1. chemistry

How do you make a venn diagram of the 6 branches of chemistry? (Inorganic chemistry, organic chemistry, biochemistry, nuclear chemistry, physical chemistry, and analytical chemistry) like where would they go in the 3 circles

2. american history

Which of the following statements is true of the Gulf of Tonkin affair? A. Congress was divided and only reluctantly passed the Gulf of Tonkin Resolution. B. The destroyer Maddox was sunk by North Vietnamese gunboats. C. Johnson approved covert amphibious

3. physics

Two arrows are shot vertically upward. The second arrow is shot after the first one, but while the first is still on its way up. The initial speeds are such that both arrows reach their maximum heights at the same instant, although these heights are

4. Physics

A helicopter is traveling with a velocity of 12 m/s directly upward. Directly below the helicopter is a very large and very soft pillow. As it turns out, this is a good thing, because the helicopter is lifting a large man. When the man is 20 m above the

5. earth

The radius of the Earth is approximately 6370 km. If one could dig down straight towards the center of the Earth, one would find that the outermost 2890 km (the crust and the mantle) has an average density of about 4.5 g/cm3. Farther down is the core. If

6. physics

If you have swam one lap in a swimming pool, that means you have swam from one end to the other and back. In 2.5 h, a swimmer makes exactly 29 laps in a swimming pool that is 23 m long. Determine the distance the swimmer traveled, the total displacement of

7. College Physics

A person jumps from a window 34 meters high and is caught in a firefighter's net which stretches 0.6 meter. To the nearest m/s^2, what is the magnitude of the person's acceleration in the net?

8. Physics

A dragster travels 1/4 mile in 6.1 seconds. Assuming the acceleration is constant and the dragster is initially at rest, what is the velocity when it crosses the finish line?plese explain.

9. College Physics I

A helicopter traveling upward at 120 m/s drops a package from a height of 500 meters. To the nearest second how long does it take to hit the ground?

10. chem

over the years, the thermite reaction has been used for welding railorad rails, in incendiary bombs, and to ignite solid fuel rocket motors. The reaction: Fe2O3(s) + 2 Al (s) -> 2 Fe(l) + Al2O3 (s) What masses of iron ( III) oxide and aluminum must be used

11. physics

An image on the screen of a 12 cm long pinhole camera is 7cm. How large is the original object, if it is located 36 cm in front of the pinhole?

13. math

the wheel ( including the tire) of a sports car under development by one of the Big Three auto companies has an 11 in radius. what would be the car's speed in miles per hour if its wheel are turning 800 rpm? ------------------- 800 rev/ 1 min x 60 min/ 1

14. chem

which pair of atoms represent nuclei that have the same number of neutrons? a Co36 and Co 58 b. Mn57 and Fe 57 c. Ni 58 and Fe 57 d. Ni 58 and Co 57 e. Ni 59 and Fe 56

15. Physics

A helicopter traveling upward at 106 m/s drops a package from a height of 500 meters. To the nearest second how long does it take to hit the ground? I'm not sure what numbers to use. What formula to use or anything.. I think 106 m/s is the Vo^2 and 500 m

16. physics

How far to the nearest meter can a sprinter running at 9 m/s, travel in the time it takes a rock to fall 65 meters?

17. math

Calculate the expectation (to the nearest cent) for the Reader's Digest sweepstakes described below. Assume there are 197,000,000 entries.

18. chem

2C2H6(g) + 7O2 -> 4CO2 (g) + 6 H2o (g) What quantity of reactant remains after ignition of a mixture that contains 0.40 moles of C2H6 mixed with 1.60 moles of O2? ( assume maximum reaction according to the equation above)

19. College math

From a survey of 100 college students, a marketing research company found that 60 students owned iPhones, 30 owned cars, and 25 owned both cars and iPhones. (a) How many students owned either a car or an iPhone (but not both)?

20. writing

So, over the summer i had to read the book called the giver by louis lowry, and now i need to write a two chunk paragraph on the differences and similarities between my life and Jonas' life in the community. I already did a paragraph on how they are

21. math

a building cast a shadow approximately 130 ft long on the street when the suns ray form an 82.9 degree angle with the earth. how tall is the building? 180-82.9-90= 7.1 degree tan 7.1 = x/130ft x= 16.19ft is this correct? thanks!

