1. Math

The public library has an aquarium in the shape of arectangle prism . The base is 6 feet by 2.5 feet and the height is 4 feet . How many square feet of glass were used to build the aquarium (the top of the aquarium is open).

2. Chemistry URGENT

A student heated a hydrated salt sample with an initial mass of 4.8702 g, After the first heating, the mass had decreased to 3.0662 g (two part question) 1. if the sample was heated to constant weight after reheating, what is the minimum mass that the

3. statistics (7)

The average cost per night of a hotel room in New York City is \$273 (SmartMoney, March 2009). Assume this estimate is based on a sample of 45 hotels and that the sample standard deviation is \$65. a. With 95% confidence, what is the margin of error (to 2

4. chemistry URGENT

I need someone to check my answers to make sure that I have the correct answers. (3 Part Question) Two students each measure the density of a quartz sample three times: Student A Student B 3.20 g/mL 2.82 g/mL 2.58 g/mL 2.48 g/mL 2.10 g/mL 2.59 g/mL mean

5. Physics

A disk at rest experiences a constant angular acceleration for t = 85 s, at the end of which it is spinning with a frequency of f = 45 rpm. Please answer the following questions. A)Write an expression for the magnitude of the angular velocity of the disk

6. Chemistry

Iodine 131 is a radioactive isotope. After 4.00 days, 70.8% of a sample of 131I remains.What is the half life of 131I?

7. Deepa

A bus service carries 10 000 people daily between Ajax and Unoin Station, and the company has space to serve up to 15 000 people per day. The cost to ride the bus is 20\$. Market research shows that if the fare increases by \$0.50, 200 fewer people will ride

8. Trig

Write a quadratic equation whose roots are 5 + i radical 2 and 5 – i radical 2 ____ x^2 + _____ x+ ______=0

9. physics

A stone is dropped from the deck of the bridge. The sound of the splash reaches the deck 3 seconds later. If sound travels at 342 m/s in still air, how high is the deck of bridge above the water?

10. Science

A uniform meter scale is suspended from 40 cm mark when weight of 25 gf and 10 gf are suspended at 5 cm mark and 75cm mark respectively. Calculate the weight of the meter scale.

11. statistics

The state bridge design engineer has devised a plan to repair North Carolina's 4420 bridges that are currently listed as being in either poor or fair condition. The state has a total of 13,168 bridges. Before the governor will include the cost of this plan

12. Chemistry

How many of the following changes would alter the numerical value of the equilibrium constant Kp for the reaction 2OF2(g) ⇀ ↽ O2(g) + 2F2(g)? I) an increase in temperature II) a decrease of the container volume III) adding more O2 at constant volume

13. math

a train travels 68 km at an average speed of 51 km/h. it then travels another 20 km at an average speed of 40 km/h before reaching its destination. calculate the average speed of whole journey?

14. Science

What are 3 limitations for modeling mitosis?

15. physics

The drawing shows a top view of a square box lying on a frictionless floor. Three forces, which are drawn to scale, act on the box. Consider an angular acceleration with respect to an axis through the center of the box (perpendicular to the screen). Which

16. Pre algebra

A cyclist rides her bike at a speed of kilometers per hour. What is this speed in kilometers per minute? How many kilometers will the cyclist travel in minutes? Do not round your answers.

a) Estimate the area under the graph of f(x)=7+4x^2 from x=-1 to x=2 using three rectangles and right endpoints. R3= ??? Then improve your estimate by using six rectangles. R6= ??? Sketch the curve and the approximating rectangles for R3 and R6? b) Repeat

18. Science

1. If the net force on an object is O N, the forces are considered unbalanced true false 2. Most people in the united states use feet and miles to measure distance in their everyday lives. why do scientist in the United States use meters to measure

19. physics

Which one of the following statements describes the condition(s) for which a rigid body is in equilibrium? Only internal forces can be present. The sum of the externally applied forces must be zero, and the sum of the externally applied torques must be

20. math

If a movie starts at 12:10pm and is 2 hours 20 minutes long. What time will the movie end?

21. accounting

The Sneed Corporation issues 10,000 shares of \$50 par value preferred stock for cash at \$75 per share. The entry to record the transaction will consist of a debit to Cash for \$750,000 and a credit or credits to:

22. Trig

If sec A =5/4 and A is an angle in Quadrant IV, find the value of cos A. A. -4/5 B.4/5 C.-5/4 Is it choice A

23. chemistry

the freezing point of water is -1.86 degree Cm, if 5.00 g Na2SO4 is desolve at 45.0g H2o the freezing point is changed by -3.82 degree C. Calculate the Van't Hoff Factor for Na2SO4

24. Chemistry

NH4NO3(s) ¡æ N2O(g) + 2H2O(§¤). How much water is produced if 22.9 g of N2O is produced in this reaction? Answer in units of g I converted grams of N2O to mol. Then I did a mol ratio getting mol of H2O. Then I converted mol of H2O to grams. I got

25. PreCalculus

A lake formed by a newly constructed dam is stocked with 1,000 fish. Their population is expected to increase according to the logistic curve N=30/(1+29e^-1.35t) where N is the number of fish, in thousands, expected after t years. The lake will be open to

26. chemistry

how many grams of HCL is needed to produce 200 grams of hydrogen?

