# andrea

Popular questions and responses by andrea
1. ## chemistry

treatment of a 0.400g sample of impure potassium chloride with an excess of AgNO3 resulted in the formation of 0.733g of AgCl. calculate the percentage of KCl in the sample. show balanced equations in support of your answer

2. ## Physics

the speed of the train is reduce uniformly from 15m/s to 7m/s while travelling a distance of 90m. a) compute the acceleration b) how much further will the train travel before coming to rest provided the acceleration remain constant.

3. ## Physics

Europa, a moon of Jupiter has an orbital diameter of 1.34x10^9m and a period of 3.55 days. What is the mass of Jupiter? d=1.34x10^9m T=3.55days = 30672s M=? r=71492000m rm=6.7x10^8 r-total=7414492000m r^3/t^2=GM/4pi^2

4. ## physics multiple choice

A worker pushes horizontally on a 2000 N refrigerator on a kitchen floor with a force of 28.0 N. A. If the refrigerator moves forward, this person feels it pushing back with less than 28.0 N. B. The person always feels a 28.0 N push from the refrigerator.

5. ## math

Let f(x)=4 sqrt(x). If g(x) is the graph of f(x) shifted down 2 units and right 1 unit, write a formula for g(x) like this g(x)= Please help ASAP I don't understand this at all!!! :(

6. ## Math

the stopping distance of an automobile is directly proportional to the square of its speed v. a car required 90 feet to stop when its speed was 70 miles per hour. find a mathematical model that gives the stopping distance d in terms of its speed v. D=

7. ## physics

Which of the following statements about work is or are true? (More than one statement may be true.) A. Negative net work done on an object always reduces the object's kinetic energy. B. If the work done on an object by a force is zero, then either the

8. ## math

An isosceles right triangle has legs of equal length. If the hypotenuse is 22 inches long, find the length of each leg. Please help me on this problem so bad!!! I NEED AN ANSWER TO THIS PROBLEM IMMEDIATELY!!!! :(

9. ## Math

Rewrite in rectangular form: r=6 cos theta I got (x-3)^2+y^2=6

10. ## AP Chemistry

Which of the following bonds is the most polar? A. C-F B. C-C C. C-O D. C-N I was originally going to pick C-F because F is the most electronegative, but I'm not so sure. Help?

11. ## physics

The two angled ropes used to support the crate in the figure below an withstand a maximum tension of 1300 N before they break. The left angle is 30dregres, and the right angle is 45degrees. What is the largest mass the ropes can support? m=?

12. ## Physics

For an electron moving in a direction of the electric field its potential energy _______ and its electric potential _________. Wouldn't the blanks be "increases" and "decreases"? because PE=mgh while V=kq/r

13. ## Math

Question: Add the vectors using components. 3 N in a direction 15° south of west and 4 N in a direction 12° east of south. I have attempted the question and got a resultant of (3.136, -2.06) from (3cos255°, 3sin255°)+(-4cos168°,4sin168°). I do not

14. ## Maths

The angle of elevation of the top of a tower from a point 42m away from its base on level ground is 36°. Find the height of the tower

15. ## Maths

The internal diameter of a spherical bowl half full is 20cm. The contents is poured into an empty cylindrical bottle with internal diameter 10cm. Calculate correct to one decimal places the depth of water in the bottle

16. ## english composition

what is the thesis statement in Why we crave horror movies?

17. ## Chemistry

Calculate the volume of Ba(OH)2 0.20 M necessary to neutralize 300.0 mL of H3PO4 0.30 M. (4 marks)

18. ## math

Two pipes can be used to fill a pool. Working together, the two pipes can fill the pool in 2 hours. The larger pipe can fill the pool in 3 hours less time than the smaller pipe can alone. Find the time to the nearest tenth of an hour it takes for the

19. ## Gen Chem

ignition of mgnh4po4*6h2o produces nh3, h2o and magnesium pyrophosphate, Mg2P2O7. complete and balance the equation for this reaction. If 5.00 g of MgNH4PO4*6H2O are ignited, how many grams of Mg2P2O7 would be formed? 2MgNH4PO4*6H2O(g)--->

