# sasha

Popular questions and responses by sasha
1. ## Algebra

If 18g of a radioactive substance are present initially and 8 yr later only 9 g remain, how much of the substance will be present after 20 yr?

2. ## PHYSICS

a child sitting 1.10 m from the center of a merry go round moves with a speed of 1.25 m/s. calculate the centripetal acceleration of the child and the net horizontal force exerted on the child (mass = 25 kg).

3. ## Social Studies

What was the purpose of washington’s neutrality proclamation?

4. ## physics

21.7 kg child descends a slide 3.5 m high and reaches the bottom with a speed of 2.2 m/s How many joules of thermal energy are created due to friction as a kid slides down a slide?

5. ## Organic Chemistry

Simple Distillation: What is the molar composition of the vapor in equilibrium with a boiling liquid that has a composition of 60% A and 40% B? I know that the vapor should be richer in the lower-boiling substance, which is A in this case. And: If a sample

6. ## physics

A sports car of mass 950kg (including the driver) crosses the rounded top of a hill (radius = 95m) at 22m/s. Determine a) the normal force exerted by the road on the car, b) the normal force exerted by the car on the 72kg driver, and c) the car speed at

7. ## Physics

A 3800 kg open railroad car coasts along with a constant speed of 8.60 m/s on a level track. Snow begins to fall vertically and fills the car at a rate of 3.50 kg/min. ignoring friction with the tracks what is the speed of the car after 90.0 minutes?

8. ## physics

A yo-yo is made of two solid cylindrical disks, each of mass 0.053 kg and diameter 0.073 m, joined by a (concentric) thin solid cylindrical hub of mass 0.0052 kg and diameter 0.012 m. Use conservation of energy to calculate the linear speed of the yo-yo

9. ## chemistry -check over work

Naphthalene (C10H8)is a solid aromatic compound often sold as mothballs.The complete combustion of this substance to yield CO2(g)and H2O(l)at 25 ْC yields -5154 kJ/mol. A. write balanced equation for the combustion of C10H8. C10H8+12O2->10CO2+4H2O ΔH

10. ## Math

A basketball player made 63 out of 100 attempted free throws.What percent of free throws did the player make

11. ## Re post water in tanks problem

A./_\ B.\_/ C.|_| The three tanks shown above are filled with water to an equal depth. All the tanks have an equal height. Tank A has the greatest surface area at the bottom, tank B the least and tank C the middle. (Select T-True, F-False, G-Greater than,

12. ## physics

A boy throws a rock with an initial velocity of 2.47 m/s at 30.0 degrees above the horizontal. How long does it take for the rock to reach the maximum height of its trajectory?

The term 'human resources' refers to: (A)persons available for productive and professional services (B)raw materials used in the manufacture of goods (C)materials and goods made by human beings (D)capital invested by shareholders in company

14. ## algebra

use the integer to represent a withdrawal of \$125 from a bank account. ( i need help )

15. ## PHYSICS

A long solenoid that has 1200 turns uniformly distributed over a length of 0.37 m is required to produce a magnetic field of magnitude 0.02mT at its center. what voltage should be applied across the solenoid if it has a resistance of 20ohms? can someone

16. ## algebra

A boat can travel 38 mph in still water. If the boat can travel 100 miles with the current in the same time it can travel 80 miles against the current, find the rate of the current r in miles per hour.

17. ## physics

a .45kg ball, attached to the end of a horizontal cord, is rotated in a circle of radius 1.3m on a frictionless horizontal surface. if the cord will break when the tension in it exceeds 75 N, what is the maximum speed the ball can have?

18. ## Psychology

how does top-down processing leave us vulnerable to illusions?

19. ## Psychology Stats and Research

Although there is a popular belief that herbal remedies such as Ginkgo biloba and Ginseng may improve learning and memory in healthy adults, these effects are usually not supported by well-controlled research (Persson, Bringlov, Nilsson, and Nyberg, 2004).

20. ## health

Positive energy balance is important when A. weight loss is desired. B. you're stressed. C. weight stability is desired. D. a child is growing is it c ?

