# Questions Asked onFebruary 16, 2015

1. ## main idea

This question is based on the following passage. Both Seagulls and wild geese are large birds. They're also similar in that both kinds of birds can fly over great distances. On the other hand, seagulls are scavengers, while wild geese aren't. Seagulls, for

asked by stevenson high school
2. ## Physics

A group of students observes that a wooden block (m = 0.40 kg) on the end of a string with a radius of 0.7 meters makes 8 rotations in 20.7 seconds when twirled. What is the block's tangential (linear) speed? What is the block's angular speed?

3. ## Science

What is the differnce between the way matter responds to a transverse wave and a longitudinal wave? A. Matter moves in the same direction in a longitudinal wave, and at right angles to the direction of a transverse wave. B. Matter moves at right angles to

4. ## Physics

A group of students observes that a wooden block (m = 0.40 kg) on the end of a string with a radius of 0.7 meters makes 12 rotations in 20.7 seconds when twirled. Calculate the centripetal acceleration of the wooden block: Calculate the tension in the

5. ## math

Straub's Bakery makes 200 Danish cakes that cost \$2.70 each. Straub's needs a 66% markup on cost and normally discards 10% of what it makes. At what price should Straub's sell the Danish cakes?

6. ## Probability

Consider the communication network shown in the figure below and suppose that each link can fail with probability p. Assume that failures of different links are independent. Assume that p=1/3. Find the probability that there exists a path from A to B along

7. ## Physics

In a hydroelectric installation, a turbine delivers 1500 hp to a generator, which in turn transfers 80.0% of the mechanical energy out by electrical transmission. Under these conditions, what current does the generator deliver at a terminal potential

8. ## Science

When a wave enters a new medium, slows down, and bends, the wave undergoes A. Reflection. B. Absorption C. Refraction D. Reduction Is the answer C? Thank you

9. ## Physics

Assume the distance axis is linear and da = 10.0m and db = 35.0 m. Estimate the work done by a force F in moving a 2.80 kg object from da to db.

10. ## math

a sample consists of the following n =6 scores: 2, 7, 4, 6, 4, and 7 compute the mean and standard deviation for the sample

11. ## life orientation

clarify how intrapersonal conflict can lead to emotional stress

12. ## Chemistry

Nitrogen dioxide reacts with carbon monoxide to produce nitrogen monoxide and carbon dioxide in the reaction, . The first step in the reaction is proposed to be two NO2 molecules colliding to form NO3 and NO. The NO3 intermediate then reacts with CO to

13. ## physics

A group of students observes that a wooden block (m = 0.40 kg) on the end of a string with a radius of 0.7 meters makes 5 rotations in 20.7 seconds when twirled. 1)Calculate the centripetal acceleration of the wooden block: 2)Calculate the tension in the

asked by phys 220
14. ## Physics

A group of students observes that a wooden block (m = 0.40 kg) on the end of a string with a radius of 0.7 meters makes 9 rotations in 20.7 seconds when twirled. a)What is the block's tangential (linear) speed? b)What is the block's angular speed?

asked by phys 220
15. ## physics

a solid X, insoluble in water, weighs 180g in air and 150g in water. what is the relative density of the solid X? it is the physics question.

16. ## physics

The handle of a 27kg lawnmower makes a 36∘ angle with the horizontal. If the coefficient of friction between lawnmower and ground is 0.66, what magnitude of force, applied in the direction of the handle, is required to push the mower at constant

17. ## Life orientation

Show the link between itrapersonal conflict and initiating relationship

18. ## Physics

The figure below shows an initially stationary block of mass m on a floor. A force of magnitude F = 0.550mg is then applied at upward angle = 19°. (a) What is the magnitude of the acceleration of the block across the floor if the friction coefficients are

19. ## Business Math

Lance Lopes went to his bank to find out how long it will take for \$1,700 to amount to \$2,900 at 10% simple interest. Can you solve Lance’s problem?

20. ## phyic

Calculate the gravitational force between the Sun and Jupiter. The mass of the Sun is 1.99×1030 kg. The mass of Jupiter is 19000×1023 kg. The distance between them is 77.8×1010 m.

