# Ellen

Newest questions and responses by Ellen
1. ## Physics

When light of wavelength 450 nm is passed through a certain diffraction grating, the first order diffraction maximum is found to be at an angle of 35° to the straight through. Calculate the distance between adjacent slits in the grating.

2. ## Physics

A certain radioactive nucleus emits a gamma ray with an energy of 0.186 MeV. Calculate the mass lost by the nucleus during the decay process.

3. ## Physics

The respective charges on three identical metal spheres (q1, q2 and q3) are ̶ 16.9 µ C, 5.60 µ C and 2.6 µ C. The spheres are brought together so that they touch each other, and are then separated and placed on the x and y axes. Calculate the net

4. ## Math

An apple pie uses 4 cups of apples and 3 cups of flour. An apple cobbler uses 2 cups of apples and 3 cups of flour. You have 16 cups of apples an 15 cups of flour. When you sell these at the Farmers market you make \$3.00 profit per apple pie and \$2.00

5. ## Math

An apple pie uses 4 cups of apples and 3 cups of flour. An apple cobbler uses 2 cups of apples and 3 cups of flour. You have 16 cups of apples an 15 cups of flour. When you sell these at the Farmers market you make \$3.00 profit per apple pie and \$2.00

6. ## math

perform the indication operation. express the answer in simplest forms

7. ## english

Hello! Is this good thesis? How can I make it better? I would recommend this novel to other readers because it is mysterious, appeals through emotions, but hard to understand some of the context. Thank you.

8. ## Chemistry 30

How do i do this question?? A 10.00ml Sample was taken from a 2Liter Container of Tropicana Orange juice. This sample was analyzed for its citric acid content by titration with a known 0.1112M NaOH base solution. A Phenoolphthalein indicator was added to

9. ## maths fractions

Marian had some pie. She ate ¼ of the pie. Now there is 1/3 left. How much pie did she originally have?

10. ## Science

Some people prefer to use herbal medicines how will you know if they actually work? Thanks.

11. ## Science

What damage to the environment can the use of plant hormones cause? Thanks.

whats is in their decision making process(How Gerber Used a Decision Tree in Strategic Decision-Making), can someone explain it to me because i don't get it. I'm going to need it for my assignment which is to Present and Give Observation on a Sample

13. ## Math

The area of a rectangle is 222 sq feet. What is the length of its sides?

14. ## Chemistry - acids & bases

4. Calculate the pH of each of the solutions and the change in pH to 0.01 pH units caused by adding 10.0 mL of 2.37-M HCl to 320. mL of each of the following solutions. Change is defined as final minus initial, so if the pH drops upon mixing the change is

15. ## History

Which of the following best describes a long-term political effect of the civil rights movement? A. The Democratic Party lost most of its support among white southern voters. B. African Americans came to dominate state legislatures across the South. C.

16. ## math

The ratio for red and blue skittles is 3:5. There are 20 more blue skittles. how many red skittles are there?

17. ## Biochem

Using stocks of 0.1 M KH2PO4 and 0.1 M K2HPO4 how much 0.1 M K2HPO4 is needed to prepare 20 mL of a buffer solution at pH 7.2. The pKa of phosphate is 6.82. I know to solve for the ratio using henderson hasselbach but im lots after that! 5.2=6.82+log(A/HA)

18. ## math

which property is illustrated by the equation 5/6(-11)=-11(5/8)

19. ## Math

Mark makes 10% of 100, Lindsay makes 5% of 400, Kelly makes 15% of 100, what's the median average?

20. ## Math

What is the unit rate of drink 4/5 L in 1/4 hour

21. ## Chemistry

To completely react 17g of barium hydroxide, how many grams of hydrochloric acid is needed?

22. ## math

Solve the volume of a cylinder with diameter (4 +2x)m, height (5x+1)m v=pi [(4+2x) x (5x+1)]

23. ## 1 Science Question Unanswered

Okay... I got all the answers. Thanks for the helps anyways. :( I just at least need one help. 1. In plants, sexual reproduction occurs when sperm and egg unite to form a... a. gamete b. gametophyte c. sporophyte d. zygote Is it a or d?

24. ## Science

1. In plants, sexual reproduction occurs when sperm and egg unite to form a... a. gamete b. gametophyte c. sporophyte d. zygote Is it d? 2. A plant continues to grow throughout its life through the use of s a process called... a. alternation of generations

25. ## Science

1. In plants, sexual reproduction occurs when sperm and egg unite to form a... a. gamete b. gametophyte c. sporophyte d. zygote Is it d? 2. A plant continues to grow throughout its life through the use of s a process called... a. alternation of generations

26. ## Physics

A 1000Kg car is traveling at 40 m/s. a.) if the car stops in 20 seconds, what is the deceleration rate? b.) what friction force will stop the car in 20 seconds?