21. ## Organic Chemistry

Why is methylene chloride (dichloromethane) used to extract eugenol from cloves, and not toluene?

22. ## riddle

20 pigeons sat on the branches of a tree. A man hit 1 pigeon with a cannon. How many were left on the tree?

23. ## Math

1) Which expression represents the perimeter of the triangle drawn below? The triangle has (x-1) on the left side. (x+2) is on the bottom of the triangle. (2x-4) is on the slanted top. A) 3x-3 B) 3x-5 C) 4x-3 D) 4x-5 I do not know how to do this, so help

24. ## science

1) How do decomposers increase the fertility of soil? A) By storing moisture in the soil. B) By breaking down and digesting the remains of dead organisms. C) By making spaces for air and water. D) By burrowing deep below topsoil. I am thinking is is either

25. ## math

K is the midpoint of JL JL=4x-2 and JK=7. find x, KL, and JL. Very confused , can you please show steps to working out the problem

26. ## physics

In college softball, the distance from the pitcher's mound to the batter is 43 feet.If the ball leaves the bat at 110 mph, how much time elapses between the hit and the ball reaching the pitcher?

27. ## Physics

An elevator cable breaks when a 950 kg elevator is 23 m above a huge spring (k = 2.3×105 N/m) at the bottom of the shaft. (a)Calculate the work done by gravity on the elevator before it hits the spring. (b) Calculate the speed of the elevator just before

28. ## college

After you work out at the gym on a stationary bike for 43.0 minutes, the distance guage indicated that you have traveled 14.8 miles. What was your rate in km/hr?

29. ## Physics

A charge Q = -610 NC (-6.1 × 10^-7 C) is uniformly distributed on a ring of 2.4-m radius. A point charge q = +480 nC (+4.8 × 10^-7 C) is fixed at the center of the ring, as shown in the figure. An electron is projected from infinity toward the ring along

30. ## graphing help?

Graph ​ g(t)=4sin(3t)+2 ​. Use 3.14 for π . Use the sine tool to graph the function. The first point must be on the midline and the second point must be a maximum or minimum value on the graph closest to the first point. How would I graph this? I have

31. ## Math

m∠2 + m∠3 + m∠4 = 180°/ reason: Given? m∠1 + m∠2 = 180°/reason: Supplementary Angle definition m∠1 + m∠2 = m∠2 + m∠3 + m∠4/reason: Substitution property equality m∠1 + m∠2 - m∠2 = m∠2 + m∠3 + m∠4 -m∠2/reason= Subtraction

32. ## MATH

Sketch a rough graph of the yield of a crop as a function of the amount of fertilizer used.

33. ## Organic Chemistry

When reading an infrared (IR) spectrum for an unknown compound, you check for certain functional groups in a certain order. If C=O is absent, you check for alcohols/phenols (-OH), then for amines (N-H), then for ethers (C-O, & the absence of -OH). So, I

34. ## Physics

Find x and y components of a vector which is 10 units in length and 40 degrees below the +x axis. I honestly don't even know how to begin this problem .. Please help me !

35. ## statistic

A survey of drivers in the United States found that 15% never use a cell phone while driving. Suppose that drivers arrive at random at an auto inspection station. a. If the inspector checks 10 drivers, what is the probability that at least one driver never

36. ## Physics

A./_\ B.\_/ C.|_| The three tanks shown above are filled with water to an equal depth. All the tanks have an equal height. Tank A has the greatest surface area at the bottom, tank B the least and tank C the middle. (Select T-True, F-False, G-Greater than,

37. ## English

Does what we watch and experience in popular culture affect the way our families behave? Explain your rationale.

38. ## physics

two identical point charges are fixed to diagonally opposite corners of a square that is .5m on a side. Ecah charge is +3.0x10^-6 C. How much work is done by the elctric force as one of the charges moves to an empty corner

39. ## Algebra

Two cities are 5 1/2 inches apart on a map. The actual distance between the cities is 66 miles. What scale was used to draw the map?

