Emily

Popular questions and responses by Emily
1. Honors Chemistry

"How many grams of NH3 can be produced from the reaction of 28 g of N2 and 25 g of H2? N2 + 3H2 ---> 2NH3 ==> 28 g N2 x (1 mol N2/14.0 g N2) x (2 mol NH3/1 mol N2) x ( 17.0 g NH3/ 1 mol NH3) = 68 g NH3 25 g H2 x ( 1mol H2/2.0 g H2) x (2 mol NH3/3 mol H2) x

2. Physics

Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting on the body?

3. Math

A bag contains 6 red marbles, 3 white marbles, and 7 blue marbles. You pick a marble without looking. Find the probability of drawing a white marble. Can someone please explain how I would work this out?

4. Chemistry

A sample of argon gas at STP occupies 56.2 liters. Find the number of moles of argon and the mass in the sample

5. Calculus

A solid is formed by adjoining two hemispheres to the ends of a right circular cylinder. An industrial tank of this shape must have a volume of 1600 cubic feet. The hemispherical ends cost twice as much per square foot of surface area as the sides. Find

6. Math

An auditorium has 50 rows of seats. The first row has 20 seats, the second row has 21, the third row has 22 seats, and so on, each row having one more seat than the previous row. How many seats are there all together? a. write 2 different expressions for

7. Chemistry

Write a balanced net ionic equation (include physical states) for the following reaction: Fe(NO3)3(aq) + LiOH(aq) → LiNO3(aq) + Fe(OH)3(s)

8. Math

Mike had x pieces of candy. He kept pieces 15 for himself and equally divided the remaining pieces among his 6 friends. How many pieces of candy did each of his friends get?

9. Physics

Two rugby players are running towards each other. They are 37 m apart. If one is accelerating from rest at 0.5 m/s^2 and the other was already moving at 3.1 m/s and maintains her speed, a)how long before they crunch together? b)How fast was the

10. Science

Calculate the quantity of energy required to change 3.00 mol of liquid water to steam at 100°C. The molar heat of vaporization of water is 40.6 kj/mol

11. math

The busy Mother pours herself a coffee into a paper cup before making her way to the amusement park. The coffee temperature is 35 C when the cup is placed on the kitchen counter. The Mother needs to tend to her son and her coffee is forgotten. When the

12. Geometry probability

Betty picks 4 random marbles from a bowl containing 3 white, 4 yellow, and 5 blue marbles. The probability that exactly 1 of the 4 marbles drawn is blue is _____ (I know that the probability is 5/12 and that simplifies to 0.4166 but that is not one of the

13. Math

A son is 8 years old. His father is five times as old. How old was the father when his son was born?

14. Life sciences, Business studies,Maths lit and CAT

With Life sciences, Business studies,Maths lit and CAT, what can I study after matric? Which career field should I follow?

15. Math

Several games were played between two basketball teams: the Tigers and the Bears. The Tigers won the first game by two points. A total of 90 points was scored during the game. How many points did each team score?

16. Math

The 10th term of an arithmetic series is 34, and the sum of the first 20 terms is 710. Determine the 25th term.

17. algebra

What is B if the graph of the equation 3x=By+2 is perpendicular to the graph of 3y=-2x+4

18. Science

A tube at both ends has a length of 30 m A. What is the length of a tube open on one end tha has the same fundamental frequency B what is the frequency

19. chemistry

The formation constant* of [M(CN)4]2– is 7.70 × 1016, where M is a generic metal. A 0.170-mole quantity of M(NO3)2 is added to a liter of 1.040 M NaCN solution. What is the concentration of M2 ions at equilibrium?