27. ## Mathstatistics

For example is this considered to be appropriate selected statistical test "(50)equal -0.45,p positive .50?

28. ## Math

The weight of a person and his luggage should not be greater than 150kg when travelling; (i) If the weight of the laggugge is W and that of a person is 70kg. write an inequality to represent this information (ii) Solf the inequality to find the range of

30. ## Chemistry

2Mg(s) + O2(g) 2MgO(s) If 9.92 g of Mg reacts with 8.52 g of O2. How many grams of MgO could be produced? I am just very confused and need an answer so that I can look back on how you got there . . .

31. ## English

Examples of letters to the person you picked (on the draw lots)

32. ## physics

a compound consist of carbon,hydrogen and oxygen only.the percentage by mass are carbon 40.0% and 6,7% hydrogen.calculate the empirical formulae

33. ## Calculus

The following table shows the percentage of the U.S. Discretionary Budget allocated to education in 2003, 2005, and 2009 (t=0 represents 2000) Year t 3 5 9 Percentage p(t) 6.8 7 6.2 (a) Compute and interpret the average rate of change of P(t) (b) Over the

34. ## Chemistry

How would you write the net ionic equation for [Co (en) 2Cl2]Cl with AgNO3. Is it AgNO3 ----> Cl^- + 3Ag^+?

35. ## math

what percentage more is 2200 than 1725.

|3x+1|-|2-x|

37. ## chemistry

The Henry's law constant for CO2 at 20°C is 3.7*10^-2 M/atm. What mass of CO2 (in grams) is present in 355 mL of soda drink if the pressure of CO2 in the can is 2.5 atmospheres at 20°C? (Assume the solubility of CO2 in the soda is the same as water)

38. ## SAT prep help

if -2x+5=2-(5-2x), what is the value of x?

39. ## Chemistry

Write the total and net ionic equations for the following molecular reaction: HgNO3 (aq) + NaCl (aq) -> HgCl (s) + 2 NaNO3 (aq)

40. ## math

Gail and 3 friends all share 1/2 a pie. All the pieces in pie put together make up 180 degrees. Gail and friends finish the pie and each eat an equal piece. They believe each piece has an angle of 25 degrees. Are they right?

41. ## chemistry

How many grams of I2 are present in a solution if 33.75mL of 0.140M Na2S2O3 solution is needed to titrate the I2solution?

42. ## math

A t-shirt manufacturer uses 5/8 yard of material for each shirt, how many shirts can be made fro 14 & 38 yards of material?

43. ## math 15

find the minimum height above the surface of the earth so that the pilot at point a can see an object on the horizon at c 125 miles away. assume the diameter of the earth to be 8000 miles.

44. ## Macroeconomics

If the government imposes a price ceiling of \$100 on a market, what would happen in the market as a result of protests of price gauging by the sellers? What would happen to the price and quantity in the market?

45. ## Pre Calc 12

Four consecutive integers have a product of 360 Find the integers by writing a plynomial equation that represents the integers and then solving algebraically.

46. ## Pre Calculus

mx3-nx2+5x-1 is divided by x-2 the remainder is -39. When divided by x-1 the remainder is 3. What are the values of m and n. Didn't know how to do the superscript for mx3

47. ## chemistry

how many molecules are present in 1.2 mol of glucose, C6H12O6?

48. ## science

What does chlorophyll do for plants?

49. ## literature

What are the major events in Act I of A Doll's House?

50. ## Algebra

Solve using set builder notation, show all work. 12x-25 is greater than or = to 3x-5(x+6)

51. ## math

A square is made up of section A and section B. Section A is 500 sq. ft. and section B is 750 sq. ft. What percent of the square is section A? *

52. ## math help

Universal instruments found that the monthly demand for its new line of Galaxy Home Computers t months after placing the line on the market was given by D(t) = 2900 − 2300e−0.08t (t > 0) Graph this function and answer the following questions. (a) What

53. ## math help

determine the intervals where f(x) = e^((-x^2)/2) is increasing and where it is decreasing

54. ## algebra

What is the answer for 4.(5)(5)-35+21-(-3)(-3)(-3)

55. ## Inverse Functions

Given that g is the inverse function of f, and f(3)=4, and f'(3)=5, then g'(4)= ?

