Popular questions and responses by adam
1. ## chemistry

What is the molarity of a saline solution that contains 0.900 g NaCl (58.44 g/mol) dissolved in 100.0 ml of a solution?

2. ## math

Al is twice as old as Bill, who is twice as old as Carl. In 10 years, Al will be twice as old as Carl. How old is Al now? A. 40 B. 20 C. 10 D. 5

3. ## Trigonometry

Verify whether this is an identity: ((sec^2(x))(sec^2(x)+1))/sin^2(x) + csc^4(x) - tan^2(x)*cos^2(x) = (sec^4(x))/sin^2(x) + sec^2(x)*csc^4(x) - sin^2(x)

4. ## math

By your cell phone contract, you pay a monthly fee plus some money for each minute you use the phone during the month. In one month, you spent 200 minutes on the phone, and paid \$22.45. In another month, you spent 350 minutes on the phone, and paid \$29.65.

5. ## Physics (As Level) 12 Grade

2) An aircraft lands on a runway at a speed of 40 meters per second (ms^-1) and brakes to a halt in a distance of 860m. Calculate a) The Braking time. B) The deceleration of the aircraft.

6. ## math

If a bicycle wheel has traveled f/π feet after n complete revolutions, what is the length in feet of the diameter of the bicycle wheel? A. f/nπ^2 B. π^2/fn C. nf/π^2 D. nf/π^2 E. f/n

7. ## Algebra

Solve. (7+u)(3u-1)=0 (If there is more than one solution, separate them with commas.)

8. ## math

china population is 1.33 billion and continues to grow at the same rate,how many years until the population reaches 1.5 billion people?

9. ## CALC

Use Newton's method to approximate a root of the equation x3+x+3=0 as follows. Let x1=–1 be the initial approximation. The second approximation x2 is _____? and the third approximation x3 is _____?

10. ## chemistry

In which anion do you expect a shorter O-O distance? BaO2 or KO2

11. ## power dissipation

What is the power dissipated by resistor R1 of the following circuit: two batteries in series (with values V1 = 20 volts and V2 = 20 volts) connected across three resistors in series with values R1 = 10k, R2 = 10k, and R3 = 20k im getting the answer 4 but

12. ## math

A low land, 48m long and 31.5 m broad is raised to 6.5 dm. For this, earth is removed from a cuboidal hole, 27 m long and 18.2 m broad, dug by the side of the land. The depth of the hole will be? A man rows 12 km in 5 hrs against the stream, the speed of

13. ## math

The value of 4x^3-x/(2x+1)(6x-3) when x=9999 If 7 men working 7 hrs a day for each of 7 days produce 7 units of work, then the units of work produced by 5 men working 5 hrs a day for each of 5 days is? Pls help***

14. ## English

Which of the following is an example of a narrative poem? A. The Bridegroom by Alexander Pushkin B. The Fish by Elizabeth Bishop C. Danny Deever by Rudyard Kipling D. All of the above

15. ## Math

Suppose that the height (in centimeters) of a candle is a linear function of the amount of time (in hours) it has been burning. After 11 hours of burning, a candle has a height of 18.6 centimeters. After 27 hours of burning, its height is 12.2 centimeters.

16. ## college physics

A popular daredevil trick is to complete a vertical loop on a motorcycle. This trick is dangerous, however, because if the motorcycle does not travel with enough speed, the rider falls off the track before reaching the top of the loop. What is the minimum

17. ## Finance

A firm has forecasted sales of \$3,000 in April, \$4,500 in May and \$6,500 in June. All sales are on credit. 30% is collected the month of sale and the remainder the following month. What will be the balance in accounts receivable at the beginning of July

18. ## Chemistry terms

Match the terms with the correct definitions. 1. ligand 2. coordination compound 3. Lewis base 4. complex ion 5. bidentate ligand 6. octahedral complex a) a ligand that can form two bonds (donate two electron pairs) to a metal ion. b) a neutral compound