22. Physics

A jet plane lands with a velocity of 100 m/s and can accelerate at a maximum rate of -5.0 m/s2 as it come to rest. Can this plane land at an airport where the runway is 0.80 km long?

23. MATH

Develop a tree diagram for tossing two, eight-sided gaming dice to figure out how many possibilities there are. Discuss the purpose of using such a visual in working out probability.

24. Math

An isosceles triangle has its vertex at the origin and the ends of its base on the parabola y=9-x^2. Express the area of the triangle as a function of the length of its base. Assume its base lies above the x-axis.

25. Chemistry 314

What NaCl concentration results when 254 mL of an 0.880 M NaCl solution is mixed with 412 mL of a 0.450 M NaCl solution?

26. geography

Can you check my answers, please? 1. Latitude is measured north and south of what imaginary line? The Equator 2. Which of the following is not a city: Bangladesh, Tokyo, Amsterdam, New Delhi? Bangladesh 3. What is the name given to a point of land

27. Physics

Standing on the top ledge of a 55 m high building you throw a ball straight up with an initial speed of 29 m/s. How long to the nearest second, does it take to hit the ground? Answer after rounding is 7 seconds. The next question is "If the building in the

28. health

The brain is divided into the _______. A. Cerebrum B. Cerebellum C. Brain stem D. All of the above D?

29. body systems

Veins carry blood ________ the heart. A. Away from B. Towards C. Closer to D. All of the above c?

30. Chemistry

75.0 mL of a 1.80 M solution is diluted to a volume of 258 mL. A 129-mL portion of that solution is diluted using 187 mL of water. What is the final concentration?

31. MATH

Choose a natural number between 1 and 25, inclusive. What is the probability that the number is a multiple of 3?

32. math

A patient is receiving 300,000 units of a medication in 1 Liter of D5W over 24 hrs. How many ml. of medication will be administered per hour?

33. English

1. Tadpole noodles are made from corn. 2. Tadpole noodles are made of corn. (Which one is right?) 3. She is going to go for a hike. 4. She is going to go hiking. 5. She is going to go on a hike. 6. She is going to go out for a hike. (Are the four sentences

34. math

I need help answering the following question: A road sign reads: "5% grade next 4 miles." What is the change in elevation from the lookout to the point four miles ahead (to the nearest foot)?

35. Math

An oil tank is the shape of an inverted right circular cone with the pointed end down. The tank is 15 feet tall and is 12 feet in diameter at the top. At 1:00pm, the tank has oil 5 feet deep in it. Oil is pouring in at 5 cubic feet per minute. To the

36. chemistry

The density of Hexane is 0.659 g/mL. What is the mass of hexane in 25.9 mL?

37. math

Attach 6 trapezoids to one hexagon for each figure Figure 1: One line of symmetry and no rotational symmetries (other than 360 degrees)

38. college algebra

an executive invests \$29,000 some at 7% and some at 6% annual interest. if he receives an annual return of \$1870, how much is invested at each rate?

39. Physics

A 10 kg block sits on a flat surface whose μs=0.60 and whose μk is 0.40 a. What horizontal force is required to get the block move? b.If we continue to apply the same force as in part a. what will the blocks acceleration be?

40. maths

1)lim [(x+y)sec(x+y)-xsecx]/ y x-o 2)show that lim |x-4|/x-4 does not exists x-4 3)lim [1-sinx/2]/[cosx/2{(cosx/4)- x-22/7 (sinx/4)}]

41. world history

with the adoption of hristianity by constantine, the emperor a. stopped using images of pagan gods b. was no longer worshipped as a god c. ended pagan rituals and ceremonies d. was called God's deputy on earth

42. Physics

You are standing at the foot of the Bank of America building in San Francisco, which is 52 floors (237 m) high. You launch a ball straight up in the air from the edge of the foot of the building. The initial vertical speed is 70 m/s. a. How high up does

43. HISTORY

Which of the following statements is most accurate regarding America's political climate between 1876 and 1896? A. Little political power or influence was left to the states. *IS WRONG* B. Southern states tended to vote Republican. C. The influence of the

44. Chemistry

75.0 mL of a 1.80 M solution is diluted to a volume of 258 mL. A 129-mL portion of that solution is diluted using 187 mL of water. What is the final concentration?