56. ## math

The call letter of a radio station must have 4 letters.The first letter must be a K or a W. How many different station call letters can be made if repetitions are not allowed? *(If repetitions are allowed?)* *Important

57. ## math

The call letter of a radio station must have 4 letters.The first letter must be a K or a W. How many different station call setters can be made if repetitions are not allowed? If repetitions are allowed? I have the answers just need to know the work

58. ## biology

what all do i need to know for GCSE biology my teacher is absolutely rubbish i tried websites but i don't find them helpful thankyou

59. ## Chemistry

The formaldehyde content of a pesticide preparation was determined by weighing 0.3124g of the liquid sample into a flask containing 50.0mL of 0.0996M NaOH and 50mL of 3% H2O2. Upon heating, the following reaction took place: OH- + HCHO + H2O2 -> HCOO- +

60. ## Chemistry

A 25.00mL sample of a household cleaning solution was diluted to 250.0mL in a volumetric flask. A 50.00mL aliquot of this solution required 40.38mL of 0.2506 M HCl to reach a bromocresol green end point. Calculate the weight/volume percentage of NH3 in the

61. ## Chemistry

What is the likely source of error from reading a graph where the absorbance (y-axis) versus concentration (x-axis) shows non-deal behaviour. The graph is going in what looks like a line of best fit but then curves off a the end. At the end of the graph

I'm so confused with these-please check them. ¿Estudias algo los sábados? No, no estudio nada los sábados.Do I need the no, no or just one no, estudio? ¿Hablas a francés a veces? No, no hablo nunca a francés. Once again, do I need no, no hablos or

63. ## Spanish-Check please! I need help

Please check-I'm having a problem interpreting these questions and I have to answer them for homework. Could you please check my translation I'm not sure what these questions mean and I have to answer them for homework ¿Qué necesitas para comer en

I'm not sure what these questions mean and I have to answer them for homework ¿Qué necesitas para comer en cereal?does this ask what I need to eat cereal-like a spoon , bowl etc? 2. ¿Qué ríes mucho cuándo miras a los payasos?Do you laugh alot when

Él no va nunca.He never goes Él ve alguien.He sees someone. Él no ve nadie.He doesn’t see anyone.

66. ## Physics

Consider a frictionless track as shown in the figure below. A block of mass m1 = 5.75 kg is released from A. It makes a head on elastic collision at B with a block of mass m2 = 8.00 kg that is initially at rest. Calculate the maximum height to which m1

67. ## uncc

the half-life of 234U, uranium-234, is 2.52 x 10^5yr. If 98.5% of thee uranium in the original sample is present, what length of time (to the nearest thousand years) has elasped

68. ## Chemistry

Calculate the pH of a 0.10 M NaHX salt solution. Ka (H2X) = 2.1 x 10-2 Ka (HX-) = 4.5 x 10-8 Can someone explain the steps to do this please?

69. ## physics

A projectile is fired straight up at a speed of 15 m/s. How long does it take to reach the top of its motion? The acceleration of gravity is 9.8 m/s2 .

70. ## physics

A projectile is fired straight up at a speed of 15 m/s. How long does it take to reach the top of its motion? The acceleration of gravity is 9.8 m/s2 .

71. ## calculus

find all points at which the tangent line to the graph of y=x3 is parallel to the line y=27x+5

72. ## Physics

Two objects attract each other gravitationally with a force of 2.9 10-10 N when they are 0.29 m apart. Their total mass is 4.0 kg. Find their individual masses.

73. ## science

One of the characters Mendel studied was the position of the flowers. He crossed plants that had flowers at the tips of the stems with plants that had flowers along the sides. He allowed the F1 plants, which had flowers along the sides, to self-fertilize.

74. ## science

A segment of double-stranded DNA contains 31% Adenine (A) bases. a. What are the percentages of the other three bases in the DNA segment? (Count bases on both strands.) C: T: G:

75. ## science

There are about 300,000,000 US citizens. If we wanted to assign each person a unique identifier, using DNA sequences, how long a DNA sequence would we need? (Here’s another way of phrasing the question: How many bases of DNA are required for there to be

76. ## Math

The measure of one angle in a linear pair is 30 more than twice the measure of the other angle. Find the measure of the angles. (I really need help! Thanks)

77. ## chemistry

A glass apparatus contains 26.223 g of water when filled at 25 °C. At this temperature, water has a density of 0.99704 g/mL. What is the volume of this apparatus?