19. ## Math

A bowl has red,green and blue marbles.There are 95 red marbles.the nuber of blue marbles is 5 timesthe number of green mables altogether red and green marbles are 189 less then blue marbles .how may marbles are there in total

1. The UV index on a sunny day can be modelled by the function y= -0.15(x-13)^2+7.6 , where x represents the time of day on a 24-h clock and f(x) represents the UV index. At what time(s) was the UV index 7? 2. Determine if each system has one, two, or no

Mrs. Scott decided that she would spend no more than \$120 to buy a jacket and a skirt.f the price of the jacket was \$20 more than 3 times the price of the skirt, find the highest possible price of the skirt. How to set up this

22. ## Chemistry

Could someone help me with these problems; A)If 5.97mL of a solution of NaCl contains 2.54g of sodium ion, what is the molarity of the sodium chloride solution? -I know M=#moles solute/L but when I do this I get 7.28*10^-3 which is wrong, the answer should

Elemental mercury was first discovered when a mercury oxide was decomposed with heat, forming mercury metal and oxygen gas. When a 0.204-g sample of the mercury oxide is heated, 0.189 g of mercury metal remains. a)what is mole ratio of mercury to oxygen in

24. ## math

A vendor bought 10 dozen eggs at the rate of Rs 22 per dozen. Six of the eggs were rotten. He sold the remaining eggs at the rate of Rs 2.50 per egg. Find his profit or loss. Ans-65 profit Pls help me

25. ## electronics

At the critical frequency, the output of a filter is down from its maximum by

26. ## physics

How far would you have to drill into the Earth, to reach a point where your weight is reduced by 8.0 ? Approximate the Earth as a uniform sphere.

27. ## Language Arts

wet with dew straggly branches slapped and scratched at my legs and hid uneven ground so that several times tumbling and sliding downward which type of conflict best characterizes the event in the passage? a character vs self b character vs nature c

28. ## Physics

A barbell is mounted on a nearly frictionless axle through its center. The low-mass rod has a length d = 0.27 m, and each ball has a mass m = 0.2 kg. At this instant, there are two forces of equal magnitude F applied to the system as shown in the figure,

29. ## Math

What is the value of the digit 8 in the number of 56,782,010,00

30. ## Chemistry

a) A sprinter must average 24.0 mi/h to win a 100-m dash in 9.30 s. What is his wavelength at this speed if his mass is 84.5 kg? b) For potassium metal, the work function W (the minimum energy needed to eject an electron from the metal surface) is 3.68 ×

31. ## Physics

The two strands of the helix-shaped DNA molecule are held together by electrostatic forces as shown in the Figure 16-44 in the textbook. Assume that the net average charge (due to electron sharing) indicated on H and N atoms is 0.2e and on the indicated C

32. ## Physics

A proton is at the origin and an electron is at the point x = 0.37 nm, y = 0.39 nm Find the electric force on the proton? I don't even know where to start. Can someone help me?

33. ## Calculus

An object's velocity after t seconds is v(t)= 38-2t feet per second. a. How many seconds does it take for the object to come to a stop (velocity = 0)? b. How far does the car travel during that time? c. How many seconds does it take the car to travel half

34. ## math

A sum is invested at compound interest payable annually. The interest in two successive years was Rs 900 and Rs 981. Find the sum. If the sum of all internal angles and sum of all external angles of a regular polygon are equal, then the number of sides of

35. ## circuits

If a series RLC circuit has R = 25 ohm, XL = 50 ohms, and XC = 30 ohms, what will be the total impedance?

36. ## CHM

Some of the cyclohexane solvent vaporized during the temperature versus time measurement. Will this loss of cyclohexane result in its freezing point being recorded as too high, too low or unaffected? Explain. Please someone explain this to me I don't

37. ## Chemistry

An aqueous KNO3 solution is made using 72.5 grams of KNO3 diluted to a total solution volume of 2.00 liters. If the molarity of the solution is .359 M and the molality of the solution is .354, what is the mass percent of the solution?

