1. Chemistry

    The half-life for the process 238 U --> 206 Pb is 4.5*10^9 yr. A mineral sample contains 66.0 mg of 238 U and 16.0 mg of 206Pb. What is the age of the mineral?
  2. Chemistry

    A sample of charcoal is found to have only 1/8th of Carbon-14. Half-life of Carbon-14 is 5730yrs, what is the age of the charcoal?
  3. pre-calculus

    An open box is made from a square piece of material 36 inches on a side by cutting equal squares from the corners and turning up the sides. Use your calculator to find the maximum volume this box can hold. I got the equation 4x^3-36x^2+1296x = V But when I
  4. Lang. Arts

    Read the following stanza from “Alone”: Lying, thinking Last night How to find my soul a home Where water is not thirsty And bread loaf is not stone I came up with one thing And I don’t believe I’m wrong That nobody, But nobody Can make it out here
  5. Quadratic Equations

    Ok, I am supposed to find out what the variables are by factoring and finding square roots. I couldn't find the right factors of a and c that added up to b in the equation (did that make sense?). Please help me find them! TYVM -5n+6n^2-4=0
  6. Physics - Torque

    Consider a rectangular block of mass 30kg, height= 3m, length = 2m. A force F is applied horizontally at the upper edge. The acceleration of gravity is 9.8 m/s^2. 1)What is the minimum force required to start to TIP the block? 2)What is the minimum
  7. physics

    A 10.0-g bullet is fired horizontally into a 101-g wooden block that is initially at rest on a frictionless horizontal surface and connected to a spring having spring constant 155 N/m. The bullet becomes embedded in the block. If the bullet-block system
  8. Physics- Elena please help!

    A 20.0 g bullet is fired horizontally into a 85 g wooden block that is initially at rest on a frictionless horizontal surface and connected to a spring having spring constant 156 N/m. The bullet becomes embedded in the block. The bullet block system
  9. College physics

    dockworker applies a constant horizontal force of 80.0N to a block of ice on a smooth horizontal floor. thhe block starts from rest and moves 11.0m in 5.00s. (a) what is the mass of the ice block? (b) if the work stops pushing at the end of the 5.00s, How
  10. Physics

    There a five positions (A=-10cm, B=-5cm, C=0cm, D=5cm, E=5cm). A block is at rest at location C when a student pulls it to position A. The student then releases the block and it begins to oscillate. Given the block has a mass of 2kg and the spring has a
  11. Physics

    A 11.0-g bullet is fired horizontally into a 101-g wooden block that is initially at rest on a frictionless horizontal surface and connected to a spring having spring constant 160 N/m. The bullet becomes embedded in the block. If the bullet-block system
  12. physics

    A 4.30 kg block is pushed along a floor by a constant applied force that is horizontal and has a magnitude of 43.0 N. The figure gives the block's speed v versus time t as the block moves along an x axis on the floor. The scale of the figure's vertical
  13. math

    Suppose that you were saving money over 5 years to use in a purchase later. You have $1000 to put in the savings. After surveying several banks for savings plans, you found these options. "A" stands for the amount you will have in the bank after x years. *
  14. Social Studies

    I need help I changed my journal entry and I am trying to find info on African Americans migration and some good websites and can't find enough info to write my journal entry. Thanks You should find this website helpful:
  15. Geometry

    The measure of an angle SUT is twice m<RUS. if m<RUS=(18x-8)degrees and m<TUS=(4x + 16) degrees. Find m<RUT. This is an acute angle. Please help. I have tried figuring this problem out a million and one ways. Thanks
  16. Trigo

    From the top of the mountain 30m. Above the sea level, the angle of depression of two ships lying in a vertical plane with a mountain top measure 28° and 23°. Find the distance between the ships.
  17. text structure

    People have used various methods to measure the depth of the ocean. Long ago sailors lowered a rope over the side of the ship. When the rope touched the bottom,they knew how deep the water was. Today scientists measure the depth of the water with an echo
  18. math

    triangle ABC is isoceles with segment AB congruent tp segment AC. Angle A is 50. The bisectors of angle B and angle C meet at D. Find the measure of angle BDC
  19. trig

    a central angle intercepts an arc on a circle equal in length to the diameter of the circle. find the measure, in radians, of the central angle.
  20. Algebra I