27. math (trade and cash discount)

5.mariam paid RM239.29 for a bag that was offered a chain discount of 15% and 8% .what was the list price of the bag ?

28. Chemisrty

the freezing point of water is -1.86 degree Cm, if 5.00 g Na2SO4 is desolve at 45.0g H2o the freezing point is changed by -3.82 degree C. Calculate the Van't Hoff Factor for Na2SO4

29. UOS

A parallel plate capacitor has a capacitance of 7.0mF when filled with a dielectric. The area of each plate is 1.5m2 and the separation between the plates is 1.0x10-5m. What is the dielectric constant of the dielectric?

30. Precalculus

Sets A,B and C are subsets of U. U= positive integers less than 16 A= prime numbers B= factors of 36 C= multiples of 4 (A intersect B)' union C {?} My answer: 1,4,5,6,7,8,9,10,11,12,13,14,15 union 4,8,12 {4,8,12}

31. Math

Gina is adding a lace border to a circular pillow. The raduis of the pillow is approxmately 8 inches,and she needs to decide how much lace to buy. What length should she buy?

32. Physics

A 1900 kg Oldsmobile traveling south on Abbott Road at 13.6 m/s is unable to stop on the ice covered intersection for a red light at Saginaw Street. The car collides with a 3854 kg truck hauling animal feed east on Saginaw at 9.8 m/s. The two vehicles

33. Calculus

Ian's house is located 20km north of Aida's house. At 9am, one saturday, Ian leaves his house and jogs south at 8km/hour. At the same time Aida leaves her house and jogs east at 6km/h. When are Ian and Aida closest together given that they both run for 2.5

34. Ethics in Criminal Justice

Which of the following refers to a form of human motivation whereby our decisions and actions are motivated primarily (if not exclusively) by our own interests? A. Egoism B. Psychological determination C. Altruism D. Ethnocentrism Is it A?

35. QZIA

Write an algorithm that reads the names of 10 students, their weights in kilograms, five test scores for each student and then prints the name of each student, his weight in pounds, and his average test score.

36. Maths

Cam and Dean are playing a game with counters and dice. Cam has some counters, each labelled 1 on one side and 2 on the other. He flips the counters and scores the total of all the numbers showing. Dean has one die and scores the number showing after he

37. finance

If the average new home costs \$ 275,000 today, how much will it cost in 10 years if the price increases by 5 percent each year?

38. math (2)

Find the area of the shaded region y= 2x/(x^2+4) from x= -1 and x= 1 Note: People have been telling me that the two lines do not intersect but they do there has to be an answer. please help me. Thanks

39. math

Company ABC offers a series discount of 20%,10% and 4% on a type of water filter while company XYZ offers a single discount of 32% on the same type of water filter. Which company offers a greater discount on its merchandise assuming the list price is the

40. science

Why are there usually more producer in an ecosystem than consumers? a). There is less energy available to the consumers. b). There is more energy available to the consumers. My answer is ( a ).

41. h school

Which of the following is an abundant natural resource found in Canada?

42. MATH

is the polynomial:: y^2-25x+25 a difference of squares, if so factor it. Thank you so much!!

43. Chemistry 2

calculate the PH of a mixture containing 30 mL, 0.10M HC2H3O2? (Ka=1.8x10^-8 of HC2H3O2)

44. statistics

A researcher believe that college students spend a different amount of time talking on the phone than they do instant messaging. She takes a random sample of 12 college students and records the number of hours per week each student spends on each activity

45. statistics

Some students were asked, "Would you date someone with a great personality even though you did not find that person to be attractive?" Of the 131 women surveyed, 61.1% said yes, and of the 61 men surveyed, 42.6% said yes. Is there sufficient evidence to

46. ap statistics

What would the null and alternate hypothesis be? A fire insurance company felt that the mean distance from a home to the nearest fire department in a suburb of Chicago was at least 4.7 miles. It set its fire insurance rates accordingly. Members of the

47. physics

A diagram shows two cylinders containing two pistonsA and B. The two cylinders are connected with a tube containing a fluid. The system is similar to the hydraulic braking system of a car. A man pushes down on piston A while piston B has a 10kg mass

48. Math

Simplify. 12n^2m^4 ________ 28n^4m^3 thank you!