21. ## Physics 2

Using the diagram to the left, rank each of the given paths on the basis of the change in electric potential. Rank the largest-magnitude positive change (increase in electric potential) as largest and the largest-magnitude negative change (decrease in

22. ## math

All prime numbers less than ten are arranged in descending order to form a Number. (a) Write down the number formed 2, 3, 5, 7 (b) State the total value of the second digit in the number formed in (a) above

23. ## Art

How has colantorio used visual composition to communicate the glory of war in Alexander the Great and His Conquest of Asia A colantorio shows exuberant soldiers celebrating their victory B. colantorio shows powerful Alexander slaying his enemy C.

24. ## Statistics

Anger and Snap Judgments Read the article entitled “Anger Can Cause Snap Judgments” and answer the following questions. ANGER CAN CAUSE SNAP JUDGMENTS Anger can make a normally unbiased person act with prejudice, according to a forthcoming study in the

25. ## math

The radius of a circular field is 31.5 meters.what is its circumference ?

26. ## Physics

A group of students observes that a wooden block (m = 0.40 kg) on the end of a string with a radius of 0.7 meters makes 9 rotations in 20.7 seconds when twirled.

27. ## Trig/Precalc

The system of equations: |z-2-2i|=sqrt(23), |z-8-5i|=sqrt(38) has two solutions z_1 and z_2 in complex numbers. Find (z_1+z_2)/2. My first instinct on this problem was to square each equation given that the square of the magnitude of a complex number is

28. ## physics

A group of students observes that a wooden block (m = 0.40 kg) on the end of a string with a radius of 0.7 meters makes 5 rotations in 20.7 seconds when twirled.

29. ## Algebra 1

The attendances at a high school basketball games seems to be affected by the success of the team. Look at the table and decide what function would represent the data shown. attendance 150 200 250 300 350 wins 2 4 6 8 10 a) a=2(3)^g b) a=-25g+100 c)

30. ## physics

A skier of mass m = 55kg glides down a slope at angle theta = 32∘, as shown in the figure below. The snow is so slippery that you can neglect friction. Find the skier's acceleration. Express your answer using two significant figures. Find the force the

31. ## chemistry

Calculate the change in enthalpy produced by dissolving 14.3 g of NaOH in 65.0 g of water if the temperature increases 49.1°C and the specific heat of water is 4.18 J/g°C I believe you multiply 4.18, 65.0, and 49.1. Am I correct

32. ## Physics

Angelito wanted to lose weight by dieting and exercising. One day, he only had a loaf of bread with an energy content of 2.50 x 10^5 J for his breakfast. To exercise, he lifted a 28.34kg to a height of 0.5m. How many times must he lift and lower the

asked by Jay K Dee
33. ## math

When a child breaks open her piggy bank, she finds a total of 76 coins, consisting of nickels, dimes, and quarters. The total value of the coins is \$9. If the nickels were dimes, and the dimes were nickels, the value of the coins would be \$8. How many

34. ## Criminal Justice/Judicial System

Studies indicate that __________ are overrepresented in the jail population. A. Whites B. Hispanics C. African-Americans D. Asians I Think it's B, but not sure.

35. ## I am so lost

The freezing point of pure cyclohexane is 6.60°C and the freezing point depression constant is 20.00°C/m. The freezing point of a solution containing 0.161 g of an unknown nonelectrolyte solute and 5.818 g of cyclohexane was 3.98°C. What is the molar

36. ## physics

Children sled down a 44m -long hill inclined at 27∘ . At the bottom, the slope levels out. If the coefficient of friction is 0.11, how far do the children slide on the level ground? Express your answer using two significant figures.

37. ## math

Evaluate 6log2^3 √64+ 10log3^5 √243

38. ## physics

A water (H2O) molecule consists of two hydrogen atoms and one oxygen atom. The oxygen atom is located at the origin. One hydrogen atom is between the positive x-axis and positive y-axis and the other hydrogen atom is between the negative x-axis and the

39. ## math

the local lions club sold raffle tickets for a new golf caqrt. the sales for each week are given below. if more tha 250 tickets are sold, then the lions club raised enough for the golf cart. use the inequality t>250, where t representrs the number of

40. ## algebra

how many tiles 10cm by 25cm on each side is needed for a bathroom 8m by 10m? I need help on how to solve it... I learned how to do this in 8th grade but I'm now in 10th and I forgot how to do it. I'm preparing for the highschool exit exam and I need to do

41. ## Business Math

He took out a \$100.00 loan payable in two weeks at \$105.50. What is the percent of interest paid on this loan?