20. ## Chemistry

Which of the following pairs of compounds will give a precipitate in a diluted solution?** a) Cu(NO3)2 and Na2CO3 b) KNO3 and NaCl c) MgCl2 and Ba(NO3)2 d) NH4Cl and Al2(SO4)3 A solution contains I-, Br- and OH- ions. If Ag+ is added, what will the

21. ## trig

The terminal side of θ lies on a given line in the specified quadrant. Find the values of the six trigonometric functions of θ by finding a point on the line. Line: (55/48)x Quadrant:III sin(θ)= cos(θ)= tan(θ)= csc(θ)= sec(θ)= cot(θ)=

22. ## Physics

Compared to yesterday you did 3 times the work in one third the time. To so so your power output must have been: a) the same as yesterday's power output b)one third of yesterday's power output c)3 times yesterday's power output d)9 times yesterday's power

23. ## math

A recipe requires 3 1/2 cups of milk. Sam put in 1 3/4 cups and emptied the container. How much more milk does she need to put in? Please help ASAP!!! :(

24. ## AP Chem

Which molecule has the strongest intermolecular forces? A. HOCH2CH2CH2OH B. CH3CH2CH2OH C. CH3CH2CH2CH3 D. HOCH2CHOHCHOHCH2OH I'm pretty sure it's C.

25. ## chemistry

when 45g of an alloy is dropped into 100.0 g of water at 25c, the final temperature is 37c. what is the specific heat of the alloy

26. ## Chemistry

A weak acid solution, HX 0.37 M, has a pH of 3.70. Calculate the acidity constant for this acid.

27. ## Physics

a bomb is dropped from an airplane travelling horizontally with a speed of 300 mi/hr if the airplane is 10000ft. above the ground, how far from the target must it be released, neglect friction?

28. ## physics

Two balls having different masses reach the same height when shot into the air from the ground. If there is no air drag, which of the following statements must be true? (More than one statement may be true.) A. Both balls left the ground with the same

29. ## math

A baseball team plays in a stadium that holds 66000 spectators. With the ticket price at \$12 the average attendence has been 29000. When the price dropped to \$9, the average attendence rose to 33000. Assume that attendence is linearly related to ticket

31. ## statistics

The assets(in billions of dollars) of the four wealthiest people in a particular country are 43,25,21,15 assume that samples of size n=2 are randomly selected

32. ## physics

A 40%-efficient car engine accelerates the 1300 kg car from rest to 20 m/s How much energy is transferred to the engine by burning gasoline? .

33. ## Chemistry

1. A spaceship is found to have a tiny leak that allows the effusion of air into space. Air in the spaceship is a mixture of nitrogen (N2), oxygen (O2), argon (Ar), and trace amounts of other gases. a. Predict which of the three main gases will have the

34. ## math

Graph a circle that has its center at (0,0) and passes through (2,2). Please help ASAP!!! :( I don't know how to do this!!!

35. ## Physics

a ball is released from rest and rolls down in an inclined plane, requiring 4 sec. to cover a certain distance of 100m. a) what is the acceleration? b) how many cm would it have fallen vertically in the same time?

36. ## earth

HELP? Two students are given cubic boxes, measuring 10 cm on a side. Robert puts a single glass marble with a diameter of 10 cm in the box. Susan puts 1,000 1-cm glass marbles in her box. 1.Whose box has more empty space? Explain. 2.Whose box will be

37. ## Physic

What is the period of revolution of a satellite with mass m that orbits the earth in a circular path of radius 7820 km (about 1450 km above the surface of the earth)?