20. Math

1) There were a total of 840 guests at a wedding dinner. 60% of them were adults, and the rest were children. Some boys left before the dessert was served. As a result, the percentage of adults increased to 70%. How many boys left before the dessert was

21. Calc

A baseball is thrown upwards from a height of 2 meters with an initial velocity of 10 meters per second. Use the fact that -9.8 meters per second squared is constant acceleration due to gravity to answer the following: The maximum height of the ball The

22. Calc

A buoy oscillates in simple harmonic motion as waves go by. The buoy moves a total of 3.5 feet from its low point to its high point and it returns to its high point every 10 seconds. What is the equation that describes this motion if it reaches its high

23. Calculus

A pencil cup with a capacity of 25π in.3 is to be constructed in the shape of a right circular cylinder with an open top. If the material for the side costs 5/8 of the cost of the material for the base, what dimensions should the cup have to minimize the

24. World History

Why did rogue states become more prominent following the Soviet Union’s collapse? I know what a rogue state is but I don't know why it is involved with the Soviet Union and their collapse. I also know that it has something to do with the Cold War. Can

25. Math (geometry)

A diagonal of one cube is 2 cm. A diagonal of another cube is 4*sqrt3 cm. The larger cube has volume 64 cubic cm. Find the volume of the smaller cube. --------------------------------------------------------------------------------------------------- There

26. Science

After 2 turning fork are simultanesly struck, one hears 4 beats per second. If the frequency of one tuning fork is 480 Hz find the possible frequencies of the other tuning fork

27. Physics

Determine the stopping distances for an automobile with an initial speed of 95km/h and human reaction time of 1.0s: (a) for an acceleration a= -5.2m/s^2 (b) for a= -6.7m/s^2

28. math

It is a beautiful sunny day at the fair. The U.V. index for this day is 8, or high, so sunscreen is a must for all the young folk. The effectiveness of sunscreen is indicated by the sunscreen protection factor (SPF). The higher the SPF number the fewer

29. physics!

In a scene in an action movie, a stuntman jumps from the top of one building to the top of another building 4.0m away. After a running start, he leaps at an angle of 15 degrees with respect to the flat foor while traveling at a speed of 5.0 m/s. will he

30. math

Find all the values of x in the interval [0,2π] that satisfy the equation: 8sin(2x)=8cos(x)

31. Calculus

Find the slope and y-intercept of the line through the point (6,2) that cuts off the least area from the first quadrant.

32. biology

which of the following statements about enzymes is NOT true? A. enzymes work best at a specified pH B. all enzymes have the same shape as their substrates. C. enzymes are proteins D. the shape of an enzyme allows it to do its job. im pretty sure its A. Am

33. Physics

A rotating uniform-density disk of radius 0.6 m is mounted in the vertical plane. The axle is held up by supports that are not shown, and the disk is free to rotate on the nearly frictionless axle. The disk has mass 5.8 kg. A lump of clay with mass 0.5 kg

34. Chemistry

Consider the following hypothetical aqueous reaction: A (aq)-->B(aq)}. A flask is charged with 0.065 (mole) of A in a total volume of 100.0 (mL}. The following data are collected: Time (min) 0 10 20 30 40 Moles of A .065 .051 .042 .035 .031 Calculate the

35. Math

Determine the equation of the parabola with roots 2+sqrt(3) and 2-sqrt(3), and passing through the point (2,5).

36. ap chem

consider the molecules PF3 and PF5. b]is the PF3 molecule polar or is it nonpolar. explain C] on the basis of bonding principles, predict whether each of the following compounds exists. In each case explain your prediction. (i) NF5 (ii) AsF5 2. explain why

37. math

If the measure of angle 1 is 123 degrees, find the measure of

38. Chemistry (PLZ HELP)

Hydrazine, N2H4(aq), is used in the preparation of polymers, pharmaceuticals and rocket fuel. Hydrazine has alkaline properties similar to ammonia and will act as a weak base. Given that a 100 mL sample of 0.10 mol/L hydrazine solution has a pH of 10.55 at

39. Earth space science

During which step in the Can Crush Lab did water vapor condense inside the can? A. The can was filled nearly to the top with water. B. The can was placed on the hot stove burner for several minutes. C. The can was removed from the hot stove burner. D. The

40. French

Is the word 'maths' masculine or feminine?