42. ## science

In an experiment to determine the speed of sound, two observers, A and B, were stationed 5.0 km apart. Each was equipped with a gun and a stopwatch. Observer A heard the report of B's gun 15.5 s after seeing it's flash. Later, A fired his gun and B heard

43. ## physics

A hockey puck of mass m = 120 g is attached to a string that passes through a hole in the center of a table, as shown in the figure below. The hockey puck moves in a circle of radius r = 0.50 m. Tied to the other end of the string, and hanging vertically

44. ## physics

Two objects, with masses m1 and m2, are originally a distance r apart. The gravitational force between them has a magnitude F. The second object has its mass changed to 4m2, and the distance is changed to r/7. What is the ratio between the magnitude of the

46. ## Physics

One 3.30 kg paint bucket is hanging by a massless cord from another 3.30 kg paint bucket, also hanging by a massless cord, as shown in figure below. If the two buckets are pulled upward with an acceleration of 1.57 m/s by the upper cord, calculate the

47. ## math

Jamar is trying to fit his encyclopedia on a shelf. Each book is 2 1/4 inch thick. The shelf is 2 1/4 feet wide. How many books will Jamar be able to fit

48. ## physics

Starting from rest, a skier slides 100 m down a 28 ∘ slope. How much longer does the run take if the coefficient of kinetic friction is 0.17 instead of 0? Express your answer using two significant figures.

49. ## health

An HMO with 50,000 members had 13,024 inpatient service days for last month. What formula would you use to determine bed days per 1,000, and what was this HMO's rate for last month?

50. ## physics

An unknown object with mass M slides on a smooth frictionless surface with a speed of 35.0 m/s along the x-axis. Suddenly it explodes into two pieces, P and Q, which move in different directions as shown in the figure below. Determine the final velocity of

51. ## chemistry

If a reaction has a percentage yield of 83.0%, what mass of methane can be obtained from 1150 g of carbon? 2 C(s) + 2 H2O(l) CH4(g) + CO2(g) *Answer in grams*

52. ## ALGEBRA

What is the rule for the function shown in the table? x -1, 0, 1, 2 y -2, 1, 4, 7 a. y=1/3x+1 b. y=3x+1 c. y=1/3x d. y=1/2+1****** Please help

53. ## science

A girl drops a stone into a mineshaft 122.5m deep. how soon after she throws does she here the striking of the stone at the bottom of the shaft?

54. ## science

A girl drops a stone into a mine shaft 122.5m deep. How soon after she drops it does she here the sound of it striking the bottom of the shaft?

55. ## Pre-Calculus

he amount M (in billion of dollars) of mortgage debt outstanding in the US from 1990 to 2001 can be approximated by the function M(t)= 29.9t^2 + 3892 where t=0 represents 1990. Rewrite the function so that t=0 represents 2000.

56. ## physics

A police officer investigating an accident estimates that a moving car hit a stationary car at 24km/h . If the moving car left skid marks 45m long, and if the coefficient of kinetic friction is 0.71, what was the initial speed of the moving car? Express

57. ## Algebra

Which is NOT true about the following table. X. 1, 2, 3, 4 Y 1, 4, 9, 16 A. It shows a linear function******** B. x increases by 1 each time C. The rate of change is not constant D. Y increases by a different value each time Write a quadratic function rule

58. ## math

The owner of a home decorating shop wants to mix dried rose petals selling for \$6 per pound, dried lavender selling for \$4 per pound, and buckwheat hulls selling for \$3 per pound to get 10 pounds of a mixture that would sell for \$3.70 per pound. She wants

59. ## chemistry

A 100.0 ml aqeuous solution that contains 0.50 g of hemoglobin has an osmotic pressure of 0.00178 atm. What is the molar mass of hemoglobin?

60. ## Spanish

I need a sentence in the past and future tense using the following. tener éxito,tener ganas de,tener celos,tener la culpa,tener en cuenta,tener suerte,tener confianza, tener sed, tener hambre

61. ## MAth

Jim bought a pen and a calculator. He paid the cashier \$50 and received \$20.45 change. If the pen cost \$4.50, how much did the calculator cost?