38. ## Physics

A medical technician is trying to determine what percentage of a patient's artery is blocked by plaque. To do this, she measures the blood pressure just before the region of blockage and finds that it is 1.20×10^4 Pa, while in the region of blockage it is

39. ## algebra 1 I NEED HELP!!

the bottom of a 25-foot ladder is placed 7 feet from a wall. How far will the ladder reach up? Since the ladder, wall, and ground form a right triangle, you can use this formula: A squared + B squared = C squared A = 7 feet C = 25 feet B = distance the

40. ## chemistry

Copper used in electric wires comes in two flavors (isotopes): 63Cu and 65Cu. 63Cu has an atomic mass of 62.9298 amu and an abundance of 69.09%. The other isotope, 65Cu, has an abundance of 30.91%. The average atomic mass between these two isotopes is

41. ## physics multiple choice

A force F is required to push a crate along a rough horizontal floor at a constant speed V with friction present. What force is needed to push this crate along the same floor at a constant speed 3V if friction is the same as before? A. A constant force 3F

42. ## Math

According to a rating agency, a car's MPG (miles per gallon) ratings are: 25 MPG for city and 30 MPG for highway driving. A driver spent \$20.00 (the gasoline costs \$1.25/gallon) on a combined city and highway trip of 450 miles. How many miles "C" in city

43. ## Physics

A lever is 5m long. The distance from fulcrum to the weight to be lifted is 1m. If the worker pushes on the opposite end with 400N, what is the max weight that can be lifted? l=5m h=1m F=400N F_g=? torque=F_g*l I first must find torque so that I can plug

44. ## Pre-Calculus

Find a polynomial of degree 4 that has a integer coefficients and zeros 1,-1,2 and 1/2 (one half)?

45. ## Physics

Europa, a satellite of Jupiter, appears to have an ocean beneath its icy surface. Proposals have been made to send a robotic submarine to Europa to see if there might be life there. There is no atmosphere on Europa, and we shall assume that the surface ice

46. ## Science

Why is ∆T metal < 0? and Why is ∆T water > 0? Please help ASAP I don't understand these questions at all!!! :(

48. ## Math

On his last four tests, Danib scored 55%, 78%, 84% and 93%. What score should he get on his next text so that his average on all five tests are 80%?

49. ## English

After which type of assessment will you be asked to set goals for yourself?

50. ## Physics

A playground merry-go-round of radius R = 1.92m has a moment of inertia of I = 221kgm^2 and is rotating at 14.0rev/min about a frictionless vertical axle. Facing the axle, a 29.8kg child hops onto the merry-go-round and manages to sit down on its edge.

51. ## Biology

Plant -+ Deer --+ Tiger The first step in the energy chain that created the bonds of proteins in the tiger's muscle cells in the food chain shown above is the A. deer the tiger ate. B. plant the deer ate. C. photons the sun made. D. carbohydrates the plant

53. ## math

The volume of a sphere of radius r is V=4/3πr^3.Solve for r.

Mr.Baker has baked some muffins. If he packs them in boxes of 4, he will have 3 left over. If he packs them in boxes of 5, he will also have 3 left over If he packs them in boxes of 6, he will have only 1 left over. Find the least possible number of

55. ## Chemistry

Acetic acid dissociates/ionizes itself as follows: CH3COOH(aq) ⇔ H+(aq) + CH3COO-(aq) If you add sodium acetate, CH3COONa, to the solution: a) a precipitate will be formed b) more acetic acid will be ionized c) the concentration of hydrogen ions will

56. ## Math

Suppose you have two alcohol+water solutions. One solution ( of volume x liter ) is 45% alcohol, while the second solution (of volume y liter) is 75% alcohol. What values of "x" and "y" (in liters) will fill a total volume of 5.0 liter which contains 2.88

57. ## Physics

Complete the following statement: The term net force most accurately describes: a) quantity that causes displacement b) quantity that keeps the object moving c) the mass of the object d) the quantity that changes the velocity of an object c) is not the

58. ## Math

Suppose A is directly proportional to the square of B,and A=45 when B=3. a)Find the constant of proportionality b)Write the formula for A in terms of B c)Use your formula to find A when B=6

59. ## Amerian government

PLEASE PLEASE PLEASE HELP ME 1. What type of power does the Constitution grant to the Supreme Court? (1 point) executive power federal power judicial power legislative power 2. Which are examples of judicial restraint in the Supreme Court? Select all that

60. ## chemistry

Which one of the following statements regarding ideal gas laws is FALSE? Select one: a. An ideal gas has an infinite heat capacity b. The macroscopic ideal gas equation is PV = nRT c. The temperature must always be measured in Kelvin (K) d. A single

61. ## chemistry

what mass of ammonium chloride is dissolved in 100 grams water in each of the following solutions in 1.10 molal NH4Cl solution, in a solution which is 75% water by mass in solution with a mole fraction of 0.15 NH4Cl? please help me solve this problem.

