Tanya

Most popular questions and responses by Tanya
1. history

the reign of terror was a necessary evil discuss

2. CHEMISTRY

At 25°C and 730 mm pressure,380 ml of dry oxygen was collected.If the temperature is constant ,what volume will the oxygen occupy at 760 mm pressure ? ANSWER- 365ml

3. math

The scale of the map is missing.The actual distance from Liberty to West Quall is 72 miles,and it is 6 inches on the map. (A)What is the scale of the map? (B)Foston is between Liberty and West Quall and is 4 inches from Liberty on the map.How far is Foston

4. Chemistry

0.24g of a volatile substance,upon vaporisation,gives 45ml vapour at NTP what will be the vapour density of the substance?

5. CHEMISTRY HELP !!!!

NH4CL , ZNCL2 , KAL(SO4)2 FIND THE FOLLOWING NET IONIC EQUATION FOR HYDROLYSIS EXPRESSION FOR EQUILIBRIUM CONSTANT (KA OR KB) VALUE THANK YOU SO MUCH!!!

6. chemistry

how much heat is required to vaporize 343g of liquid ethanol at its boiling point?

7. Chemistry

Hydrazene can be used in fuel cell N2H4(aq)+o2(g)->N2(g)+2H2O(l) IfΔG°for this reaction is -600kj what will be the E°for the cell?

8. statistics

The ages of commercial aircraft are normally distributed with a mean of 13.0 years and a standard deviation of 7.5 years what percentage of individual aircraft have ages greater than 15 years assume that a random sample of 49 aircraft is selected and the

i have no idea! The real estate assessor for a country government wants to study various characteristics of single family houses in the country. A random sample of 70 houses reveals the following: the mean is 1759, standard deviation is 380 and 42 houses

10. Chemistry

Exactly 100 mL of 0.14 M nitrous acid (HNO2) are titrated with a 0.14 M NaOH solution. Calculate the pH for the following. (a) the initial solution (b) the point at which 80 mL of the base has been added (c) the equivalence point (d) the point at which 105

11. Calculus

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. Sketch the

12. physics

a sled slides down a frictionless hill. if the sled starts from rest at the top, its speed is 7.5 m/s. a.) on a second run , the sled starts with a speed of 1.5 m/s at the top.. will it end with less than 9 m/s, 9 m/s, or more than 9 m/s b.) find the speed

13. chemistry

A|A+3(0.1)||B+2(0.01m)|B GIVEN E°A|A+3=0.75v E°B|B+2=0.45v

In a murder investigation, the temperature of the corpse was 32.5 C at 1:30pm and 30.3 C an hour later. Normal body temperature is 37.0 C and the temperature of the surrounding was 20.0 C. When did the murder take place? PLEASE SHOW STEP BY STEP

15. Physics Help Please --- Urgent

A thin converging lens is found to form an image of a distant building 24 cm from the lens. If an insect is now placed 16 cm from this lens, how far FROM THE INSECT will its image be formed? A) 64 cm B) 72 cm C) 32 cm D) 96 cm E) 48 cm

16. CHEMISTRY

A gaseous mixture was prepared by taking equal mole of CO and N2 .if the total pressure of the mixture was found 1 atmosphere ,the partial pressure of nitrogen (N2) in the mixture is.

17. Chemistry

For the reaction shown, compute the theoretical yield of the product in grams for each of the following initial amounts of reactancts 2Al(s) + 3Cl2(g) = 2AlCl3(s)

18. Algebra

Use the formula h= -16t^2+250t to model the height 'h' in feet of a model rocket 't' seconds after it has luanched. Determine when the rocket will reach a height of 900 feet.

19. math

A water heater has a diameter of 18 inches. It sits in a drain pan that has a diameter of 22 inches and a height of 2 inches, as modeled in the diagram below. Water that leaks out of the water heater sits in the drain pan. Which of the following is closest

20. High Point

a sign is in the shape of rhombus with a 60 degree angle and sides of 9cm long. Find its are to nearest tenth?

21. Chemistry :/

A 10.231-g sample of window cleaner containing ammonia was diluted with 39.466 mL of 0.1063 M HCl to reach the bromocresol green end point. Find the weight percent of NH3 (FM 17.031) in the cleaner.

22. calculus help

Evaluate!!!! integral -10 to 10 ((2e^x)/(sinhx+coshx))dx Thanks!