45. Physics

A 15 kg box sits on a horizontal force. the coefficient of static fricition between the box and the surface is 0.70. if a force P is exerted on the box at an angle directed 37 degrees below the horizontal, what must be the magnitude of P to get the box

46. Linear Algebra 2 question

Hello, I have another question from my linear algebra class. I'm asked to find the area of a triangle using determinants, but they don't give me the vertices, only the sides. Where A,B,C and D are the vertices, u and v are 2 out of the 3 sides. Now they

47. MATH

A history teacher gives a 27 question T-F exam. In how many different ways can the test be answered if the possible answers are T or F, or possibly to leave the answer blank?

48. College Physics

I keep getting answer wrong. I don't know what I did wrong. I really need help please. I need help with 1 question. Can you help with this please if you don't mind? 1) Suppose you are given that z = c y^3/x^2 where c is some number. For a particular value

49. Communication

Hello! I need help with my research regarding-- Twitter being used as a prime source for real time news. Can anyone suggest a communication theory I can use for this study? I was thinking about using the agenda-setting theory, but I need another theory

50. Physics

A 160lb person steps into an elevator and stands on a bathroom scale. what is the weight on the scale when the elevator accelerates upwards at 2ft/s^2

51. chemistry

A nitrogen atom has 7 protons, and its most common isotope has 7 neutrons. A radioactive isotope of nitrogen has 9 neutrons. What is the atomic number and what is the mass number of this radioactive nitrogen? Show all of your work for full credit

mr.wilson charges 215 dollars a month to board horses. if he boards a total of 25 horses,how much money will he earn? please show your work. my answer is 5,375 am i right if not please tell me why and how.

53. health

How is cardiac muscle similar to smooth muscle? A. Both are striated B. They share no similarities C. They share no differences D. Both have one central nucleus D?

54. poetry

Line from "To Her Father With Some Versus", Yet for part payment take this simple mite possible answers 1)bedbug 2)a coin of little value ** 3)physical strength 4)possibility How many couplets are in this poem? 1)five 2)six 3)seven 4)fourteen*** Which of

One of the reasons that certain advertisements are successful is because viewers want to behave like those they observe. What is the general term that psychologists use to describe this type of behavior?

56. math statistics and probability

how many 4 digit number can be formed from the digits 2,3,5,,6,7,8 if: a.)each digit be only used once b) how many are even? c) how many are odd? d) how many are greater than 25000?

57. College math

A student is asked to answer 7 out of 9 questions on an exam. (a) Classify the problem as a permutation, a combination, or neither.

Sort the pairs of related compounds by their carbonyl stretching frequencies in cm–1. (There will be three compounds per bin.) Bin # 1: Slightly higher Bin #2: Slightly lower Compounds: -butanol -but-2-enal -heptan-3-one -hept-4-en-3-one -cinnamaldehyde

59. Physics

A fire hose can project water at a rate of 6.00x10^2 litres per minute to a height of 40.0m. Find: a) the velocity with which the water leaves the tube b) the kinetic energy of the water as it leaves the hose c) the kinetic energy of the water at 40.0m.

60. physics

Anne throws a ball straight up releasing it from her hand with an initial speed of 20 m/s. The ball is at a height of 1.5 m above the ground when it is released. Determine the maximum height of the ball? Calculate the ball’s speed just before it hits the

61. Physics

A 10 kg block sits on a flat surface whose μs=0.60 and whose μk is 0.40 a. What horizontal force is required to get the block move? b.If we continue to apply the same force as in part a. what will the blocks acceleration be? In the answer: force=.6*mg to

62. ACCT

How might the choice of cost flow assumptions affect the company's cost of goods sold and ending inventory balance?

63. accounts

A prospective investor has hired you to develop a worksheet that will compute the book value per share on each class of stock of various companies. Your worksheet should include a Data Section. One of the companies the investor is currently interested in

64. ap chemistry

name five organic compounds that melt between -40 degrees and -49 degrees celsius

65. Algebra

Please help me with this algebra question?!?!?!? Find the discriminant of the equation in terms of p and q. Suppose q

three bothers earned a total of \$3,500. larry earned twice as much money as jim while adam earned half as much money as jim. how much money did jim earned? please show your work. my answer is 1000 am i right if not please tell me why and how.

67. Math

Answer check please: Consider the circle (x-3)^2 + (y+1)^2 = 169. The point (15,4) is on the circle. Find an equation for the line that is tangent to the circle at this point. I got y= 5/12x-9/4.

