# Alex

Popular questions and responses by Alex
1. ## Chemistry Help

Write the net ionic equation for the reaction of calcium nitrate and sodium phosphate

2. ## Physics

A girl of mass 55 kg throws a ball of mass 0.8 kg against a wall. The ball strikes the wall horizontally with a speed of 25 m/s, and it bounces back with the same speed. The ball is in contact with the wall 0.05 s. What is the average force exerted on the

3. ## Chem

2HNO3(aq) + Sr(OH)2(aq) --> 2H2O(l) + Sr(NO3)2(aq)? Write the net ionic equation, including the phases. 2H^+(aq) + 2OH(aq) ---> 2H2O(l) Am I correct?

4. ## Chemistry

I have a question about this one 2N2O(g) ⇋ O2(g) + 2N2(g), what happens to the equilibrium position if the pressure decreases? Is going to shift to the right or to the left???

5. ## US Government

Why do we have more safeguards for accused criminals than the victims themselves?

6. ## calculus

The differential equation below models the temperature of a 87°C cup of coffee in a 17°C room, where it is known that the coffee cools at a rate of 1°C per minute when its temperature is 67°C. Solve the differential equation to find an expression for

7. ## physics

Driving in your car with a constant speed of v= 22 m/s, you encounter a bump in the road that has a circular cross-section, as indicated in the figure (Figure 1) . Part A If the radius of curvature of the bump is 52 m, find the apparent weight of a 66-kg

8. ## Physics

A pile driver lifts a 450 kg weight and then lets it fall onto the end of a steel pipe that needs to be driven into the ground. A fall of 1.5 m drives the pipe in 45 cm. What is the average force exerted on the pipe?

9. ## Physics

A spring is stretch 40mm by a force of 15N ...what's the work done

10. ## math

Four corners are cut from a rectangular piece of cardboard that measures 5 ft by 3 ft. The cuts are x feet from the corners, as shown in the figure below. After the cuts are made, the sides of the rectangle are folded to form an open box. The area of the

11. ## Statistics

Which of the following is NOT sensitive to extreme values? A) the range B) the standard deviation C) the interquartile range D) the coefficient of variation I pick B the standard deviation

12. ## US Government

people who believe voting is important have high political ...? what clue:(8-letter word) ----c-c-.

13. ## Chemistry - Please check

d) 2Al(s) + Fe2O3(s)  2Fe(l) + Al2O3(s) Oxidation 2Al(s)  2Al+ + 2e- Reduction Fe23+ + 3e-  2Fe(l) Oxidation numbers for chlorine HCl = -1 MnO2(s)= +4 KMnO4(s)= +7 Oxidation numbers for manganese Mn(s)= ? MnCl2(s)= +7 Mn2+(aq)= ? MnO4- =? And then

14. ## Chemistry

Round each number to two significant figures: 233.356 0.002353 1.005 Can you please show me and explain how to do this? Im confused. thank you!!!

15. ## statistic

A survey found that​ women's heights are normally distributed with mean 62.5 in. and standard deviation 2.7 in. The survey also found that​ men's heights are normally distributed with a mean 67.9 in. and standard deviation 2.8 . Complete parts a

16. ## Physics

A 50 Kg box rests on a horizontal surface. The coefficient of Static friction between the box and surface is 0.30. The coeffient of Kinetic friction is 0.20. What is the frictional force on the box if a 140 N horizontal push is applied to it. If a 175 N

17. ## algebra

Sal's Sandwich Shop sells wraps and sandwiches as part of its lunch specials. The profit on every sandwich is \$2 and the profit on every wrap is \$3. Sal made a profit of \$1,470 from lunch specials last month. The equation 2x + 3y = 1,470 represents Sal's

18. ## Algebra 2

A baseball player swings and hits a pop fly straight up in the air to the catcher. The height of the baseball in meters t seconds after it is hit is given by a quadratic function h(t) = −5t^2 + 10t + 1. What is the maximum height of the baseball?