23. chemistry

For each of the following unbalanced equations, indicate how many moles of the first product are produced if 0.625 mol of the second product forms. State clearly the mole ratio used for each conversion. CH3CH2OH(l) + O2 --> CH3CHO(aq) + CH3CHO(aq) + H2O(l)

24. physics

a cylinder of diameter 1cm at 30degree celcius is to slid into a hole on a steel plate. the hole has a diameter of 0.9997 cm at 30 degree celcius. to what temperature must be the plate be heated when steel has the alpha 1.1X10^-5/degree celcius

25. statistics

In a recent​ season, the population standard deviation of the yards per carry for all running backs was 1.241.24. The yards per carry of 25 randomly selected running backs are shown below. Assume the yards per carry are normally distributed. 1.81.8

26. College Math 3

Lisa will rent a car for the weekend. She can choose one of two plans. The first plan has an initial fee of $53.98 and costs an additional$0.15 per mile driven. The second plan has an initial fee of $67.98 and costs an additional$0.10 per mile driven.

Breathing is cyclic and a full respiratory cycle from the beginning of inhalation to the end of exhalation takes about 3 s. The maximum rate of air flow into the lungs is about 0.3 L/s. This explains, in part, why the function f(t) = (3/10)sin(2πt/3) has

28. statistics

Breast feeding sometimes results in a temporary loss of bone mass as calcium is depleted in the mother's body to provide for milk production. An investigation gave the following data on total body bone mineral content (g) for a sample of mothers both

29. chemistry

In a zero order reaction ,20% of the reaction complete in 10s .How much time it will take to complete 50% of the reaction?

30. Physics Help Please --- Telescope

An astronomical refracting telescope is made from two lenses. the objective lens has a focal length of 114 cm, and the eyepiece lens has a focal length of 17 cm. a) What is the total length of the telescope? b) What is the angular magnification of the

40. Physics

Two spheres with masses of 5.00 g and 10. kg respectively are .500 m apart. calculate the force of attraction between them.

41. PHYSICS

A proton is traveling to the right at 231 km/s. It has a head-on perfectly elastic collision with a carbon atom. The mass of the carbon atom is 12 times the mass of the proton, what is the speed of proton after the collision?

42. physics

In introductory physics laboratories, a typical Cavendish balance for measuring the gravitational constant G uses lead spheres of masses 1.79 kg and 16.9 g whose centers are separated by 5.49 cm. Calculate the gravitational force between these spheres,

43. Physics

Which of the following is the correct relationship between the electric field strength and the potential difference?

44. verbal linear equations

a taxi costs $2.75 for the first quarter of a mile and$0.85 for each subsequent quarter mile.A ride that cost $23.15 is how many miles longer than a ride that costs$17.20?(please i don't want example show me how u work it out )

45. CHEMISTRY

Two gases A and B having the same volume diffuse through a porous in 20 and 10 seconds respectively .The molecular mass of A is 49u.Molecular mass of B will be

46. CHEMISTRY

The pressure exerted by 6.0g of methane gas in a 0.03m3 vessel at 129degreeC is.

47. physics

A model airplane of mass 0.7 kg is attached to a horizontal string and ﬂies in a horizontal circle of radius 5.6 m, making 1.6 revolutions every 7 s. (The weight of the plane is balanced by the upward “lift” force of the air on the wings of the

48. math

charlene takes the bus to work in the morning, then walks home for lunch, walks back to work, and finally walks home in the evening. The distance one way is 600 meters. How far does she walk each day between home and work? 1.2 kilometers 1.8 kilometers 180

49. chemistry

CHEMICAL KINETICS The rate of reaction 2N₂O5->4NO₂+O₂ can be written in three ways -d[N₂O5]/dt= k[N₂O5] d[NO₂]/dt= k'[N₂O5] d[O₂]/dt =k"[N₂O5] The relationship between k and k' and between k and k" are ?

50. Chemistry

Calculate whether or not a precipitate will form if 1.30 mL of 0.80 M NH3 are added to 2.2 L of 1.0 10-3 M FeSO4. Calculate Q.

51. Math

write the logarithmic equation in exponential form log0.001=-3

52. Chemistry

the rate of diffusion of a gas having molecular weight just double of hydrogen gas is 30 ml/s.the rate of diffusion of hydrogen gas will be

53. Stat help

An article claimed that the typical supermarket trip takes a mean of 22 minutes. suppose that in an effort to test this claim, you select a sample of 50 shoppers at a local supermarket. the mean shopping time for the sample of 50 shoppers is 25.36 min.