78. ## chemersty

Calculate the value of the following in exponential form, using standard scientific or "e" notation (for example, 105 = 1.05e2). Enter your answer with the correct number of significant figures. 885.75 g + 10.151 g - 25.50 g

79. ## Maths

Stuck! Help! 2.5 cubed? Xxxxx

80. ## math

in a distribution of 160 values with a mean of 72,at least 120 fall within the interval 67-77. approximately what percentage of values should fall in the interval 62-82? use chebyshev's formula.

81. ## science

lena carried out an investigation to find the energy content in bacon rind she lit the bacon rind with a bunsen burner and held it beneath a test tube of water she stirred the water and recorded it temperature! why did lena stir before recording the

82. ## science

the list below shows three ways in which metals can react. a) strongly heat the metal in the air. b)add small pieces of the metal to cold water. c)add small pieces of the metal to dilute acid. in each case choose a b or c calcium oxide hydrogen (using

83. ## Physics

Consider a pendulum of length 4.557 m. The acceleration of gravity is 9.832 m/s2 . a) What is its period at the North Pole? Answer in units of s. b) What is its frequency? Answer in units of Hz. c) What is its period in Chicago, where g = 9.803 m/s2?

84. ## Physics

A trapeze artist swings in simple harmonic motion with a period of 3.2 s. The acceleration of gravity is 9.81 m/s2 . Calculate the length of the cables supporting the trapeze. Answer in units of m.

85. ## Physics

A mass of 0.38 kg is attached to a spring and is set into vibration with a period of 0.22 s. What is the spring constant of the spring?

86. ## math (calculus)

A cap of a sphere is generated by rotating the region about the y-axis. Determine the volume of this cap when the radius of the sphere is 5 inches and the height of the cap is 1 inch.

87. ## math (calculus)

A cap of a sphere is generated by rotating the region about the y-axis. Determine the volume of this cap when the radius of the sphere is 5 inches and the height of the cap is 1 inch.

88. ## Physics

The hoover dam produces 2x10 to the 9 W of electricity. It is composed of 7x10 to the 9 kg of concrete. To produce 1 kg of concrete requires 1 MJ of energy. How much energy did it take to produce the dam? How long was the "energy payback time" for the dam?

89. ## Physics

the relationship between rotational speed and net force is direct right? and also can u say why it is direct

90. ## physical science 2

It takes 6 seconds for a stone dropped from rest to the bottom of a well,what is its final speed A; 6 meters/second B: 30 meters/seconds C: 36 meters/seconds D: 60 METERS/SECONDS A is incrrect

91. ## Physical Science 2

Ten seconds after starting from rest,a freely falling object will have a speed of about______ rn/s A: 10 B: 50 C: 100 D: 120 I know that the answer A is not correct.

92. ## physical science 2

A block is dragged at constant velocity in a straight line path across a level surface by force of 6 N. What is the friction between the black and the surface? a: 6 N B: less than 6 N C: More than 6N d: ZERO

93. ## physical science 2

the force required to maintain an object at a constant velocity in free space is equal to: b: the mass of the object. c: the force required to stop it. d zero

94. ## physical science

A kg ball of lead rests next to a 10 kg rock. which statement below is true:a:the lead ball and rock have the same amount of inertia,b:if the lead ball and the rock fell from the same height in a vacuum, the rock would hit the ground first because it is

95. ## physical science

a car traveling in a lage circlepasses by a motorcycle that is trveling in a straight line north to south.both of their speedometers read 10m/s.which statement is true; a: the car and motorcycle have the same speed ,but different velocities,b:the car and

96. ## physics

The centers of a 6.0 lead ball and a 70 lead ball are separated by 8.0 . What gravitational force does each exert on the other? What is the ratio of this gravitational force to the weight of the 70 ball?

97. ## Chemistry

A calorimeter contains 21.0 mL of water at 14.0 degreesC. When 1.90 g of X (a substance with a molar mass of 70.0 g/mol) is added, it dissolves via the reaction X(s)+H_2O(l)reacts to make X(aq) and the temperature of the solution increases to 28.5degreesC.

98. ## Chemistry

80.0 mL of water is initially at room temperature (22degrees C). A chilled steel rod at 2 degrees C is placed in the water. If the final temperature of the system is 21.2 degrees C, what is the mass of the steel bar? Specific heat of water =

99. ## Chemistry

Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of Helium is present in a helium-oxygen mixture having a density of 0.538 g/L at 25 degrees C and 721 mmHg?