62. ## Physics

A battery has an emf of 15.0 V. The terminal voltage of the battery is 11.2 V when it is delivering 26.0 W of power to an external load resistor R. (a) What is the value of R? (b) What is the internal resistance of the battery?

63. ## GEOMETRY

What is the value of W? A triangle with hypotenuse W and with a leg with length 7sqrt3 and angles measuring 90 degrees and 30 degrees. 7 3.5 7 sqrt3 14

64. ## Physics

A Gun of Mass 3.5kg fires a bullet at 320m/s. If the gun recoils with a speed of 24m/s, calculate the mass of the bullet.

65. ## physics

a student wants to determine the coefficient of static friction and kinetic friction between a box and a plank by gradually raising one end of the plank. when the angle of inclination with the horizontal reaches 28.0, the box starts to slip and slide 2.53

66. ## chemistry

A freezing point depression experiment was conducted using cyclohexane as the solvent. The freezing point of pure cyclohexane is 6.60°C and the freezing point depression constant is 20.00°C/m. The freezing point of a solution containing 0.135 g of an

67. ## College Algebra

Write an equation that has the given solutions. 0, 2, and 9

68. ## Chemistry

Calculate the number of grams of propane (C3H8) consumed if 17.7 g of water is produced according to the reaction: C3H8(g)+5O2(g)=3CO2(g)+4H2O(g)

69. ## calculus

hi! just needed help on an FRQ for ap calculus ab. let me know if you have any questions for me. I'm just really confused as far as what I am meant to do. If you could walk me through it that would be amazing. THANKS!! A population is modeled by a function

70. ## Interpersonal communication

Before communicating, the sender must encode the idea that he or she wants to communicate, or put it into some form or code that he or she hopes the other person can understand. True or False

71. ## statistics

From Lab 3, Problem 2 2. The data set magnet is from an experiment to see the effect of voltage and number of turns on the magnetic force of an electromagnet. The experimenters expected to see a limit to which the number of turns could increase the force.

72. ## Chemistry

How much potassium chloride in grams is needed to prepare 1500ml solution of 3% kcl solution? This is my answer: 3x1500=4500 4500÷100=45 Answer is 45gm

73. ## proper mathematics

Linda borrows 4000 from his father to go on a trip to Kenya.he will have to pay the money back in 10 years time.his father will charge him a simple interest rate of 4% p.a.how much will Linda have to repay after 10 years?

asked by perseverance smith
74. ## Science

In electromagnetic waves, frequency is inversely proportional to A. Amplitude. B. Wave speed. C. Wavelength. D. ReflectioN. Is the answer C? Thank you

75. ## physics

A woman with mass of 63 kg stands at the rim of a horizontal table having a moment of inertia of 520 kg m2 and a radius of 1.5 m. The turntable is initially at rest and is free to rotate about a frictionless, vertical axis through its center. The woman

76. ## anthropology

Let's consider the practice known as female genital mutilation that is very common in many African and Middle Eastern cultures. Since these are performed outside of the U.S., our laws don't apply, but there are many people who argue that we should impose

77. ## Algebra 1

Which expression is the factored equivalent of 3x^2-4x+1? A. (3x-1)(x-1) B. (3x-1)(x+1) C. (3x+1)(x-1) D. (3x+1)(x+1) When I factor it, I keep getting D. But I know the answer is A. So this must be a common mistake students make. What am I doing wrong?

78. ## anthropology

I can't found this in the book. Please help me. Can an anthropologist be apolitical, a-contextual, a-cultural?

79. ## Criminal Justice/Judicial Process

Which of the following is not a key reason for which cases are treated differently from one another? A. Celebrated cases B. Private versus publicly retained counsel C. Offender's sex D. Seriousness of the offense I think it's C, but not sure.

80. ## math

I'm just having trouble trying to see the independent and dependant variables. I have to determine whether the following are functions: The relation between distance and time if someone walks 5km/h. I think distance would be the independent variable

81. ## physics

The large blade of a helicopter is rotating in a horizontal circle. The length of the blade is 7.0 m, measured from its tip to the center of the circle. Find the ratio of the centripetal acceleration at the end of the blade to that which exists at a point

82. ## Socials

I am doing a slavery project and I chose "Early and Forced Marriage" as my form of slavery. There is one section of the project that I do not get how to properly search for information and it is "can you find what kind of protection they(the country

83. ## physics

Two forces of the same magnitude act at a point.the square of their resultant is 3 times the product of their magnitudes.the angle between them is?