19. ## math

two boxes have the same volume. One box has a base that is 2 inches by 2 inces. The other box has a base that is 4 inches by 4 inches. How many tines as tall is the box with the smaller base

20. ## French

3 - Au marché The new employee can't get anyone's order right. Say what each customer asked for and what the employee gave them. Modèle-je / des frites J'ai demandé des frites, mais il m'a donné du pain. 1. Malika / une pêche Malika demande une peche,

21. ## english

Choose the correct sentence pattern for the sentence below. There is good reason to be thankful. E-V-S S-V-DO-OC S-LV-PA S-V-DO S-V-IO-DO S-V S-LV-PN Question pattern

22. ## Physics

A quantity of monatomic ideal gas expands adiabatically from a volume of 2.0 liters to 6.0 liters. If the initial pressure is P0, what is the final pressure?

Glenda bought z containers of laundry detergent at \$9 each. She gave the cashier \$50. a. Find the change Glenda received in terms of z. b. If z = 3, how much change did Glenda receive?

24. ## Algebra

A toy rocket that is shot in the air with an upward velocity of 48 feet per second can be modeled by the function f(t)=-16t^2+48t , where t is the time in seconds since the rocket was shot and f(t) is the rocket’s height. What is the maximum height the

25. ## Chemistry

For C2H5NH3+, write an equation that shows how the cation acts as an acid. Why is my answer wrong? CH2H5NH3^+(aq) + H2O(l) ---> CH2H5NH2(aq) + H3O+(aq)

26. ## Trigonometry

Determine the general solution of Sin2x=4cos2x thanks in advance

27. ## order of operations

Find the value of the expression below for r=4 and t=2 t^3-r+20 divided by r 9 72 6* I chose this one 40

28. ## Chemistry

Calculate the pH and the pOH of an aqueous solution that is 0.025 M in HCl(aq) and 0.075 M in HBr(aq) at 25°C.

29. ## Chemistry

A 100.0 mL sample of 0.20M HF is titrated with 0.10M KOH. Determine the pH of the solution after the addition of 100.0 mL of KOH. The Ka of HF is 3.5 x 10^-4

30. ## Physics

A plate falls vertically to the floor and breaks up into three pieces, which slide along the floor. Immediately after the impact, a 200g piece moves along the x-axis with a speed of 2.00m/s and a 235g piece moves along the the y axis with a speed of

31. ## English

I don't quite understand the meaning of the story "Score/Score" by Phyllis Gotlieb. I can't seem to find much about it on the internet.

32. ## Microeconomics

Larry, Moe, and Jo run the only saloon in town. Larry wants to sell as many drinks as possible without losing money. Jo wants the saloon to bring in as much revenue as possible. Moe wamts to make the largest possible profits. Using a single diagram of the

33. ## UCF

What will be the change in enthalpy when 100.0 g of butane, C4H10, is burned in oxygen as shown in the thermochemical equation below? 2 C4H10(l) + 13 O2(g) → 8 CO2(g) + 10 H2O(g) ΔH = −5271 kJ −2636 kJ −4534 kJ −9087 kJ −1.817 × 104 kJ

34. ## math

The UV index on a sunny day can be modeled by the function f(x)=-0.15(x-13)^2+7.6 where x represents the time of day on a 24-h clock and f(x) represents the UV index. At what time(s) was the UV index 7? (2 marks)

35. ## Chemistry

Strong base is dissolved in 675 ml of 0.200 m weak acid (ka=3.25x10^-5) to make a buffer with a ph of 3.95. Assume that the volume remains constant when the base is added. HA + OH ---> H2O + A^- calculate the pka value of the acid and determine the number

36. ## Physics

Water flows into one end of a horizontal, cylindrical pipe at 2.0 m/s. The pipe then narrows until its diameter at the opposite end is only 1/3 of that at the beginning. (a) What is the flow speed at the narrow end of the pipe? (b) What is the pressure

37. ## Math

Courtney and Kurtis are planning to travel 160 km in a car by travelling at x kilometres per hour for the first half of the distance, and then increasing their speed by 10 km/h to finish the distance. Which is the correct simplified expression for the

38. ## algebra

Tasha invests \$5,000 annually at 6% and \$5,000 annually at 8%. Thomas invests \$10,000 annually at 7%. Which statement accurately compares the two investments if interest is compounded annually?