49. Chemsitry

If Kc = 6.38 × 105 for the reaction A(g) ⇀ ↽ 2B(g), what is Kc for the reaction written as 2B(g) ⇀ ↽ A(g)? How would I solve this?

50. Math

An exponential function with a base of 3 has been vertically stretched by a factor of 1.5 and reflected in the y-axis. Its asymptote is the line y=2. Its y-intercept is (0,3.5). Write an equation of the function and state its domain and range.

51. Mathematics

How would i go about tranposing this equation so that I end up with a value for x? Please include working. Thankyou 315.414=2πx^2+860.16/x

52. math

2.FIND THE TRADE DISCOUNT cost price = RM1780 rate of trade discounot = 30%,10% and 5% as we know to get trade discount is= list price X trade disount rate so i do : RM1780x0.3xo.1xo.o5 = RM2.67 BUT in my book the answer is RM714.67. WHAT the step or

53. physics

explain to me the process doping. what is it? how is it done?

(-3)^5

55. Chemistry URGENT

I need help figuring out the calculations of my experiment. I'm sure I did something wrong cause I can not figure how to calculate the mass of sodium chloride. My measurements follow. 1. 250 mL beaker = 8.4 2. Mass of container = 0.4013 3. mass of

56. ap statistics

What would the null and alternate hypothesis be for this problem? The manager at Air Cargo feels that the weights of packages shipped recently are less than in the past. Records show that in the past packages have had a mean weight of 36.7 lb. and a

57. Chemistry URGENT/DR BOB

Hello DR. BOB, the correct value in the problem posted at 1:17pm regarding Student A and Student B accuracy and random error is the: MEAN of 2.63 g/mL. Could you take a look back at that post and let me know if i answered 2 and 3 correctly.

58. Alegra

Suppose that a spreadsheet contains the following values. A1 6 B1 -4 C1 2 D1 3 Determine the value of cell E1 if it contains the following formulas. a) +A1 + B1 E1= 2 got that one right b) +4*A1 + 5*B1 got that one wrong c) +C1*(A1 +3*B1) got that one

59. Writing Skills

Where would you go to find an article on recent fashion trends? A. Encyclopedia B. Reader's Guide C. Card catalog D. Who's Who

60. Chemistry URGENT

I need help to evaluate if I completed my experiment calculation. determination of water in a hydrate. 1. Mass of crucible, and cover = 18451.3 2. Mass of crucible, cover and sample = 23410.2 3. Mass of crucible, cover and sample after 1st heating =

61. Math

lets start over with this problem: n^2 - 9n + 9 how do you determine if this is a perfect square, and can you factor it?

62. math

What is 9.2-3567+(87+2-6736)

63. introduction to finance

If upon retirement in 20 years Greg plans to invest 800,000 in a fund that earns 4 percent, What is the maximum annual withdrawal he can make over the following 15 years

64. Math (6)

Find the area of the following two curves. y= sqrt(x) y= x-2 Note: People have been telling me that the two lines do not intersect but they do there has to be an answer. please help me. Thanks

65. chemistry

2H2(g) + S2(g) ¡ê 2H2S(g) Analysis of the contents of a 15.0L flask reveals that there are 4.4 moles of hydrogen gas, 2.0 moles of sulfur gas, and 3.7 moles of hydrogen sulfide gas in the flask at equilibrium. Calculate the equilibrium constant K

66. Math

(2 + sqrt 2)/(2 - sqrt 2) = (x)/(3 + sqrt 10) How to solve for x?

67. Physics

Your teenage kid finally gets his drivers license. He takes off in your brand new car that weighs 2000kg at 47m/s when he hits a parked semi that weighs 40000kg. They plow forward in a perfectly in elastic fashion in the same direction. What is the

68. maths

a jar contains 10 red and 30 green.how many marbles shud b added to it so dat 60% marbles r red?

69. maths

1.hw many 3 digit nos are divisible by 7? 2.wat is d sum of product and quotient of 8 & 8? 3.if d average(arithmetic mean)of 25,31 and x is 3.value of x?

70. MATH

21x^3+67x^2-36=0 solutins

71. physics

can you please explain how the process of doping is conducted.

72. math

F(x)=x^2-2x-3 plz help me slove this ?

73. algebra

I having serious problems trying to solve this equation please help me find the product matrix for this input-output and demand matrices A= [ 0.1 0.03] D=  [ 0.07 0.6] 

74. Language arts

If you had to write a creative story what would it be about?

75. Math

I'm extemely lost at some point, how do you solve this equation by using the inverse of the coefficient matrix and by echelon method -x-8y=12 3x+24y=-36

76. Art and Creative development for Young children

Portfolios are a collaborative effort in that

77. Math

F(x)=x^2-2x-3 plz help me slove this ? HELP ME I DO NOT UNDERSTAND THIS HELP ME PLZ

78. Math

Is: n^2-9n+9 a perfect square??