84. ## chemistry

What will be the final temperature of 650 g of water initially at 5.5°C if it is heated by burning 7.5 g of carbon to carbon dioxide. The molar heat of reaction is -393.5 kJ/mol. I do not understand how to do this question

85. ## Physics

Express the angular velocity of 36 rpm (revolutions per minute) in units of radians per second (rad/s).

asked by phys 220
86. ## Science

An elastic cord of elastic constant k and length L is hung from point A having a massless block at the other end. A smooth ring of mass M falls from point A. What is the maximum elongation of cord?

87. ## physics

A charge of +355 μC is fixed at the center of a square that is 0.64 m on a side. How much work is done by the electric force as a charge of +7.9 μC is moved from one corner of the square to any other empty corner?

88. ## chemistry

describe the predominant forces that exist between molecules of the noble gases. Arrange the noble gases in a predicted order of increasing boiling point (lowest first) and explain the reason for the order

89. ## english..

Can someone help me change up the words? A positively charged drum has the image drawn on it with a laser. The areas touched by light become negatively charged. Positively charged toner particles are attracted to the negative areas on the drum. The drum

90. ## science

What effects or potential effects do technologically based communication modalities between patients and health carer providers and between health care providers only have on health care cost

91. ## Economics

Why are countries that let people respond to the inborn profit motive better off than those countries that do not?

92. ## Calculus

Integrate Cos^7(2x) Explanation would be helpful

93. ## Accelerated Science

Match each situation with the correct method of heat transfer: a. radiation b. conduction c. convection __A_ 1) The inside of a car gets very hot when that car is parked on a parking lot in the middle of August. __A_ 2) During the winter when the furnace

94. ## Pre-calculus

Let z and w be complex numbers such that |2z-2|=25, |z+2w|=5, and |z+w|=2. Find |z|. I first squared both equations and expressed the square of the magnitudes in terms of the complex numbers and its conjugates. Next, I summed the equations together and

95. ## Chemistry

Posted by Cyndy on Sunday, February 15, 2015 at 6:45pm. How many grams of ammonium chloride are needed to raise the ammonia level 5 ppm in a 300 gallon system? Now, I have worked the problem so many times I have confused myself I think. I keep getting 2

96. ## math

the length and breadth of the room were measured and area calculated as 600sq.m. (l+B=50) later found the meter rod that had used as an error 5cm i.e actual length of the rod ws 95cm instead of 100cm. find the correct area of the room

97. ## chemistry - dilution factor

I have 4 ml of eluent from SPE and I brought the volume up to 5 ml using the solvent. The eluent was ran in UV for Quant analysis. Is the dilution factor 0.8 because it would be "4 in 5"?

98. ## english

WRITE FOR E XAMPLE "THE NIGHT IS STARRY AND THE STAR ARE BLUE AND SHIVERIN THE DISTANCE WHAT ANS

asked by RAJU JETHI
99. ## Precalc

A corpse was discovered in a motel room at midnight and uts temperature was 82°F. The temperature dropped to 80.5°F two hours later. Given k is a constant for the object in question, S is the surrounding temperature, t represents the time and theta(of

100. ## Science

Ball A Momentum Before collision is 3 kg m/s. Ball B Momentum Before Collision is 2 kg m/s. Total Momentum of Both Balls After Collision is 6 kg m/s Ball A and Ball B are rolled so that they will collide. Does the data in the table above demonstrate the

101. ## math

The perimeter of a rectangular blanket is 18 feet.What could be it's length and width?

102. ## transcription

ABDOMEN: Soft without masses

103. ## Math

Lana travelled 50.40 kilometers in 84 minutes. Write an equation that can be used to express the relationship between the total kilometers travelled(t) and the minutes(m) it took. The answer I got was 1.66666... By dividing 50.4 from 84. My friend told me

104. ## chemistry

A student is performing an experiment to find the density of water. She obtains a 100ml beaker, which weighs 53.257 grams, and she fills it with 60 mL of water. The temperature of the water is 25.5 degrees celsius (room temperature). Again the student

105. ## Math

If someone takes out a Reverse Mortgage of \$200,000 at 6.8% Interest how much will they owe in five years time and ten years time

106. ## Math

The following set of numbers respresents the average weekly scores of 9 preschoolers on a verbal aggression scale. 19.1, 18.9, 33.5, 18.7, 28.1, 31.5, 20.3, 30.1, 17.9 Consider this to be the entire population of scores. What is the standard deviation? I

107. ## Chemistry

Why is the slowest elementary step "the rate determining step"?