38. ## calc 1

Evaluate the indefinite integral. e^(8x)sin(e^(8x))

39. ## Algebra 2

Suppose you did a survey of male shoes size and the mean of that survey was size 10 with a standard deviation of 1.5. What is the z-score of a size of 7.5?

40. ## Organic chem

Classify each as a lewis acid or lewis base... A)H20 B)O2- C)Cu2+ D)SO3 E)AlCl3 Lewis acids are electron pair acceptors. Lewis bases are electron pair donors. Look at H2O, for example. .. H:O: .. H This molecule has no "holes" to accept an electron. Would

Page # D-74 How Would You Describe a Dead Skunk? A skunked skunk. no What kind of answers do you have for the ones you have correct? exstankt extinct

page # D-76 What Relation Is a Doorstep to a Doormat? Both are stepped on. no You didn't put any parameters on this and I think its a great answer. How bout the relation being a stepson (steps on) I got astearther.... No wait it's A Step Farther eh....??

43. ## physics

A wooden box, with a mass of 22 kg, is pulled at a constant speed with a rope that makes an angle of 25° with the wooden floor. What is the tension in the rope?

44. ## Chemistry

If 5.026g chromium is combined with 3.04L of chlorine gas at 0.955atm and 220C, what mass of chromium (III) chloride is produced?

45. ## Chemistry

what volume of oxygen at 423.0K and a pressure of 127.4kPa will be produced by the decomposition of 129.7g barium peroxide to form barium oxide and oxygen gas? Thank you

46. ## English

Rewrite the sentences using nouns to replace the phrases in italics. Example: She writes books for a living. She is a writer. 1. Emma loves being a mother. .................................... 2. Having friends is the most important thing for Pepe.

47. ## Math

Question 2 For the function f(x) = 3x2-2x-7, find f(2). Answer f(2) = 13 f(2) = 25 f(2) = 1 f(2) = 1/2 3 points Question 3 One day you work 3 hours and your boss gives you \$22. Another day after working 4 hours your boss gives you \$33. Yesterday after

what lines are foreshadowing I fear, too early: for my mind misgives Some consequence yet hanging in the stars Shall bitterly begin his fearful date With this night's revels and expire the term Of a despised life closed in my breast By some vile forfeit of

49. ## Chemistry

Please help with this question: B) Combustion analysis of a 22.0-mg sample of the painkiller morphine produced 13.2 mg of water. What is the % by mass of hydrogen in morphine?

50. ## Physics

A crate has a mass 24 kg. What applied force is required to produce an acceleration of 3m/s^2 if the frictional force is 90 N.

51. ## college physics

A board of mass m and length L is leaning against a wall. The wall is frictionless, and the coefficient of static friction between the board and the floor is µ. Find an expression for the minimum angle β at which the board can be leaned without slipping.

52. ## Physics

The center of a 1.10km diameter spherical pocket of oil is 1.10km beneath the Earth's surface. Estimate by what percentage directly above the pocket of oil would differ from the expected value of for a uniform Earth? Assume the density of oil is . Express

53. ## Math

1. The random variables X and Y are distributed according to the joint PDF fX,Y(x,y) = {ax2,0,if 1≤x≤2 and 0≤y≤x,otherwise. Find the constant a. 2. Determine the marginal PDF fY(y) . (Your answer can be either numerical or an algebraic function of

54. ## Math

What is greater 3/5 or 3/4

55. ## CHEMISTRY

find the concentrations of H+, HCO3-, CO3 2- in a 0.025M in H2CO3 solutions

56. ## Chemistry

A Sample of propane, C3H8, occupies 5.00L at 270C and 309torr. The volume of the canister is changed to 1.85L while the pressure remains constant. What is the Temperature, in K and 0C, of the gas after the change? What would be the setup for this problem?

57. ## Math

Evan type 72 pages of notes one day. He typed one half of the pages in the morning and one third of the pages in the afternoon. He type the rest of the pages in the evening. How many pages of notes that he typed in the morning and afternoon

58. ## gov

How many votes does each state have in the Electoral College? is equal to number of members the state has in congress Just checking if this is correct.