54. Science

water is flowing through a horizontal pipe of varying cross section at any two places the diameters of the tube are 4cm and 2cm if the pressure difference between these two places be equal to 4.5cm then determine the rate of flow of water in the tube

55. physics

A 2.5 kg mass weighs 23.75 N on the surface of a planet similar to Earth. The radius of this planet is roughly 7.7 × 10 6 m.Calculate the mass of of this planet. The value of the universal gravitational constant is 6.67259 × 10−11N · m2/kg2

56. CALCULUS

A plane, flying horizontally at an altitude of 1 km and a speed of 500 km/hr, passes directly over a radar station. find the rate in km/hr at which the distance from the plane to the station is changing when it is 2 km away from the radar station. Hint:

57. computers

What are contributing factors if you were in the market for commercial paper prior to a final purchase?

58. math

Given the expression (3s-4)(4s+5), explain in words the steps taken to completely simplify the expression

59. Maths

A survey conducted with 30 students revealed that:20 has cell phone 16 has tsblets 4 has neither 2x has both...calculate the value of x

60. American national government

In brown v board of education Yvette supreme court overturned purest v Ferguson because it concluded that

61. Physics

On a playground slide, a child has potential energy that decreases by 1000 \rm J while her kinetic energy increases by 900 \rm J. What other form of energy is involved, and how much?

62. help math

solve each of the following quadratic equation (1)x^2=5x+6 (2)x^2+9x=10

63. help in math

solve and check each of the following quadratic equation (1) x^2=6x (2) x^2=3x (3)x^2=17x (4) x^2=5x+6 (5) x^2+9x=10

solve and check each of the following quadratic equation (1)x^-9x=0 (2)x^+8x=0 (3)x^=6x (4)x^=-3x

65. computer programming

Design a program that asks the user to enter a nonegative integer and then display the factorial of that number- it can be a flowchart or pseucode

66. spanish

What is the tourism like in El Salvador? Thank you for using the Jiskha Homework Help Forum. Here are some sites for you to visit: 1. http://www.lonelyplanet.com/worldguide/destinations/central-america/el-salvador 2.

67. math

the distance between new york city and boston is 189.9 miles as the crow flies. how far is it in kilometers? 117.7 kilometers 305.7 kilometers 417.8 kilometers 1,899 kilometers

68. chemistry

The edge length of face centered unit cubic cell is 508pm.if the radius of the cation is 110 pm,the radius of anion is

69. physics

an elevator motor provides 45 W of power while lifting a 2000 kg elevator 35 m. if the elevator contains six passengers of the same mass and it takes 20.0 to accomplish this task, determine pass of each passenger.

70. Math

The perimeter of a square is f feet. How long in yards is each side of the square?

71. physics

In the design of a supermarket, there are to be several ramps connecting different parts of the store. Customers will have to push grocery carts up the ramps. A grocery cart has a mass of 30kg. The coefficient of friction is .10. Assume that the shoppers

72. chemistry

how many grams of hydrogen are produced if you have 120 grams of sodium? 2Na+2H2O->2NaOH+H2

91. Chemistry

You are using concentrated hydrochloric acid solution (12.0 M)to make 445.0 ml of a 5.85 M solution. Calculate the number of milliliters of concentrated HCl required to make the solution.

92. Math

Jake ate seven times more jelly beans as Sam. Together they ate 128 jelly beans. How many jelly beans did each person eat?

93. american government

Which of the following is characteristic of a capitalist economic system? a. free enterprise b.self-reliance c.private property d.individualism e.all of the answers are correct

94. Physics

if you were on a 22.7 degree slope and an avalanche started 425 m up the slope, how much time would you have to get out of the way, there is no friction.

95. algebra

find x and y 5x-3y=-4 3x+2y=9

96. physics

A 2.5 kg mass weighs 23.75 N on the surface of a planet similar to Earth. The radius of this planet is roughly 7.7 × 10^6 m. Calculate the mass of of this planet. The value of the universal gravitational constant is 6.67259 × 10^−11N · m2/kg2. Answer

97. spanish

do anyone have the answer for penn foster exam 38981200 part 4 comprehension

98. Finance

a corporation had year end 2004 and 2005 retained earnings balances of $320,000 and$400,000, respectively. The firm reported net profits after taxes of \$100,000 in 2005. the firm paid dividends in 2005 ofwhat

99. math - statistics

Football team makes in average 2 touchdowns per game. Use Poisson distribution to find probability that this team will make 5 touchdowns in the next 3 games (adjust ë) Tip: use Poisson Appendix Table or Excel function Poisson(x, ë, false) for x=5 and ë