41. Ap Chem

explain each of the following observations using principles of atomic stucture and/or bonding. a] potassium has a lower first-ionization engergy than lithium. b] the ionic radius of N3- is larger than that of O2-. c] a calcium atom is larger than a zinc

42. Chemistry

How would the following affect the calculated value of neutralizing power of antacid (make it higher, lower or no effect)? [The lab uses the back titration technique] 1) The solution mixture of reacted antacid and excess of HCl spattered out the flask

43. Chemistry

Which pair of compounds will form a solution? A) Benzene (C6H6) and Hexane (C6H14) B) Na2SO4 and Benzene C) NaCl and Hexane

44. Calc BC

Figure out the 35th derivative for xsinx. You have to do a few derivatives by hand to figure our a pattern and then predict the 35th one

45. cochise

How many kilocal are required to increase the temperature of 15.6 g of iron from 122 °C to 355 °C? The specific heat of iron is 0.450 J/g °C

46. Statistics

A gambler offers to let you play the following game: he will roll two (fair) dice. If the sum of the two dice is 7, you will lose \$8. If the sum of the two dice is 2, you will lose \$7. For any other roll, you will win \$4. What is the expected value of this

47. math

6. The half-life of a certain radioactive material is 32 days. An initial amount of the material has a mass of 361 kg. Write an exponential function that models the decay of this material. Find how much radioactive material remains after 5 days. Round your

48. English grammar

In the following sentence identify the function of the infinitive (phrase). Is it too expensive to travel to Europe? My list of answers contains: Adverb, subject, direct object, adjective, object of preposition, and predicate noun. I chose predicate noun.

49. chemistry

How many moles of Na2CO3 would be needed to react with 750 mL of 0.250 M H2SO4 solution?

50. chemistry

Given that the specific heat capacities of ice and steam are 2.06 J/g°C and 2.03 J/g°C, the molar heats of fusion and vaporization for water are 6.02 kJ/mol and 40.6 kJ/mol, respectively, and the specific heat capacity of water is 4.18 J/g°C, calculate

51. Math

Suppose the polynomial f(x) has the following end behavior: as x→∞, f(x)→−∞, and as x→−∞, f(x)→−∞. Which of the following polynomials could represent f(x)? There may be more than one correct answer. Select all correct answers. a.

52. Science

Study the scenario. An object is at rest. At five seconds, someone comes over and pushes the object with a force of 3 N to the right. Which of the following choices describes the force needed to keep the object in static equilibrium? a. A force of 3 N to

53. arithmetic geometric

Determine whether each sequence is arithmetic geometric or neither if the sequence is arithmetic give the common difference if geometric give the common ratio 1. 6,18,54,162, 2. 4,10,16,22 3. 1,1,2,3,5,8 4. 625,125,25,5 5. 5,8,13,21,34

54. Math

It is a beautiful sunny day at the fair. The U.V. index for this day is 8 or higher so sunscreen is a must. The effectiveness of sunscreen is indicated by the sunscreen protection factor (SPF). The higher the SPF number the less U.V. rays can penetrate to

55. Math

Find the missing length. Round to the nearest tenth of necessary. It is a right triangle with side a being 8 ft and side b being 21ft what is the length of the 3rd side? A 441 B 22.5 C 64 D 19.4* Am I right and please explain I am a little confused.

56. math

Show that a function f(n)= 2n^3+n^2+6n+3 always produces a number that is divisible by an odd number greater than 1, for any natural number, n. 2n^3+n^2+6n+3 = n^2(2n+1) + 3(2n+1) = (2n+1)(n^2 + 3) what's next?

57. Physics

The place kicker on a football team kicks a ball from ground level with an initial speed of 8.30 m/s at an angle of 19.0° above the horizontal. How long is the ball in the air before it lands on the ground again? You may neglect air resistance.

58. American Government

Why do presidents prefer federal judges who tend to agree with their views?