40. ## calculus

A. find y' by implicit differentiation. B. solve th equation explicitly for y and differentiate to get y' in terms of x. cos (x) + √y = 5

41. ## calculus

If f(x) = sec x, find f''(π/4).

42. ## Physics

A football coach sits on a sled while two of his players build their strength by dragging the sled across the field with ropes. The friction force on the sled is 800 N and the angle between the two ropes is 20°. How hard must each player pull to drag the

43. ## math

Edna and Nancy leave the house of a common friend at the same time and walk for 4 hours. Edna walks due east at the average rate of 4 kilometers per hour and Nancy walks due north at the average rate of 3 kilometers per hour. What is the straight-line

44. ## algebra

what is the slope of y=3x-1 I think it's 4 can someone help me?

45. ## Math 20

Rebels launch a cannonball from a 58.8ft tall cliff toward their enemy's ship. The cannonball travels 19.6ft per second (ft/s). The equation for the cannonball's height, h, at time, t, after launch is h(t) = -4.9t^2 + 19.6t + 58.8, where h is in feet and t

46. ## math

A leak in a water tank causes the water level to decrease by 3.6×10^−2 millimeters each second. About how many millimeters does the water level in the tank decrease in 5 hours, or 1.8×10^4 seconds? express the answer in scientific notation.

47. ## math

A leak in a water tank causes the water level to decrease by 3.6×10^−2 millimeters each second. About how many millimeters does the water level in the tank decrease in 5 hours, or 1.8×10^4 seconds? express the answer in scientific notation.

48. ## PHYSICS

Magnetic field is 0.5T, radius is r=1m, current in one loop is I=2A. the angle between the magnetic moment and the external B field is 30 degrees. calculate the magnitude of the magnetic torque. so i know that torque= IANBsin(30) torque=

49. ## PHYSICS

The output voltage of AC source is V(t) = (25V)sin(5πt). what is the rms value of the voltage? answer: 18V, but how???

50. ## Math

you mix 2/5 cup of red paint for every 1/4 cup of blue paint to makw 1 5/8 gallons of purple paint. how much red paint and blue paint do u use

51. ## Algebra 1

Simplify -(2xy^3)^-5 A: -32x^5y^15 B: -32/x^5y^15 C: -1/32x^5y^15 D: -1/32x^4y^2 I have a good understanding of Exponents, its just that I don't get this one. I feel like it is C but at the same time I feel like it is B. I got C though but I don't

52. ## chemistry

what is the % (m/m) of Mg(NO3)2 in solution when 0.84 g of Mg(NO3)2 are dissolved in enough deionized water to prepare 500.0 ml of solution ( assume the solution in dilute enough that the density of the solution is 1.0 g/ml)

53. ## math

m∠2 + m∠3 + m∠4 = 180°/ reason: Given? m∠1 + m∠2 = 180°/reason: Supplementary Angle definition m∠1 + m∠2 = m∠2 + m∠3 + m∠4/reason: Substitution property equality m∠1 + m∠2 - m∠2 = m∠2 + m∠3 + m∠4 -m∠2/reason= Subtraction

54. ## math

4. Thomas is at a store buying school clothes. T-shirts are on sale for \$13 each and jeans are on sale for \$18 each. a) Write an equation that represents the total cost for x T-shirts and y pairs of jeans. I need help with a.. b) Thomas bought six T-shirts

55. ## Math *corrected myself*

he table shows the population of a school for the years 1992-2008. Year: 1992, 1994 1996, 1998, 2000, 2002, 2004, 2006, 2008 Population: 628, 656, 692,751, 793, 840 ,868, 902, 940 Which is the best prediction for the population in 2012? 1500 1100< or 1500

56. ## Chemistry

You have a tank of wine that needs a 20 ppm addition of SO2. Answer the following questions. 1. To make 5 gallons of a 6% w/v SO2 solution (expressed as SO2) how much K2S2O5 (222 g/mol) should be weighed out? 2. How much of this solution (in mLs) should be

57. ## language arts

What statement in the passage weakens the argument that personal music players cause hearing loss? Experts say more research is needed to prove a definite link between portable music and DVD players and hearing loss. Twenty-nine percent of students

58. ## Organic Chemistry

What is the solubility, in mg/mL, of a 50% water/50% methanol solution at 73.5 degrees Celsius? Is there a table available online somewhere?

