times the magnitude of the

67. ## health

PLEASE HELP 1. One of your friends plays video games for at least six hours each day and gets upset when he has to eat dinner with his family. This is a sign of? a. An anxiety disorder. b. A phobia c. Bipolar disorder d. An impulse-control disorder 2. A

68. ## Physics

An electron is acted upon by a force of 3.50×10−15 N due to an electric field. Find the acceleration this force produces in each case: The electron's speed is 6.00 km/s . =3.84*10^15 The electron's speed is 2.60×108 m/s and the force is parallel to the

69. ## Social Studies

If I could have some help on this question I'd appreciate it.I think the answer is B. Which problem would most likely result if banks did not exist? (1 point) People would no longer be able to save money. Money would not move through the economy very well.

70. ## chem

Ascorbic acid, H2C6H6O6, is a diprotic acide with a K1= 7.9 E-5 and a K2=1.6E-12. In a .005 M aq solution of ascorbic acid which of the following species is present in the lowest concentration. 1. H2O 2. H3O+ 3. H2C6H6O6 4. HC6H6O6- 5. C6H6O6-2

71. ## physics

In the vertical jump, an Kobe Bryant starts from a crouch and jumps upward to reach as high as possible. Even the best athletes spend little more than 1.00 s in the air (their "hang time"). Treat Kobe as a particle and let ymax be his maximum height above

72. ## statistics

A university dean wishes to estimate the average number of hours his part-time instructors teach per week. The standard deviation is 2.6 hours. How large a sample must be selected if he wants to be 95% confident of finding whether the true mean differs

73. ## physics

A 1000 kg car traveling is at 40.0 m/ s. To avoid hitting a second car the driver slams on his brakes. The brakes provide a constant friction force of 8000 N. ( a) Find the minimum distance that the brakes should be applied in order to avoid a collision

74. ## Math

When Alina was hungry she ate c cookies, which was 30% of all the cookies she had. How many cookies did she have in the beginning?

75. ## Physics

The diagram below shows a large cube of mass 25 kg being accelerated across a frictionless level floor by a horizontal force, F. A small cube of mass 4.0 kg is in contact with the front surface of the cube. The coefficient of static friction between the

76. ## pre-algebra

a bag contains 5 green marbles 2 white marbles 8 blue marbles 9 red marbles and 6 black marbles what is the probability of drawing a white marble replacing it and then drawing a green marble? Answer choices A 1/6 B 1/15 C 1/87 D 1/90 I think its D, but I

77. ## Social Studies

Identify two specific ways the Catholic Church tried to stop the spread of Protestantism

78. ## math

What set of reflections and rotations would carry rectangle ABCD onto itself? Rectangle formed by ordered pairs A at negative 4, 1, B at negative 4, 2, C at negative 1, 2, D at negative 1, 1.

79. ## Math

ABC has vertices A(0, 6), B(4, 6), and C(1, 3). Find the orthocenter of ABC?

80. ## physics

The velocity of a particle constrained to move along the x-axis as a function of time t is given by: v(t)=-(13/t_0) sin(t/t_0). a)If the particle is at x=4 m when t = 0, what is its position at t = 5t_0. You will not need the value of t_0 to solve any part

81. ## math

1. Which of the following numbers is a rational? A. 4/5 B. square root of 27 C. 4.02002000200002... D. Square root of 31 2. Which type of number is shown below? 0.313311333111... A. repeating decimal B. rational C. irrational D. terminating decimal 3.

82. ## physics

a 20 kg rock is on the edge of a 100 m cliff . the rock falls from the cliff , what is its kinetic energy just before it hits the ground ?

86. ## Chemistry

In the lab, 5.8 L of methane gas is burned with excess oxygen gas at SATP. How much carbon dioxide gas is produced? **Based on the balanced chemical equation the ratio of methane gas to carbon dioxide is 1:1, this being said, does it make sense that as 5.8

87. ## Chemistry

If you were to prepare a 1.00 molal solution of CaCl2 beginning with water at 27.0 C, what would the final temperature of the solution be (in C)? Assume that the specific heats of both pure H2O and the solution are the same, 4.18 J/K*g. The dissolution of

88. ## Chemistry

Calculate the total quantity of heat required to convert 25.0 g of liquid CCl4(l) from 25.0°C to gaseous CCl4 at 76.8°C (the normal boiling point for CCl4)? The specific heat of CCl4(l) is its heat of fusion is and its heat of vaporization is

89. ## Trig

From a point P on level ground, the angle of elevation of the top of a tower is 27°10'. From a point 23.0 meters closer to the tower and on the same line with P and the base of the tower, the angle of elevation of the top is 51°30'. Approximate the

90. ## Chemistry

Assuming all volume measurements are made at the same temperature and pressure, how many liters of carbon dioxide gas can be produced when 12.8 liters of oxygen gas react with excess carbon monoxide? Show all of the work used to solve this problem.

91. ## ap chemistry

Carbon monoxide reacts with oxygen to form carbon dioxide by the following reaction: 2CO + O2 yields 2CO2 Delta H for this reaction is -135.28 kcal. If 811.7 kcal is released, how many moles of CO must have reacted? 1). 270.5 mol 2). 40.5 mol 3). 12.0 mol

What is the rhyme scheme of "Great Glorious Gobs"? A. ABAB B. BBBA C. AABB D. AABA

93. ## Chemistry

This is for a lab about determining the equilibrium constant. Given: 5.00mL of .203M Fe(NO3)3 mixed with 100mL of .00205M KSCN in a .5M HNO3 solvent for both solutions. Resulting absorbance for solution is .315. How can i find the total Fe, [Fe*] and SCN,

94. ## physics

A 25.1 g marble moving to the right at 22.9 cm/s overtakes and collides elastically with a 12.1 g marble moving in the same direction at 11.3 cm/s. After the collision, the 12.1 g marble moves to the right at 25.1 cm/s. Find the velocity of the 25.1 g

95. ## Chemistry

Which of the following ionic compounds has the highest melting point? Help: Lattice energy Select one: a. Cs2O b. K2O c. BeO d. SrO e. LiF f. CsI

96. ## Physics!!

A cart loaded with bricks has a total mass of 25.2 kg and is pulled at constant speed by a rope. The rope is inclined at 21.6 ◦ above the horizontal and the cart moves 13.7 m on a horizontal floor. The coefficient of kinetic friction between ground and

97. ## algebra

What should you say if you see a tall wrought-iron tower in paris, france?

98. ## physics

A piece of putty of mass m = 0.75 kg and velocity v = 2.5 m/s moves on a horizontal frictionless surface. It collides with and sticks to a rod of mass M = 2 kg and length L = 0.9 m which pivots about a fixed vertical axis at the opposite end of the rod as