62. ## Precal

Consider the line segment joining A(-1,2) and B(3,4) a) find an equation that expresses the fact that a point P(x,y) is equidistant from A and from B. b) describe geometrically the set of points described by the equation in part (a).

63. ## physics

Consider two frictionless inclined planes with the same vertical height. Plane 1 makes an angle of 25.0 degree with the horizontal, and plane 2 makes an angle of 55.0 degree with the horizontal. Mass m_1 is placed at the top of plane 1, and mass m_2 is

64. ## Help with maths!

A rectangular field is surrounded by a fence on three of its sides, and a straight hedge on the fourth side. If the length of the fence is 320m, find the maximum area of the field enclosed. So...how should i do it? Does it matter which of the 'three sides'

65. ## College Statistics 2

I saw that this was already answered but I can't find it if anyone knows, can you point me in the right direction? A recent poll of 700 people who work indoors found that 278 of them smoke.If the researchers want to be 98% confident of thier results to

66. ## Pre-Calculus

A car manufacturing company (the Company) can produce a car for \$3000.00 and a truck for \$5000.00. Suppose "C" cars and "T" trucks are sold to the dealer at mark-ups, respectively, of 20 and 30 percent. If the Company made a profit of \$27 million on sales

67. ## Math

Find the value of tan(1/2sin^-1 15/17) and sin[pi/2-cos(1/2)] Thanks.

68. ## Algebra

: if the quotient 3m^2 +15m / m^2 divided by 30/ m^2 + 5m is simplified to lowest terms, which of the following is the denominator of the resulting expression? the options are 10 30m^2 m^2 +5m or m^2( m+5) 10, with the restriction that m cannot be zero.

71. ## Chem

What is the pKb of Formate ion? 0.64M ........... 8.77 pH Help!! I'm not sure how to calculate this... I know to use the Kb formula but I'm not sure where to plug the numbers in.

72. ## math

The formula for the surface area of a cylinder is A=2πr^2+2πrh. (A)Solve for r and simplify the result, if possible. (B) If the surface area of a cylinder is 100 square feet and the height is 40 inches, what is the radius of the cylinder in units of

73. ## math

The cookie dough used by a bakery to make 2-ounce cookies contains an average of 32 raisins per pound of dough. the bakery sells cookies in bags of a dozen. suppose that customers complain if one or more of the cookies in a bag contains no raisins. over

74. ## AP Chem

Which of the following conditions would most likely affect the rate of a chemical reaction? A. Increasing the number of reaction steps B. Decreasing the size of the reaction vessel C. Increasing the concentration of reactants D. Decreasing the amount of

75. ## Linguistics

What are three different ways an English speaker might make the borrowed Polish place name Szczebrzeszynie[ʃtʃɛbʒɛʃɨɲɛ]fit within English phonotactics?

76. ## Physics

Two 2.46uC point charges are located on the x axis. One is at x = 1.01m, and the other is at x = -1.01m. Determine the electric field on the y axis at y = 0.455m & Calculate the electric force on a -2.82uC charge placed on the y axis at y = 0.455m I'm

77. ## IPC

A motorcyclist changes the velocity of his bike from 20.0 meters/second to 35.0 meters/second under a constant acceleration of 4.00 meters/second2. How long does it take the bike to reach the final velocity?

78. ## Chemistry

Given the following reaction: HCl(g) + SrO(s) ¨ SrCl2(s) + H2O Calculate the mass of HCl in grams that would react with 11.44 kg SrO.