59. ## Organic Chemistry

I spotted a commercial TLC plate, coated with silica gel, with a pure benzoin solution. After running the TLC plate in methylene chloride, the benzoin separated into two different spots. Rf values are 0.6 and 0.9. What explains this? A pure material should

60. ## Organic Chemistry

I have already calculated the volume of ethyl alcohol need to dissolve 0.300 g of sulfanilamide at 78 degrees Celsius. I got 1.429 mL ethyl alcohol. My question is: how do I calculate how many grams of sulfanilamide will remain dissolved in the mother

The temperature of an enclosure for a pet snake should be about 27°C, give or take 3°C. (show your work) a) What absolute value expression can be used to represent this situation? b) Use the expression to determine the temperature range the enclosure

62. ## Math

The temperature of an enclosure for a pet snake should be about 27°C, give or take 3°C. (show your work) a) What absolute value expression can be used to represent this situation? b) Use the expression to determine the temperature range the enclosure

63. ## Math

How many real number solutions does the equation have? y=3x^2-5x-5 A)one solution B)two solutions C)no solutions D)infinitely many solutions I can't figure this question out. Any help would be amazing.

Since the opening night, attendance at Play A has increased steadily, while attendance at Play B first rose and then fell. Equations modeling the daily attendance y at each play are shown below, where x is the number of days since the opening night. On

1)What is the simplified form of the expression? 5d^6*d^-12? A)5d^-72 B)6d^-72 C)5d^-6**** D)6d^-6 I think that the answer is C. If anyone could tell me if I am correct that would be great.

66. ## Physics Honors

A 47.0 g golf ball is driven from the tee with an initial speed of 48.0 m/s and rises to a height of 23.2 m. (a) Neglect air resistance and determine the kinetic energy of the ball at its highest point. (b) What is its speed when it is 8.0 m below its

67. ## Physics Honors

A basketball player makes a jump shot. The 0.600-kg ball is released at a height of 1.90 m above the floor with a speed of 7.40 m/s. The ball goes through the net 3.10 m above the floor at a speed of 4.40 m/s. What is the work done on the ball by air

68. ## chemistry

The enthalpy change for the reaction below at 25oC is -2,252 kJ (per mole of C11H24). What is the internal energy change for the reaction at 25oC? 11 CO(g) + 23 H2(g) --> C11H24(l) + 11 H2O(l)

69. ## Early Childhood Education

When designing IFSP objectives, its useful to parents to think of skills that a. are short and easy. b. fit into natural daily routines. c. are most useful in promoting ambulation. d. are taught in isolation to maximize chances of progress.

70. ## math

1. The world population in 1992 is 5.42 billion. If its population doubled every a. 41 years, what would its population be in 41 years? b. 41 years, what would its population be in 82 years? c. 82 years, what would its population be in 164 years?

71. ## math

The area covered by water lilies in a pond you own doubles in size every day. If allowed to grow the plants would cover the entire pond surface in 30 days. You had decided to do nothing until the pond is ½ covered. a. On what day will the pond be ½

72. ## chemistry

A 20.9 g sample of nitrogen gas combines completely with 4.5 g of hydrogen gas to form ammonia. What is the mass of ammonia formed? A 12.7 g sample of X combines with a 24.4 g sample of Y to form the compound XY2. What is the mass of the reactants?

73. ## algebra 2

A rubber ball is thrown 20 feet into the air. If it rebounds 3/5 of the height, how far will it have traveled after the fifth bounce?

74. ## Biology

Consider this pathway: signaling ligand ¨ G protein-coupled receptor ¨ G protein ¨ adenylyl cyclase ¨ cAMP. Identify the second messenger. Answer: A)G protein B)GTP C)adenylyl cyclase D)cAMP

75. ## calculus optimization problem

by cutting away identical squares from each corner of a rectangular piece of cardboard and folding up the resulting flaps, an open box may be made. if the cardboard is 30 inches long and 14 inches wide find the dimensions of the box that will yield the

76. ## Social Studies

What are some importance and reasons for monuments and forts in guyana?