    The expression 2(l+w) may be used to find the perimeter of a rectangle. What are the length and width of a rectangle if the area is 13 1/2 square units and the length of one side is 1/5 the measure of the perimeter?
  21. Physics

    1.)A force of 250 is just sufficient to start a 50 kg steel trunk moving across a wooden floor. Find the coefficient of static friction. 2.) compute the acceleration of the block sliding down a 30 deg inclined plane if the coefficient of kinetic friction
  22. Math

    Marquis called several pizza places and was told the following prices for a large pizza: $10,$11,$8,$17,and $9. What are the mean and the median prices? Is one more useful than the other for describing the typical price? Explain. P.S. For the mean I got 11
  23. Earth science

    Review the 1906 Quake that hit San Francisco and answer the questions below. 1. San Francisco is found to have been constructed on several large strike-slip faults. If these faults become active, what specific type of damage (based on the type of fault
  24. Maths

    Hi I am really sorry I now people have already attempted to help me with this one already, however I am still not able to understand, I really have not done a lot of these equations and am struggling. I have put a little more information down this time,
  25. Obesity

    I am trying to find a research article that examines the prevalence of obesity amoungst elementary school children. However, I have to find a research article that is not useful and provides limited research analysis. All the articles I have encountered
  26. College Algebra

    The manufacturer of an energy drink spends $1.20 to make each drink and sells them for $3. The manufacturer also has fixed costs each month of $9000. A.Find the cost function C when x energy drinks are manufactured. C(x)= B. Find the revenue unction R when
  27. Socials

    This is a table: table 5-1: 1845 Census ______________________________________ Total population 223 054 ______________________________________ People living in cellars 40 000 ______________________________________ People living in crowded apartments 60 000
  28. Physic

    A 3.5 kg block is pushed along a horizontal floor by a force of magnitude 15 N at an angle è = 40° with the horizontal. The coefficient of kinetic friction between the block and the floor is 0.25. Calculate the magnitudes of (a) the frictional force on
  29. Physics 102 (College)

    I'm stuck on part B of this question: A system does 125 J of work on environment and gains 79 J of heat in the process. Find change in internal energy (delta U, abbreviated dU)of a. the system and b. the environment. A. Find dU of the system W = 125 J Q =
  30. Physics 102 (College)

    I'm stuck on part B of this question: A system does 125 J of work on environment and gains 79 J of heat in the process. Find change in internal energy (delta U, abbreviated dU)of a. the system and b. the environment. A. Find dU of the system W = 125 J Q =
  31. Physics

    A 1.10 kg} block of wood sits at the edge of a table, 0.790 m above the floor. A 1.10×10−2 kg} bullet moving horizontally with a speed of 725 m/s embeds itself within the block. What horizontal distance does the block cover before hitting the
  32. physics

    A 1.20- block of wood sits at the edge of a table, 0.720 above the floor. A 1.20×10−2- bullet moving horizontally with a speed of 750 embeds itself within the block. What horizontal distance does the block cover before hitting the ground?
  33. Math

    A person standing close to the edge on the top of a 160-foot building throws a baseball vertically upward. The quadratic function s(t) = -16t^2 +64t + 160 models the ball's height above the ground, s(t), in feet, t seconds after it was thrown. After how
  34. Physics

    The figure below shows block 1 of mass 0.200 kg sliding to the right over a frictionless elevated surface at a speed of 5.00 m/s. The block undergoes an elastic collision with stationary block 2, which is attached to a spring of spring constant 1208.5 N/m.
  35. math

    you find a sales receipt from a store that shows the total price as $40, and the total amount paid including sales tax as $42. a. Write an equation you can use to find the sales tax rate r. b. Can you use r to find the percent for the sales tax?
  36. Calulus

    Consider the function y = 2x^3-3x^2+9x+5. 1. Find where the function is increasing, where the function is decreasing, and calculate all relative extrema (local max and local min) 2. Find where the function is concave up, where the function is concave down,
  37. COLLEGE CALCULUS. HELP!

    i don't know how to start this problem. i don't like cos and sin. im so confuse. 1.f(x)=sin(sin(x)), find f'(x) 2.f(x)= 4sin^4x, find f'(x). this problem i couldn't find it in my math book. i never see it before. because of sin exponent 4 -->sin^4
  38. Physics