79. ## chemistry

a compound containing 3 atoms of carbon and 8 atoms ofhydrgen is combined in a reaction with oxegyn molecules the two end products of this equation are carbon dioxide co 2 and water what elemement should i look at first in balancing this equation oxygen

80. ## chemistry

a carbon containing 3 atoms of carbon and 8 atoms of hydrdren combinend in reactionwith oxygen molecules the 2 end products of this equation are carbon dioxide co 2 an water what element should i look at first inn this oxygen hydrogen carbon or dioxide and

81. ## mathematics

quotient of one and a number xxx.

82. ## math

How much time would it take for 5.2 x 105 atoms of fermium-253 (half-life 3 days) to decay to 6.5 x 104 atoms?

83. ## math

A balloon is secured to rope that is staked to the ground. A breeze blows the balloon so that the rope is taut while the balloon is directly above a flag pole that is 60 feet from where the rope is staked down. Find the altitude of the balloon if the rope

84. ## history

In “The Raven and the First Men: The Beginnings of the Haida,” which evidence best helps the reader infer that the Haida might find it acceptable behavior to play tricks on one another?

85. ## AP Chemistry

When does absorption occur in infrared spectroscopy? A. When the frequency of the infrared radiation is the same as the rotational frequency of the bond B. When the frequency of the infrared radiation is less than the frequency of the bond C. When the

86. ## Math

Is the value of the second 5 in 450,852,137 one-tenth the value of the first 5 ? Explain

87. ## Statistics

Assume that a procedure yields a binomial distribution with a trial repeated n times. Use the binomial probability formula to find the probability of x successes given the probability p of success on a single trial. n=19, x=15 p=.85, find P(15)

88. ## calculus

An angler has a fish at the end of his line, which is being reeled in at the rate of 2 feet per second from a bridge 30 feet above the water. At what speed is the fish moving through the water towards the bridge when the amount of line out is 50 feet?

89. ## chemistry

isotope chromium -51 has a half life of 28 days. If the original sample had a mass of 28.0 grams, what mass of chromium -51 sample remains after 84 days?

90. ## statistics, math, college

if np >5 and nq>5 estimate P (fewer than 4) with n=13 p=0.4 by using normal distribution as an approximate to the binomial distribution if np

91. ## Physics

A block of mass m1=1.6kg, initially moving to the right with a velocity of +4m/s on a frictionless horizontal track, colides with a massless spring attached to a second block of m2=2.1kg moving left with a velocity of -2.5m/s. The spring constant is 600

92. ## Chemistry

Balance the equation and write the reaction-quotient expression, Qc. U(s) + F2 (g) UF6 (g)

93. ## Chemistry

Consider the reaction 3X + Y ⇔ 2W + Z. At equilibrium, [X] is 7.0 M, [Y] is 6.0 M, [W] is 5.0 M and [Z] is 7.0 M at 298 K. The value of the equilibrium constant at this temperature is: a) 0.085 b) 0.560 c) 1.800 d) 11.760

94. ## Chemistry

Are the reactants or the products favoured in the following reactions? a. CH3COOH with NH3? b. HS- with HCO3-? c. HNO2 with NH3 d. NH4+ with F- e. C6H5COOH with CH3COO- f. H2SO3 with HCO3- g. H2CO3 with SO32- h. H2SO3 with SO32-

95. ## math

Vail Ski Shop received a \$1,201 invoice dated July 8th wiht 2/10, 1/15, n/60 terms. On July 22, Vail sent a \$485 partial payment. What credit should Vail receive? What is Vail's outstanding balance?

96. ## physics

A block slides a distance d down a frictionless plane and then comes to a stop after sliding a distance s across a rough horizontal plane. What fraction of the distance s does the block slide before its speed is reduced to one-third of the maximum speed it

97. ## physics multiple choice

A person pushes horizontally with constant force P on a 230 N box resting on a frictionless horizontal floor. Which of the following statements about this box is correct? A.The box will accelerate no matter how small P is. B. The box will not accelerate

98. ## physics

A Ferris wheel with radius 14.0 m is turning about a horizontal axis through its center, as shown in the figure below. The linear speed of a passenger on the rim is constant and equal to 6.00 m/s. A.What is the magnitude of the passenger's acceleration as