77. ## Computers

What are some computer work related disorders?

78. ## Science

What are 2 disadvantages and advantages of a free range or extensive system?

79. ## math

Reading readiness of preschoolers from an impoverished neighborhood (n=20) was measured using a standardized test. Nationally, the mean on this test for preschoolers is 30.9 with SD=2.08. A) Children below the 30th percentile (in the bottom 30%) are in

80. ## Music

List the elements of music.

81. ## Social Studies

Give a detailed acoount for all the events the Guyana national anthem wre used at.

82. ## Math

There are 10 sailboats in the harbor. Some of the boats have 2 sail & some of boats have 3 sails. If there are 24 sails visible on all of the boats, how many boats have 3 sails & how many boats have 2 sails?

83. ## Finance

28. Ag Silver Mining, Inc. has \$500,000 of earnings before interest and taxes at the year end. Interest expenses for the year were \$10,000. The firm expects to distribute \$100,000 in dividends. Calculate the earnings after taxes for the firm assuming a 40

84. ## Modern History

Hi I need help finding where this cartoon was originally published Its the LEV HAAS (Czech,1901-1983 "Do not trust him! The kulak is the most hardened enemy of socialism") one. Sorry I couldn't post the link. Thanks!

85. ## Physics

A bush baby, an African primate, is capable of leaping vertically to the remarkable height of 2.3 m. To jump this high, the bush baby accelerates over a distance of 0.16 m while extending the legs. The acceleration during the jump is approximately

86. ## Finance

Strategic Initiative I have chosen amazon store online as my company. I need to come up with an intro and conclusion i have the body of the paper. Within these 2 paragraphs i need to describe the relationship between strategic and financial planning. How

87. ## english

Using plurals and possessives. How can you write a sentence about storing financial information effectively and efficiently.

88. ## calculus

what is the equation of the tangent line to the curve x^3 + 2y^2 + 3xy = 6 at the point (1,1)?

89. ## Math

Tell whether the triangle with the given side is a right triangle;1.4 m,4.8 m,5m. Explain please.

90. ## Math

Tell whether the triangle with the given side is a right triangle;14mm, 19mm, 23mm

91. ## math

find the local maximum and minimum values of f using both the first and second derivative tests. which method do you prefer? f(x) = x/(x^2+4)

92. ## calculus

find the local maximum and minimum values of f using both the first and second derivative tests. which method do you prefer? f(x) = x/(x^2+4)

93. ## calculus

verify that the function satisfies the hypothesis of the mean value theorem on the given interval. then find all numbers c that satisfy the conclusion of the mean value theorem. f(x) = x/(x+2) , [1,4]

94. ## calculus

let f(x)= 2 - |2x-1|. Show that there is no value of c such that f(3)- f(0) = f'(c)(3-0). Why does this not contradict the mean value theorem.

95. ## calculus

prove that the function f(x) = (x^101)+(x^51)+x+1 has neither a local maximum nor a local minimum

96. ## Mathematics for Liberal Arts

Using a Standard deck of 52 cards, what is the probability of drawing four aces in a 5-card hand?

97. ## calculus

a spotlight on the ground shines on a wall 12 m away. if a man 2m tall walks from the spotlight toward the building at a speed of 1.6m/s, how fast is the length of his shadow on the building decreasing when he is 4m from the building?

98. ## math

A ladder 10 ft long rests against a vertical wall. let θ be the angle between the top of the ladder and the wall and let x be the distance from the bottom of the ladder to the wall. If the bottom of the ladder slides away from the wall, how fast does x

99. ## calculus

A ladder 10 ft long rests against a vertical wall. let θ be the angle between the top of the ladder and the wall and let x be the distance from the bottom of the ladder to the wall. If the bottom of the ladder slides away from the wall, how fast does x