    Three blocks rest on a frictionless, horizontal table, with m1 = 9 kg and m3 = 16 kg. A horizontal force F = 104 N is applied to block 1, and the acceleration of all three blocks is found to be 3.3 m/s2. 1) Find m2 2)What is the normal force between 2 and
  39. Math

    a cylinder of wooden block has base radius 'r' cm height 'h' cm and a total surface area of 32pi cm^2 1)show that r^2+hr=16 2)given that its height is 4cm more than its base radius, find the value of 'r' and of 'h'
  40. physics

    A 16.3 kg block is dragged over a rough, horizontal surface by a constant force of 157 N acting at an angle of 35 degree above the horizontal. Find the work done by the 157 N force.
  41. math

    suppose x S f(t) dt= x^2 - 2x + 1. Find f(x). 1 S = integral and 1 = lower level, x = upper i don't understand what i'm supposed to find/what to do and i didn't make any typos.
  42. calculus

    Consider the following. y = (2x2 + 5)(x3 − 25x) at (5, 0) (a) At the indicated point, find the slope of the tangent line. (b) Find the instantaneous rate of change of the function.
  43. Math and Science 6th grade

    Hello! I need help to find a source where I can find the accurate weather of a week in July. I would very much appreciate a direct link to a website. Thanks!
  44. math

    Find the GCF of the numbers using an appropriate method. 84 and 126 Find the prime factorization of the number, and write it in exponent form. 198
  45. POLYNOMIALS

    I'm really sorry, i'm preparing for O levels, so i have a lot of maths questions to ask... please excuse me... Question: Find the value of k for which a-3b is a factor of a^4 - 7a^2b^2 + kb^4. Hence, factorise completely. How do i even find k??? Please
  46. Math

    Find a linear equation whose graph is the straight line with the given property. Through (5, 9) with slope 2 I can't find the correct answer. I don't know where I did wrong Thanks.
  47. math

    suppose x S f(t) dt= x^2 - 2x + 1. Find f(x). 1 S = integral and 1 = lower level, x = upper i don't understand what i'm supposed to find/what to do and i didn't make any typos.
  48. language art

    From the play "The Diary of Anne Frank" Examples of Dramatic Irony - Find 3 of them. Find the quote. Explain why it is ironic.
  49. algebrae

    joey and three of his friends go to the movies. Each ticket costs $7.25. Write an algebraic expression to find to find the total cost of the tickets.
  50. Read and Write

    On my homework I have to put what kind of government that Columbus Indiana has. Can anyone direct me to a website where I could find this information. I have googled and can not find it.
  51. Math

    Need to find equation for 1250=1200+4-375. Is this possible or impossible. Need to find how to figure these type of questions. This is 3rd grade homework
  52. math

    1.)Name the property that is illustrated. a) 7 „e 6 ƒ­ 6 „e 7 b) 7 ƒy (1 ƒy 9) ƒ­ (7 ƒyƒn1) ƒy 9 2.) a) Identify the base in the following statement b) Solve for the amount. What is 81% of 285? 3.)a) Find the supplement of „£A. b) Find the
  53. mega urgently important maths

    the functions f and g are defined by f(x)=2/(x+1), x>0 g(x)=1-x^2, xER a)find value of fg(x)giving your answer in the simplest form. b) find f^-1(x) c) solve f(x)= f^-1(x)
  54. AP US history

    In the early 1700's, what problems did the Connecticut river valley colony have? and what disadvantages of the area did they find? I've been looking everywhere but this was after the Pequot war and I can't find anything. Thanks so much!
  55. college algebra

    given the functionf(x)=x^3+3x find the rateof change between the two stated values for x:1 to 2 find the equation of a secant line containig the given points (1,f(1))and (2,f(2))
  56. calculus

    Find an equation of the tangent line to the curve at the given point. y= (1+3x)^12 , (0,1) and find y' and y" y=cos(x^2) I got y' = -2xsin(x^2) i keep trying to get double prime but everything i try isnt working.
  57. marine science

    I have to find the type of organisms that the Black alder (plant) competes with or will displace. I have been googling this forever but I still cannot find the answer. Can someone please help!! Thanks
  58. social studies