68. math

\$20,000 \$10,000 \$11,000 \$4,000 \$30,000 \$25,000 \$5,000 Calcuate current ratio. Calculate acid test averae days colletion. Calcuate profit margin on sales.

69. physics

A person throws a rock straight up into the air. At the moment it leaves the person's hand it is going 91 mph. When the rock reaches its peak, how fast is it going and what is the magnitude and direction of its acceleration? Ignore air drag

70. physics

A car goes 10 km in 5 minutes when its average velocity is 80 km/hr. true or false

71. physics

A car accelerates from 10.0 m/s to 30 m/s at a rate of 3.5 m/s2. How far does it travel while accelerating?

72. health

Diastole is the ________ phase of the cardiac cycle. A. Contraction B. Relaxation C. Monitoring D. Termination c?

73. maths/physics

PLEASE HELP! A POINT SOURCE OF LIGHT IS PLACED 50 CM ABOVE A CIRCULAR CARD OF DIAMETER 5CM, THE SOURCE BEING DIRECTLY ABOVE THE CENTRE OF THE CARD. WHAT IS THE AREA OF THE SHADOW ON THE FLOOR 70 CM BELOW THE CARD?

74. alegrbra

A tugboat is going 100 miles upstream in 10 hours and returning downstream in 5 hours. What is the boats speed and the speed of the current?

asked by a tugboat is going 100 miles upstream in 10 hours and returning downstream in 5 hours. What is the s
75. world history

most sages of the aial age took which of the following views of human nature? a. it's neither good nor bad b. it's essentially bad c. it's pre-determined d. it'sd essentially good

76. nervous system

The pulmonary circuit and the ________ circuit make up the blood vessels of the body. A. Flexible B. Systemic C. Blood D. Capillary c?

77. math

solve equation then check for extraneous solution please someone explain this to me. 6/6-4x/=8+4 then one that is solve the inequality s/x+3/4

78. medical terminology

identify and list 3 of the 12 organ system as well as the organ cantained in these systems within the human body. identify which anatomical region the organ system are located within.

79. geography

Thank You and I did some more questions. Can you check them? 1. Is the Antarctic Circle north or south of the equator? South of the equator 2. All lines of longitude are measured east and west of what imaginary line? The Prime Meridian. Ms. Sue the 9th

80. math strayer

Find the probability whose odds against are given in the problem. Odds against are 3 to 7.

81. English

What literature do you consider to be part of the United States' current literary canon? Why?

82. College Physics

Convert 15.9 miles/hr to m/s

No, I did not check Reiny's answer that night. I did check it just now and it is the same answer I got the very first time I did the problem,but my Dad did not agree with me at that time. He did later after going over and over it. Thanks Ms. Sue. We just

84. math statistics and probability

A costumer has to buy a cell phone from an appliance store with 8 different brands. Each brand is available in 5 different colors, and 7 origins. how many choices can the sales lady offer the costumer?

85. english

identify parts of speech to this sentence Over a three month period he was able to win her over to his point of view.

86. math statistics and probability

the set S={x|x^2+4x-5=0}

87. Algebra with Applications

Suppose an insurance agent offers you a policy that will provide you with a yearly income of \$150,000 in 25 years. What is the comparable annual salary today, assuming an inflation rate of 4%?. (Round your answer to the nearest cent.) I think I would solve

88. Physics

A 10 kg block sits on a flat surface whose μs is 0.60 and whose μk is 0.40 a. What horizontal force is required to get the block move? b.If we continue to apply the same force as in part (a) what will the blocks acceleration be???

89. math

Shawn bought a hoe for \$100,000. He put 20%down and obtained a mortage for 30years at 5 1/2%, what was the total intrest cost of the loan

90. Sociology

Which is true about conducting research? a) It is easy and anyone can do it b) The problem you pick is less important than how you study it c) It is a sophisticated art that scientists learn as they gain professional insights and skills d) It is usually

91. process control

Average power (btu/s) needed for a process that heats water at 40 lbm/min from 20F to 150F. Can you just tell me generally how to solve a problem like this. The numbers do not really matter, I just need to practice problems. Thanks.