59. ## chemistry

The amount of organic carbon in a sample can be obtained by IR analysis of the carbon dioxide (CO2) released following complete combustion of the sample in oxygen. A reference sample of an organic compound is usually used to calibrate the instrument

60. ## data

Given the following business scenario, create a Crow’s Foot ERD using a specialization hierarchy if appropriate. Tiny Hospital keeps information on patients and hospital rooms. The system assigns each patient a patient ID number. In addition, the

61. ## Chemistry

For the following reaction, identify the substance oxidized, reduced and the oxidizing and reducing agents. 2SO2 + O2 ----> 2SO3

62. ## physics

Discuss the relationship between motion and force including the following terms: velocity, acceleration, equilibrium, contact force, and field force.

63. ## math

A solar home contains 3.50 multiplied by 105 kg of concrete (specific heat = 1.00 kJ/kg·K). How much heat is given off by the concrete when it cools from 29 to 20°C?

64. ## phsycs

A person shouts in a canyon. 3 s later they hear the echo. How far away is the canyon wall from which the sound wave was reflected? how do i do this problem?

65. ## Ohm's LAW ELECTricity shop

what is the resistance if a circuit with 120v and 5A its 24 how do i make a diagram of a circuit based on the info above

66. ## Math

A box of cereal cost \$3.59 for 30 oz. Find the unit rate.

67. ## Chemistry

The decomposition of HI(g) is represented by the equation: 2HI(g) H2(g) + I2(g) Kc= 64 at 25°C. If the equilibrium concentrations of H2 and I2 at 400°C are found to be [H2] = 5.4x10-4 M and [I2] = 8.8x10-3 M, what is the equilibrium concentration of HI?

68. ## CHEM

How are the forward and reverse rate constants for a one-step reaction related to the equilibrium constant for the reaction? A)Kc = kf x kr B) Kc = kf - kr C) Kc = kf + kr D) Kc = kf/kr

69. ## Biology 205

Can someone please help me? In 1861, Louis Pasteur observed that when yeasts grow in a sugar and protein medium, completely free of air, they ferment vigorously; and for every gram of yeast that forms, 60 to 80 grams of sugar disappeared. If the experiment

70. ## physics

Two pith balls below each have a mass of 5.0 g and equal charge. One pith ball is suspended by an insulating thread. The other is brought to x = 4.0 cm from the suspended ball. The suspended ball is now hanging with the thread forming an angle of 30.0°

71. ## art`1234567890-=1234567890-

im doing my GCSE art exam and have picked the question viewpoints E.g. cubism. so i need some secondary and primary sourses but don't know what do do. what do you suggest?? thanks

72. ## GCSE P.E. 534785623789651982

How did performances at the Sydney Paralympics help in the promotion of disability sport? thanks

73. ## GCSE P.E. 2357238572309

basic rules of curling??

74. ## GCSE P.E. 534785623789651982

How did performances at the Sydney Paralympics help in the promotion of disability sport? thanks

75. ## chemistry7656847547659756946534

what causes the different physical properties between HCl and NaCl

76. ## Science -Electricity

A complete circuit requires an _____ ____ for electricity to flow from the ______to the _______ in the circuit and ______to the battery. I'm trying to fill in the blanks. I think the first two are electric current think the second two are positive and

77. ## Chem

COMPOUND 1 CH2 = CH-CH-OH with CH3 under the second CH Plus CH3-CH-CH2-C (double bond O off C and -OH off C) also a CH3 under CH i) complete the equation for this reaction ii) Indentify any new functional groups in the organic product(s)name them iii)State

78. ## Chemistry

Methanol, CH3OH, is produced on an industrial scale from carbon monoxide and hydrogen. At the temperatures used, gaseous methanol is formed according to the following thermochemical equation: CO(g)+ 2H2(g) CH3OH(g) £H = -90Kj 1. State Le Chateliers

79. ## math

why did the indian wear feathers in his hair. ..brain teaser help How is this related to "math"? I think that it is partially a symbol of status. However, since this is not my area of expertise, I searched Google under the key words "Indian feathers" to

80. ## liver!