    Find me a site for this sentence: a project in which canadians are providing aid in the area of health care or education. I can't seem to find one
  59. calculus

    x^2 + y^2 = 25 3x + y = 15 Find the two points of intersection. I don't just want the answer, if you could tell me how to find it, it would save my life. The sqaure root is making it really hard for me to understand.
  60. random

    why cant I find a question that I posted earlier? I find it but when I click on it it takes me back to the list of questions asked today, but mine is not there! WHY?
  61. physics

    Here is a problem: If i have a wire that is 75.0cm long and 0.550 mm in diameter and it has a 25 kg weight attached. I am trying to find stress and i have the area but I do not know how to find the force?
  62. math

    can someone please help me with this question. Given the funtion f(x)= 3x-9 a. find the rate of change between the two stated values for x: 7 to 8 b. find the equation of a secant line containing the given points: (7,f(7)) and (8,f(8)) I think I have
  63. physics

    A solenoid of radius 2.30 cm has 380 turns and a length of 15.0 cm. (a) Find its inductance. (b) Find the rate at which current must change through it to produce an emf of 76.0 µV
  64. summery

    my teacher told me to find something funny about brooklyn. i spent 2 1/2 hours in looking for it but couldn't find anything. plssssssssssss u must help me im getting tierd of looking at the computer screen.
  65. 6grademath

    Pattern of increasing perfect squares is shown25,36-----64,81,100,what is needed to square to find the missing term,5,6,7,8.....how do I find the answer.
  66. Business

    Soi had to find out what inventory valuation method Cineplex uses for an assignment, but I searched their annual reports continuously and I cannot find an answer, does anyone know?
  67. math

    1)Find a1 in a geometric series for which Sn=300,r=-3,and n=4 A)15 B)15/2 C)-15 D)1/15 I chose A 5)Find the fifth term of the sequence in which a1=-3,and aN+1=3aN-n A)-301 B)-99 C)-193 D)-341 I don't know
  68. Calculus-PLZ help!

    Given u=3i-2j+k,v=2i-4j-3k, w=-i+2j+2k, 1 Find a unit vector normal to the plane containing v and w. 2 Find the volume of the parallelepiped formed by u, v, and w. 3 Are any of these vectors parallel? Orthogonal? Why or why not?
  69. Chemistry

    A solution has a pH of 3.90. What is the hydroxide ion concentration? I know that I need to find H30+ first but my teacher doesn't allow calculators on the test. So how would I find the answer WITHOUT a calculator?
  70. math

    Let S be the part of the sphere x^2 + y^2 + z^2 = 25 that lies above the plane z = 4. Let S have constant density k. (a) Find the center of mass. (b) Find the moment of inertia about the z-axis.
  71. MATH

    How can I find the vertex, axis of symmetry? I know to find x and y intercepts i use the quadratic formula. I am given the parabola y=x^2+6x+5 I do not want the answer.. Just please explain to me how to solve for it. what method do I use???
  72. math

    f(x)=12x^5+45x^4–80x^3+2 the question asks to find the inflection points but i don't seem to understand how to find this even by taking the second derivative.
  73. trig

    my question is find all angles of theta and 2pi whose reference angle is alpha = pi/12. Give exact answers. i cannot for the live of me find this
  74. calculusiii

    Let S be the part of the sphere x^2 + y^2 + z^2 = 25 that lies above the plane z = 4. Let S have constant density k. (a) Find the center of mass. (b) Find the moment of inertia about the z-axis.
  75. calculs

    Find the volume when the plane area bounded by y=-x^2-3x+6 and x+y-3=0 is revolved about (1) x=3 and (2) about y=o B. Find the volu6 of focus generated by revolving the circule x^2+y^2=4 about the line x=3
  76. Math (Business)

    Find the value of the ordinary annuity at the end of the indicated time period. The payment​ R, frequency of deposits m​ (which is the same as the frequency of​ compounding), annual interest rate​ r, and time period t are given. amount ​1,000​;
  77. java/programming

    ask the user to enter his or her birthday in the MM/DD/YYYY format and output the number of days between the birthday and today. This gives the person's age in days.
  78. please give me a site or answer!!!!

    description of the population statistics LOCATION in South Carolina already found the age and race just having trouble with the location statistics please help!!!!!!
  79. biology

    some people in old age complain of stiff joints. what is the possible reason for it? please help, need answer related to bones and joints, level middle school biology
  80. science