59. chemistry

A major component of gasoline is octane C8H18. When octane is burned in air, it chemically reacts with oxygen gas O2 to produce carbon dioxide CO2 and water H2O. What mass of octane is consumed by the reaction of 8.8g of oxygen gas? Round your answer to 2

60. Math

Mr.Adams had a coin collection including only nickels, dimes, and quarters He had twice as many dimes as nickels and half as many quarters as he had nickels. If the total face value of his collection was \$300.00, how many quarters did the collection

61. English Grammar - Clauses

The following sentence contains _____. We like him as much as them. an adjective clause a noun clause an elliptical clause no subordinate clause I think "as much as them" is an adverb clause but since it's not an option, I'd choose "no subordinate clause."

62. math- plz help

The denominator of a fraction is greater than its numerator by 9. If 7 is subtracted from both its numerator and denominator, the new fraction equals 2/3. What is the original fraction?

63. General Chemistry (Chem101)

A chemist mixes two liquids A and B to form a homogeneous mixture. The densities of the liquids are 2.0514 g/mL for A and 2.6678 g/mL for B. When she drops a small object into the mixture, she finds that the object becomes suspended in the liquid; that is,

64. Chemistry

net ionic equation of Na2CO3+2HC2H3O2-->CO2+h2o+2Na2H3O2

65. Geometry

Find the value of the variable and VW if V is between U and W. UV=2,VW= 3x, UW=29 UV = r, VW = 6r, UW =42 UV = 4p - 3, VW = 5p, UW =15 UV = 3c+29, VW = -2c-4, UW = -4c Need a site to explain how to do these. Teacher not clear on explaining.

66. Physics (check)

A merchant in Katmandu sells you a solid gold 1-kg statue for a very reasonable price. When you get home, you wonder whether or not you got a bargain, so you lower the statue into a measuring cup and measure its volume. What volume will verify that it's

A lighthouse with a rotating beam is located 500m south of a coastal cliff that runs west to east a) determine a relation for the distance from the lighthouse to the point the light strikes the cliff in terms of the angle of rotation x b) determine an

68. Algebra

A rectangular pool has a perimeter of 142 feet. The length is 25 feet longer than the width. Find the length and width of the pool.

69. Math

A farmer wishes to enclose a rectangular region with 196 meters of fencing in such a way that the length is twice the width and that the region is divided along its length into two equal parts. What is the length and width in meters?

70. physics

Piston 1 has a diameter of 0.643 cm. Piston 2 has a diameter of 4.59 cm. In the absence of friction, determine the force required on piston 1 necessary to support an object, m, with weight 1151 N. (Neglect the height difference between the bottom of the

71. science

A simple model for a person running a 100m race is to assume the sprinter runs with constant acceleration until reaching top speed, and then maintains that speed through the finish line. If a sprinter reaches their top speed of 11.2ms-1 in 2.15s, what will

72. Calculus I

Sketch the graph of f by hand and use your sketch to find the absolute and local maximum and minimum values of f. 18. f(x) = 1/x , 1 < x < 3 I can graph it just fine, but for my answer I got that the function has none of the above. Is this correct?

73. Chemistry

What will be the freezing point of a solution made by dissolving 5.25 g of naphthalene (C10H8) in 100.0 g benzene (C6H6?). The normal freezing point of benzene is 5.5°C and K f (benzene) is 5.12°C / m.

74. Physics

The brakes of a truck cause it to slow down by applying a retarding force of 8740 N to the truck over a distance of 1130 m. What is the work done by this force on the truck?

75. Math

The point (-8,3) lies on the terminal arm of angle theta in standard position. Determine the primary trigonometric ratios for angle theta and calculate the value of theta to the nearest degree. Only the sine ratio was positive, and when I used that to

76. Chemistry

Hydrogen cyanide is a highly poisonous, volatile liquid. It can be prepared by the following reaction. CH4(g) + NH3(g) → HCN(g) + 3 H2(g) What is the heat of reaction at constant pressure? Use the following thermochemical equations. N2(g) + 3 H2(g) → 2

77. Math

Given any right triangle with an acute angle theta, a) Explain why csc theta is always greater than or equal to 1 b) Explain why cos theta is always less than or equal to 1

78. math

The measure of an interior angle of a regular polygon is 135 degrees. Find the number of sides in the polygon. This is what I tried: 180(x-2)=135 [Interior Angle Sum Theorem] x-2=.75 x=2.75 That can't be right though. Help? Not sure about your formula.