After a meal, blood entering the liver has higher levels of what substance than the blood leaving the liver? A.

81. ## bio

4. During the process of photosynthesis, light energy is used directly in the A. formation of ATP B. reduction of NADP C. excitation of chlorophyll electrons D. splitting of carbon dioxide molecules I think it is a or d but i am unsure... It is a or d.

82. ## Maths

When I take 4 times a certain number from 50 the remainder is 6. What is the number?

83. ## Chemistry

Calculate the number of moles of mgcl2 is produced by reacting 168g ofmgco3 with excess hcl(mg=2,c=12,o=16,cl=35.5)

84. ## world history

can someone please check my answers 1.) the purpose of american and european imperialism in the pacific was mainly to gain a.markets for manufactured products b.coaling stations and navel bases c.sources of raw materials d.places for surplus population i

85. ## Physics

Runner 1 is standing still on a straight running track. Runner 2 passes him, running with a constant speed of 1.5 m/s. Just as runner 2 passes, runner 1 accelerates with a constant acceleration of 0.73 m/s^2. How far down the track does runner 1 catch up

86. ## math

A stick of length 1 is broken into two pieces of length Y and 1−Y respectively, where Y is uniformly distributed on [0,1] . Let R be the ratio of the length of the shorter to the length of the longer piece. Find the PDF fR(r) of R . Hint:. What is the

87. ## math

Alice has two coins. The probability of Heads for the first coin is 1/4, and the probability of Heads for the second is 3/4. Other than this difference, the coins are indistinguishable. Alice chooses one of the coins at random and sends it to Bob. The

88. ## math

Alice has two coins. The probability of Heads for the first coin is 1/4, and the probability of Heads for the second is 3/4. Other than this difference, the coins are indistinguishable. Alice chooses one of the coins at random and sends it to Bob. The

89. ## math

A defective coin minting machine produces coins whose probability of Heads is a random variable Q with PDF fQ(q)={5*q^4 if q∈[0,1] A coin produced by this machine is tossed repeatedly, with successive tosses assumed to be independent. Let A be the event

90. ## Physics

a force of 2N Stretches an elastic rubber by 0.2M Find the elastic constant

91. ## Math

Suppose you buy a home and finance \$255,000 at \$2,293.17 per month for 30 years. What is the amount of interest paid? (Round your answer to the nearest cent.)

92. ## chemistry

Use Ksp for PbCl2 and Kf for [PbCl3]− to determine the molar solubility of PbCl2 in 0.10 M HCl(aq). [Hint: What is the total concentration of lead species in solution?]

93. ## Physics0

A) What area of a black body kept at 300°C radiates 100W? B) If a 25m2 roof has a U-value of 0.4Wm^-2 °C^-1, how much heat, expressed in MJ, would escape through it over a day if the temperature inside the building was maintained at 7°C above the

94. ## Physics0

how to estimate the root mean square speed of hydrogen molecules in the earth's atmosphere in km h^-1? thanks for your help, I'm actually teaching myself physics and that why sometimes I get stuck even with simple questions

95. ## Physics0

The currently accepted maximum depth limit for safe scuba diving while breathing air is 50 metres. What is the absolute partial pressure of oxygen at this depth? my solution was as the following, please correct me if I'm wrong: P=F/A Thus the pressure

96. ## physics

A wheel has an initial speed of 100 radians/s. It is then slowed down with a magnitude of the constant angular acceleration of 6.0s^-2. To make it come to rest, how many revolutions does it need to make?

97. ## physics

A plane is in a steep downward plunge. To not crash, Captain Q pulls as much as he can. When the plane is at the lowest point of the plane's path the plane is in a circular arc of radius 450m. Captain Q experiences an acceleration of 5.0g ( so her weight

98. ## physics

Two Small sphere are given positive electrical change. When they are 40cm apart the repulsion force between them has magnitude 0.25N what the charge on each sphere if two changes are equal