108. ## math

the track cpach records the number of laps the team runs each day fr a week in the table below. if the team rus at most 10 laps each day, then they have to practice saturday. use the inequalty l is less than of equal to where l represents the number of

109. ## Algebra

Find two numbers with a sum of -8 and a difference of 4. Let x be the greater number and y be the lesser number. Thanks you

asked by Struggling mom
110. ## maths(urgent answer pls)

Show that the series 1 + 2x/5 + 3x^2/25 + 4x^3/125 + ....is convergent if -5

111. ## Calculas

Integrate: Cos^7(2x) Explanation would be helpful

112. ## math

integrate Cos^7(2x)

113. ## math

the cost of admission for adults is \$12 and children under 12 are charged \$8.00. If 20% of the total ticket sales were for children how much more money could they have made if all the tickets had been sold to adults?

114. ## Chemistry

Are halogens and non-metals metal or non-metals? I think they're both non-metals

115. ## Physics

Calculate the acceleration of a plane when it changes its speed from 0m/s to 250m/s in 12 seconds

116. ## costs

if 4 pencils sell for .59 cents how much will 25 pencils cost?

117. ## Values

How can I start a good conclusion about true beauty and goodness?

118. ## maths

two straight poles length 80m, 50 m vertically with a distance 40m. a rope is connected their tops. find the length of the rope?

119. ## maths

If the length of the fence of a trapezium shaped field ABCD is 130m and side is perpendicular to each of the parallel side AD and BC.if BC=54m ,CD=19m and AD=42m, find the area of the field.

120. ## I am so lost

The freezing point of pure cyclohexane is 6.60°C and the freezing point depression constant is 20.00°C/m. The freezing point of a solution containing 0.161 g of an unknown nonelectrolyte solute and 5.818 g of cyclohexane was 3.98°C. What is the molar

121. ## calculus

s= [b]*[d]+64t-16t^2 what is the greatest height above the ground the rock will go

122. ## math

Given that sin (x +30)° = cos 2x° for 0°, 0° ≤ x ≤ 90° Find the value x. Hence find the value of cos^2 3x°.

123. ## math(urgent answer pls)

Show that the series 1 + 2x/5 + 3x^2/25 + 4x^3/125 + ....is convergent if -5

124. ## Pre calculus

A tugboat is traveling at 30 miles per hour at a compass heading of 38 degrees. The current is from the direction of 125 degrees moving at 7 mph. Find the resultant speed and the direction of the boat. I understand the concept and that I must use the law

125. ## SS

What might be the impact on a country when the oldest people are in their 40s?

126. ## Statistics

Can someone please separate this terms by categorical variable and numerical variable: Region Population Growth Rate Adult Literacy Measles Immunity Male Life expectancy Female life expectancy Male Healthy Average Life Expectancy Female Healthy Average

127. ## Math

X. 0, 1, 2, 3 Y. -6, -5, -2, 3 A. Y=x-6 B. y = x-4 C. Y =x^2-3 *********** D. Y = x^2-6 Write a quadratic function rule for the given table X. -1 0 1 2 Y. 5 4 5 8 A. Y = x+4 B. Y=x^2+4 ********* C. Y = x^2+6 D. Y = x+6 Please help I'm confused

128. ## Math

A 6 story building has stairs between equally spaced doors. How many times higher is the climb from the first to the sixth floor than the climb from the first to the third floor?

129. ## English

I need help finding examples of hopelessness and hope in "A Raisin in the Sun" by Lorraine Hansberry in Act 1

130. ## Algebra

Oregon, 21 4 %per month

131. ## math

what is 1 plus 1

132. ## math

m-n divided by 4. use m =5 and n = 8. please help. ty

133. ## ENGLISH LANGUAGE ARTS

DO YOU HAVE A POEM CALLED MOTHER TO DAUGHTER AND IT TELLS WHAT THE EXTENDED METAPHOR IS?

134. ## Algebra

a^2 * b equals what