79. Math

Lucy sang 4 songs. Every song was 5/8 minutes long. For how much time did she sing in total? Write your answer in simplest form. I think that you should do 5/8 x 4. Which equals 2.5. But if we need it in simplest form, that would be 5/2 or 2 and 1/2. Is

80. Algebra 1

Josh and Greg leave from the same place and travel the same route. Josh travels 2 hours and stops. Greg travels 5 hours at double Josh's rate. After five hours they are 256 miles apart. Find the rate and distance of each.

81. physics

An aluminum block absorbs 1.0 x 104 J of energy from the Sun when its temperature increases by 5.0 °C. What is the mass of the block? the specific heat capacity of aluminum is 920

82. math

Show that a function f(n)= 2n^3+n^2+6n+3 always produces a number that is divisible by an odd number greater than 1, for any natural number, n.

83. physics

15. During the opening kickoff of a college football game, the kicker kicks a football with an initial velocity of 27.5 m/s at an angle of 41° above horizontal. I. What is the time of flight for the ball? II. How far does it travel before hitting the

84. physics

A fighter jet is flying at Mach 3.2 in air of temperature 2 degrees C. What is the planes speed? I really don't understand how to do this question. I'd appreciate your help!

85. math

Which set of ordered pairs has point symmetry with respect to the origin (0, 0)? (9, 2), (-9, 2) (9, 2), (-9, -2) (9, 2), (9, -2) (9, 2), (2, 9)

86. Calc

Find the particular solution that satisfies the differential equation and the initial condition. f '(s) = 10s − 4s3, f(3) = 7 & f ''(x) = 6, f '(2) = 14, f(2) = 19

87. math

A billboard is 4.0 meters by 2.5 meters. A scale diagram of the billboard must fit in a space that is 15 centimeters by 12 centimeters. Write a reasonable scale for the scale diagram.

88. Biology

A patient has type AB blood. If they received a transfusion of type B blood, predict and explain what would happen

This question is based on the following four sentences. 1. Netta and Jim argued over their views of free trade. 2. Netta and Jim had different views on free trade. 3. Netta and Jim were sharply split over the issue of free trade. 4. Netta and Jim refused

90. Math

Find the speed of a point on the rim of a 24cm diameter fly wheel which is turning at 2800 revolutions per minute. Give your answer in meters per second.

91. Physics 1

An astronaut in her space suit has a total mass of m1 = 76.9 kg, including suit and oxygen tank. Her tether line loses its attachment to her spacecraft while she's on a spacewalk. Initially at rest with respect to her spacecraft, she throws her oxygen tank

92. Physics

A solid metal ball and a hollow plastic ball of the same external radius are released from rest in a large vacuum chamber. When each has fallen 1 m, they both have the same 1. momentum. 2. inertia. 3. speed. 4. change in potential energy. 5. kinetic

93. physics @ elena

can you please help me with this one At serve, a tennis player aims to hit the ball horizontally. part a)What minimum speed is required for the ball to clear the 0.90m--high net about 15.0m from the server if the ball is "launched" from a height of 2.50m ?

94. Trig

A carousel with a 50-foot diameter makes 4 revolutions per minute. a) Find the angular speed of the carousel in radians per minute. b) Find the linear speed in feet per minute of the platform rim of the carousel.

95. Chem

A radiation lab orders 64uCi of P-32. After 42 days the activity of the sample is 8.0uCi. What is the life of P-32? Thanks

96. Math (geometry)

Find the area of the region inside the circle x^2+y^2=2 AND above the line y=1.

97. math

an isosceles triangle has perimeter of 15m. Find all integral possibilities for the lengths of the side in meters. Hint: the sum of the lengths of any two sides of a triangle must exceed the third side.

98. AP Environmental Science-Ecosystems

1. What are the physical products of cellular respiration? a. Oxygen and carbon dioxide b. Nitrogen and carbon c. Glucose and oxygen d. Glucose and water e. Water and carbon dioxide 2. If the biomass of flowers that support the butterflies was known to