92. accounts

Package Plus, Inc. has \$2,000,000 of 10% bonds outstanding on December 31, 20X8. On January 1, 20X9, WrapIt Corporation, an 80%-owned subsidiary of Package Plus, Inc. purchases a \$200,000 part of Package Plus, Inc.’s outstanding bonds in the market for

93. Physics

Why is parallel circuit brighter compared to series? ( Only one bulb is present in both circuits) Thanks :)

94. social studies

Is the former name of the Democratic Republic of the Congo Zaire?

95. Chemistry (science)

I don't know how to answer this. An aqueous solution of glucose has a freezing point of -0.37. What is the concentration of the solution?

96. mat

Sally claims that it is easier to add two fractions if she adds the numerators and then adds the denominators. How can you help her?

97. Algebra

2006, 74.2 million tax returns were filed electronically. This represents a 108.8% increase over the year 2005. How many income tax returns were filed electronically in 2005?

Solve this pair of equations by the graphical method: 4x+y=9 , 3y-2y=49

99. math

analyze the graph of the function. what is the domain of f(x)? f(x)=x^2+x-72/x+7 {x|x is not equal to -7} there are other answers, but i think its this one, am i correct?

100. Science/History - Sally Ride

What are some interserting facts about Sally Ride? I am doing a presentation on her and I read that she died this summer. I also have some other information, but I need some more help.

101. Calculus AP

im still stuck. i need help. evaluate the integral ∫sinx /(1+x^2) dx from -1 to 1

102. Physics

A rok is thrown 24 meters/sec upward and lands in a 10 meter deep hole. How long is the rock in the air until it reaches the bottom of the hole?

103. english

As teachers on this board. How can I help my son to improve on his spelling, he is in the 6th grade?

104. math

I need help with the following question: While fishing on a lake, you see a fish below water at a 25 degree angle with the surface, producing air bubbles on the surface of the water 20 feet ahead. How far away is the fish from the boat?

105. algebra

use the intermediate value theorem to show the polynominal function has a zero in the given interval f(x)=x^5-x^4+3x^3-2x^2-11x+6; [1.5,1.9] x= -2.33 y=10.19 after i plugged in the 1.5 and 1.9 i just want to know if my x and y are correct

106. Math

A truck tire with a diameter of 36 in is rolling over level ground spinning at 11 rotations/second. If the speed limit is 55 miles per hour and the penalty is \$20 per hour over the speed limit, should the driver be fined and if so, how much?

107. English

Could you help me find the "simple subject" and "simple predicate" in the following sentence please? "It is going to rain tomorrow." Thank you!

108. physics

why it is easier to tear a paper off a full roll than a mostly used one? Is it because of Newton's law?

109. Physics

A person drops a small rock from a bridge. If it takes 1.70 seconds for the rock to reach the water below the bridge, how high was the bridge above the water? please explain.

110. infomation lteracy

which of the following keyword search should retrieve the the most results in an online database? a.beta b.beta AND blockers c. beta OR blockers d. beta NOT blokers

111. health

Nearly ________ movement in the body is the result of muscle contraction. A. All B. 50% of all C. 10% of all D. None of the above D?

112. physics

A car accelerates from 10.0 m/s to 30 m/s at a rate of 3.1 m/s2. How far does it travel while accelerating?

113. accounting

Find the ending balance in an account that opens with \$9,000, earns 4.5% interest compounded quarterly, and is held for 5 years. (Round your answer to the nearest cent.)

114. Linear Algebra

Knowing u = (4,0,-3), v = (x,3,2) and that the orthogonal projection of v on u is a vector of norm 6, determine x. Thank you

115. math

A car dealer will sell you a used car for \$8,544 with \$544 down and payments of \$272.22 per month for 36 months. What is the simple interest rate? (Round each answer to the nearest tenth.)

116. math

the area of circle B is 36 times greater than the area of circle A. The radius of circle B is 30. what is the radius of circle A

117. Math

Find the slope of the line passing through the points (0, -4) and (-6, 7)

118. chemistry

what is the amount of heat required to heat 3.3kg of gold from 29 degrees celcius to 61 degrees celcius

119. sol 102

A philosophical argument should involve

121. math

absolute value equation 2/3x-5/-8=8 Can someone help do not understand

122. ALGEBRA

1.2G DIVIDED BY 3CM TO THE THIRD POWER

123. Math

What is the lcm for 5,15, and 24?

124. Calculus AP

integral of [sqrt(u) - 2 u^2]/u du i got stuck ∫u^-1 (sqrt(u) - 2 u^2) du ∫ u^(-1/2) - 2u du i don't know i'm doing right step

125. chemistry

does the number 340 have the same meaning as the number 340.0??