Let line l_1 be the graph of 5x + 8y = -9. Line l_2 is perpendicular to line l_1 and passes through the point (10,10). If line l_2 is the graph of the equation y=mx +b, then find m+b.

40. ## physics

A test rocket is fired straight up from rest. The net acceleration is 20 m/s2 upward and continues for 4.0 seconds, at which time the rocket engines cease firing. What maximum elevation does the rocket reach?

41. ## Algebra

Find k, given that (2,k) is equidistant from (3,7) and (9,1). The answer is : k=0 How do I solve this problem?

42. ## calculus

Find the area of the shaded region. r^2=sin(2θ).

43. ## chemistry

Mixtures of helium and oxygen are used in scuba diving tanks to help prevent ‘the bends’, a condition caused by nitrogen bubbles forming in the bloodstream. If 95 L of oxygen and 25 L of helium at STP are pumped into a scuba tank with a volume of 8.0

44. ## math

jose said all of the multiples of 8 are also multiples of 2. jamila said that all of the multiples of 8 are also multiples of 4. who is correct. Explain

45. ## Algebra

kind of function best models the data on the table used to differences or ratios 0 0.6 1 4.2 2 29.4 3 205.8 4 1440.6

46. ## Math

In a large section of a statistics class, the points for the final exam are normally distributed, with a mean of 72 and a standard deviation of 9. Grades are to be assigned according to the following rule: The top 10% receive A's. The next 20% receive B's.

47. ## math

Arley’s Bakery makes fat-free cookies that cost \$1.60 each. Arley expects 40% of the cookies to fall apart and be discarded. Arley wants a 35% markup on cost and produces 200 cookies. Assume that Arley can sell the broken cookies for \$1.50 each. What

48. ## Physics

A rock is thrown directly upward from the edge of a flat roof of a building that is 56.3 meters tall. The rock misses the building on its way down, and is observed to strike the ground 4.00 seconds after being thrown. Take the acceleration due to gravity

49. ## physics

A 0.395-kg blue bead slides on a frictionless, curved wire, starting from rest at point in the figure below, where h = 1.50 m. At point , the blue bead collides elastically with a 0.650-kg green bead at rest. Find the maximum height the green bead rises as

50. ## physics

A point charge of 2.4 μC is located at the center of a spherical shell of radius 17 cm, which has a charge −2.4 μC uniformly distributed on its surface. Given: ke = 8.98755 × 109 Nm2/C2 . a)Find the electric field for all points outside the spherical

51. ## math

Sixty-five randomly selected car salespersons were asked the number of cars they generally sell in one week. Fourteen people answered that they generally sell five cars; nineteen generally sell six cars; twelve generally sell seven cars; nine generally

52. ## calculus

Find a Cartesian equation for the curve and identify it. (r^2)cos(2θ)=1

53. ## Language Arts

1. Which sentence contains an opinion? (1 point) Thomas Jefferson supported American independence from Great Britain. He was a lawyer in his home state of Virginia. Jefferson authored the Declaration of Independence, the most important document in

54. ## ENG1010

Which of the following is an announcement rather than a topic sentence? A) I want to talk about the increase in the divorce rate. B) Many people have trouble getting along with others. C) Almost one out of every two marriages ends in divorce. D) The

55. ## Physics

Neutral metal sphere A, of mass 0.10kg, hangs from an insulating wire 2.0m long. An identical metal sphere B, with charge -q is brought into contact with sphere A. Sphere A goes 12 degrees away from Sphere B. Calculate the initial charge on Sphere B. Note:

56. ## microeconomics

Mickey is very picky and insists that his mom makes his breakfast with equal parts of cereal and apple juice. Any other combination ends up on the floor. Cereal costs 4 cents per tablespoon and apple juice costs 6 cents per tablespoon. If his mom budgets

57. ## physics

A skateboarder at a skate park rides along the path shown in (Figure 1) . a=2.7 m and b=1.0m If the speed of the skateboarder at point A is v=1.6m/s, what is her speed at point B? Assume that friction is negligible.