    As redioactive material decays and the percentage of new material in the original sample increases, does the age of the sample substance increase, decrease, or remain the same?
  81. nuclear physics

    Calculate the age of a plant sample that shows about one-eighth of the carbon 14 of a living sample. The half-life of carbon 14 is about 5760a How do you do this?
  82. The practice of working with school age children

    A _______-centered program is most helpful to the children served. A. school B. parent C. child D. family C.
  83. The practice of working with school age children

    What of these is most likely to foster a nurturing environment? A. Caregiver-responsive B. Child-responsive C. Adult-responsive D. Parent-responsive B.
  84. health

    what should be the average weight of a 13 year old person who's height is 5 feet? can anyone give me sites which will help figure these kind of questions out? (weight according to height and age) Thanks -MC
  85. Stats

    1. The question asks to choose a data point in our graph (we chose 476,44) of median home prices (x) and percentage of students who scored Advanced on math MCAS (y). We have to find the residual. I'm confused because the equation I was given is e=y-yhat I
  86. Stats

    1. The question asks to choose a data point in our graph (we chose 476,44) of median home prices (x) and percentage of students who scored Advanced on math MCAS (y). We have to find the residual. I'm confused because the equation I was given is e=y-yhat I
  87. Algebra

    42. Which number best represents this set of data: 5, 5, 5, 6, 5, 5, 5, 6, 200? a. mean b. median I don't really understand this question but I'm guessing it's B.. 46. After flipping 13 consecutive "heads" on a fair coin, what is the probability of
  88. Statistics

    In an editorial, the Poughkeepsie Journal printed this statement: "The median price--the price exactly in between the highest and lowest--..." Does that statement correctly describe the median? Why or why not?
  89. The practice of working with school age children

    Which of the following are the major determinants of physical growth and development? A. Food, TV, and technology B. Heredity, parents, and school C. Intelligence, cleanliness, and aggression D. Nutrition, emotional well-being, and culture D.
  90. Sociology

    give an example of a current technology of the post-industrial era that is changing the way family might be structured. Given your experience in an online environment, can you predict what changes in the family unit might occur due to the information age?
  91. Theories and issues in working with school-age chi

    Parents, peers, media, teachers, and religious leaders are all examples of A. agents of socialization. B. moral virtue. C. recipients of socialization. D. internalized conversation B.
  92. World History

    a) Which technologies have been pivotal in the development of the Information Age? To what extent did the Industrial Revolution create the foundation for modern technologies? ~~~~~~~ Need help on that second part of the first question, I know I asked this
  93. Calculus

    Write a differential equation to model the situation given. Do not solve. Tests of an artifact discovered at the Debert site in Nova Scotia show that 28% of the original 14C is still present. What is the probable age of the artifact?
  94. spanish

    "¿A qué edad se casó tu hermana?" "Se casó _____." a. a las tres b. el cuatro de julio c. en la fiesta d. a los 22 años at what age ____ your sister? (what is the meaning of casó?)
  95. Help Please Stat-Math

    According to an airline, a particular flight is on time 75% of the time. Suppose 140 flights are randomly selected and the number of on time flights is recorded. Determine if you should use the Binomial model or Normal model to solve this problem. show
  96. Statistics

    One of the questions in the Pew Internet & American Life Project asked adults if they used the Internet, at least occasionally. The results showed that 454 out of 478 adults aged 18 - 29 answered yes; 741 out of 833 adults aged 30 – 49 answered yes; 1058
  97. Grammar

    11.The physician started to perform the operation, but the patient was not yet completely under anesthesia. a)Started to b)Perform c)Was not d)Completely under 12)Before his death at age 82, comedian Rodney Dangerfield’s motto was, “I
  98. ALGEBRA

    Find the amount of interest and the monthly payment for the loan. Purchase a car for $42,800 at 2.4% add-on rate for 5 years. (Round your answers to the nearest cent.)
  99. MATH

    Find the cost of a home in 20 years, assuming an annual inflation rate of 2%, if the present value of the house is $280,000. (Round your answer to the nearest cent.
  100. math

    Find the ending balance in an account that opens with $6,000, earns 6.5% interest compounded quarterly, and is held for 20 years. (Round your answer to the nearest cent.)