126. chemistry

An electronic balance shows the number 2.705 grams ; which digits is/ are the uncertain digit and which are the significant digit?

127. Pre-algebra

5(a-b)-7(a-b)+8(a-b)Y

128. History

What type of tomb became popular after the pyramids?

129. math

One line of symmetry and no rotational symmetries (other than 360 degrees) im supposed to draw this but idk what it is

130. MATH

What is the probability of obtaining a sum of at least 7 when rolling a pair of dice?

131. Sociology

Which type of research will probably cost the most? a) Interviews b) Field research c) Document analyses d) Questionnaires I am leaning towards (b)

132. Sociology

Why is it difficult to obtain population level data? a) It is expensive b) It is time consuming c) It is hard to find everyone in the population d) All of the above I am thinking (c)

133. chemistry

How do you draw an orbital diagram for an element, for example, the element iron.

134. math

\$ 20,000 10,000 11,000 4,000 30,000 25,000 5,000 what is the curent ratio

135. biology

how did the surface area affect the diffusion of the cube?

136. Math

Can you please check my answers, thank you #2. 5/y+4 + 11/y^2=y-12 = 7/y-3 Answer -2 #4 The length of a rectangle is 2 cm more than twice its width. If the perimeter of the rectangle is 40 cm, find the length of the rectangle. A. 6 cm B. 9 cm C. 11 cm D.

137. Calculus AP

i got the wrong answer. the correct answer is ln(2). here is problem: ∫cosx/(1+sinx) dx from 0 to pi/2

138. Physic

Type A nerve fibers in humans can conduct nerve impulses at speeds up to 139.8 m/s. How fast is this in mph? This is a question from my physic homework. I have tried converting 139.8 m/s to mile then to hrs and i got .000241 mph. When I input it it said

139. chemistry

how many capacity of water and alcohol in .90g/ml dilute alcohol

140. Physics

Forcefriction=(Psin37+15*9.8)*.70 So Pcos37 must equal to the force, solve for P. how to get the magnitude of P??how to solve for P. thanks a lot~~

141. psychology

explain any five exceptions to learning

142. ODE

if the DE x^2.y"+xy'-y=0 has a general solution c1x+c2.x^-1, use the variation of parameters to find the particular solution x^2.y"+xy'-y=2-2/x

143. physics

a rod 300 cm long is hinged in a wall its weight is 50N. it is supported by a leg from other edge and an external weight of 80N is placed on the rod 50 cm away from the leg end.. find the tension in the leg?

144. a

Bentley Biscuits, a wholly-owned English subsidiary of U.S. Bakery (a U.S. firm) maintains its inventory at cost, and Bentley Biscuits’ books are reflected in British pound sterling. U.S. Bakery's functional currency is U.S. dollars. Determine the

145. physics

The vector V is given by V = (5.0x-12.0y )m. What is W such that V + W = -5|V|x?

Use substitution method to solve x-2y-5=0, 3x-5y=8

Solve this pair of equations by the graphical method: 4x+y=9 , 3y-2y=49

148. geometry

I'm stuck on this question please help. "Lines p and q intersect to form adjacent angles 1 and 2.If angle 1=3x+18 and angle 2=-8y-70,find the values of x and y so that p is perpendicular to q.

149. Chemistry

When 50% potassium hydroxide is diluted to 4% with water - a white precipitate is formed.Can you tell me why and what the precipitate us?

150. health

What is stress management? A. Controlling and reducing the tension that occurs in stressful situations B. Controlling and reducing the tension that occurs in peaceful situations C. Controlling and reducing the happiness that occurs in peaceful situations

151. History

What are the boundaries of the Egyptian empire?

152. psycology

One consequence of providing an inaccurate opertional definition of the properties we intend to measure, is that the measurement will be: Invaild, Reliable, Valid or Powerful

153. psycology

a professor gives his 100 studebts an axam and everyone gets an A. the exam lacks_______ to detect which students studied and which didn't sample size reliability power significance

154. physics

100 lumen of light are incident on an interface which has 25% reflectance. At a point 3cm into the new medium, the amount of transmitted light is measured as 50 lumen. What is the absorptance of the material per cm?

In this book I'm reading one of the questions ask: What is the significance of Bean finding the color blue? What does the question mean?