58. ## French

Did I do this correctly: 1. Malika / une pêche Malika a demande une peche, mais il lui a donne une poire. 2. Soraya / une tomate Soraya a demande une tomate, mais il lui a donne un oignon. 3. Daniel / du pâté Daniel a demande du pate, mais il lui a

59. ## math

Four corners are cut from a rectangular piece of cardboard that measures 5 ft by 3 ft. The cuts are x feet from the corners, as shown in the figure below. After the cuts are made, the sides of the rectangle are folded to form an open box. The area of the

60. ## math

The line y=16x intersects the quadratic function y=x^2 at two points. What are the coordinates of the two points of intersection?

61. ## Math

A ball is thrown straight up from a bridge over a river and falls into the water. The height, h, in meters, of the ball above the water t seconds after being thrown is approximately modeled by the relation h=-5t^2+10t+35. Can you please help me ! Show your

62. ## Math

The value of k that makes the expression x^2 + 72x +k a perfect square trinomial is ?

63. ## English

What is the meaning of the quote @Life is eternal; and love is immortal; and death is only a horizon; and a horizon is nothing save the limit of our sight." Especially the part- "and a horizon is nothing save the limit of our sight." Thank you

64. ## calculus

Find the area enclosed by the curve x = (t^2)-2t, y = (t)^(1/2) and the y-axis.

65. ## Chemistry

CO(g) effuses at a rate that is ______ times that of Xe(g) under the same conditions.

66. ## Vocab

I’m excited about my vacation. The beach has been calling my name. A. Personification B. Irony C. Hyperbole D. Onomatopoeia A??

67. ## Chemistry

if 5.00 ml of 1.66x10^-1 M HCl solution is diluted to exactly 250.0 ml with water, what is the concentration of the resulting solution?

68. ## Math

Which of the following triangles cannot be solved using the sine law? a) angle a= 28 degrees, angle b= 75 degrees, side a= 24 cm b) side a=4 cm , side b= 11 cm c) angle a=28 degrees, angle c= 34 degrees , side b=5 cm d) angle b= 29 degrees, side b=5 cm,

69. ## Equation help 2 questions

How many real number solutions does the equation have y=-4x^2+7x-8 none one two infinite How many real number solutions does the equation have y=3x^2+18x+27 none one two infinite Thank you!

70. ## math

Matthew parks his car between Karen’s and Patrick’s apartment buildings. The car is 46 m in front of Karen’s apartment building. The angle of elevation from the car to the top of the building is 40°. Matthew’s car is 39 m away from Patrick’s

71. ## Algebra 2

How much of a 60% orange juice drink must be mixed with 30 gallons of a 10% orange juice drink to obtain a mixture that is 50% orange juice.

72. ## Literature 1010

Transitions function much like road signals. A) True B) False this question does not make sense. when i look in my book ans online, i do not see anything referring to the Transitions function can someone tell me what a transition function relating to

73. ## physics

A 550-g ball traveling at 8.0 m/s undergoes a head-on elastic collision with a 250-g ball traveling toward it also at 8.0 m/s. What is the speed of the 250-g mass after the collision?

74. ## spanish

does "fin" have an accent?

75. ## History

Which of these was President Lincoln's central goal during the Civil War? A.To end slavery in all U.S. states B.To preserve the Union****** C.To keep the U.S. economy from collapsing D.To punish the Southern states for seceding Is it B

76. ## algebra

You also have two options for lodging. Write an equation FOR EACH OPTION that depicts the total cost of your stay, y, based on the number of days, x. Bilton Hotel: \$100/night but you must pay an additional one-time fee of \$40 for parking and other fees

77. ## Math

The rectangular backboard of a basketball court needs to be assembled. Its area is given as 18,900 cm2 and the width as 1.8 m. What is the backboard’s length in metres? m

78. ## Math

In a triathlon, a contestant swims 5 km, cycles 30 km, and then runs 20 km. In general, a contestant runs at an average speed of x, swimsat an average speed of x/5, and cycles at an average speed of 5x, where x is in kilometres per hour. a) Determine an

79. ## Econ

The process that produces Sonora Bars (a type of candy) is intended to produce bars with a mean weight of 55 gm. The process standard deviation is known to be 0.77 gm. A random sample of 49 candy bars yields a mean weight of 55.82 gm. Find the test

80. ## Physics

A computer is reading data from a rotating CD-ROM. At a point that is 0.0368 m from the center of the disk, the centripetal acceleration is 274 m/s2. What is the centripetal acceleration at a point that is 0.0781 m from the center of the disc?

81. ## Statistics

A person's level of blood glucose and diabetes are closely related. Let x be a random variable measured in milligrams of glucose per deciliter (1/10 of a liter) of blood. Suppose that after a 12-hour fast, the random variable x will have a distribution

82. ## Chemistry

1.The Volume of oxygen required for the complete combustion of 500ML of ethyne at STP..A)2.00ML B)1.25 C)1.71 D)1.00 2.A Chemical Engineer finds that 250ml CuSO4 reacts with excess NaOH to create 2.37g of precipitate.Calculate the Concentration of

83. ## Physics

A 5.0-kg box at the top of a 400cm ramp slides down 200 cm. How much gravitational potential energy was lost as the box slides from the top of the ramp to the 200 cm mark of the ramp? A cheerleader is thrown vertically upward into the air. As the

84. ## chemistry

if 465 cm3 of sulphur iv oxide can diffuse through porous partition in 30seconds how long will an equal volume, 620cm3 of hydrogen sulphide take to diffuse through the same partition (h=1,s=32,o=16

85. ## Chemistry

A particular natural gas consists, in mole percents, of 83.0% CH4, 11.2% C2H6, and 5.8% C3H8. A 385L sample of this gas is measured at 25C and 729mmHg, and is burned in an excess of oxygen. How much heat in kJ is involved in this reaction. I assume you use

86. ## History

All day long and in all places I am always fastening upon you, stirring you and persuading you and reproaching you. You will not easily find another like me. Use the passage to answer the question. 1. In the passage, what Greek philosopher describes his

87. ## French, foreign languages

Hi, I desperately need help with double object pronouns in French. Here are questions that I am working on and I can't make heads nor tails of them: L'agence de voyages a envoyé les billets d'avion à mes parents. Mes parents ont acheté de grandes

88. ## Algebra

Evan washes two types of vehicles. It takes him 30 minutes to wash a car and 40 minutes to wash a truck. He charges \$12 to wash a car and \$15 to wash a truck. In 270 minutes, Evan made \$105 washing cars and trucks. How many trucks did Evan wash?

89. ## pre cal

f(x) = two divided by quantity x squared minus two x minus three Graph A coordinate axis scaled by one. Domain and Range : _____________________ x and y Intercept(s) : _____________________ Horizontal Asymptote(s) : ___________________ Vertical

90. ## science

all of the following are explanations for glacial periods EXCEPT. a. varying solar energy b. volcanism c. biological organisms d. Earth's orbit's precession

91. ## chemistry

Hydrogen iodide reacts with itself to give hydrogen and iodine. The equilibrium constant is about 2.0 x 10─3 at a particular temperature. If you were to place some hydrogen iodide in a container and seal the container, what would you expect to find at

92. ## statistics

You are a travel agent and wish to estimate, with 98% confidence, the proportion of vacationers who use an online service or the Internet to make travel reservations. Your estimate must be accurate within 4% of the population proportion. a) No preliminary

93. ## Literature 1010

A topic statement is made up of a limited topic and a writer's point about the limited topic? True Or False.

94. ## pals help

An air-track cart with mass m1=0.29kg and initial speed v0=0.95m/s collides with and sticks to a second cart that is at rest initially. Part A If the mass of the second cart is m2=0.55kg, how much kinetic energy is lost as a result of the collision?

95. ## Math

In a large section of a statistics class, the points for the final exam are normally distributed, with a mean of 72 and a standard deviation of 9. Grades are to be assigned according to the following rule: The top 10% receive A's. The next 20% receive B's.

96. ## Geometry

I need help!!! a hemispherical bowl with radius 25cm contains water whose depth is 10cm. what is the water's surface area

97. ## chemistry

In the following reaction, how many liters of oxygen produce 560 liters of carbon dioxide in the oxidation of methane, given that both gases are at STP? CH4 + 2O2 ¨ CO2 + 2H2O

98. ## Property help

Which property is illustrated by the following statement (3z)xy=3(zx)y Associative property of multiplication Communative property of Multiplication Inverse property of multiplication Communative of Addition My answer is commnative property of addition am