1. Biology (immune system)

    How does the immune system help maintain homeostasis? Help me please :(
  2. Solar system

    Why do objects in the solar system spin in the same direction?
  3. mat116

    consider the following system of equations y=3x-7 andy-3x=5 what can you conclude about the system of equations
  4. Math

    A restaurant has two fish tanks on display. One tank holds 625 liters of water while the other holds 312.5 liters. The smaller tank makes up which of the following percents of the larger tank? A) 5% B) 20% C) 50% D) 200%
  5. Math

    Mrs. Miller is planning a vacation overseas. She knows that fuel is sold in liters in other countries. She wants to become familiar with this measure of volume. Mrs. Miller just purchased 14 gallons of fuel for her car. About how many liters is this?
  6. english: critical thinking

    From the thirteenth to the sixteenth century, the Inca empire flourished in the Andes Mountains. It maintained an eleven-thousand-mile network of stone-paved roads. 1) Which of the following, if true, provides the strongest support for an archaeologist’s
  7. Math

    Trey can drive his car 130 miles on 4 gallons of gas. At this rate, how many miles can he drive on 6 gallons of gas?
  8. Math

    Trey can drive his car 130 miles on 4 gallons of gas. At this rate how far can Trey drive on 6 gallons of gas?
  9. Math

    Sally drives a car forty two miles and used 5 gallons of gas. How many miles can sally travel on 15 gallons of gas.
  10. Math

    Trey can drive his car 130 miles on 4 gallons of gas. At this rate, how far can Trey drive on 6 gallons of gas?
  11. Engineering Math, Newtons Cooling Method

    Newton's equation for a free falling object with air resistance of mass m kilograms says that its velocity v(t) satisfies the DE mv'(t) = mg - kv(t) where g = 9.8 \frac{m}{s^2} and v(t) is measured in \frac{m}{s}. Suppose that k=2 \frac{kg}{sec} and that a
  12. Government US

    The United States has two court systems, state and federal. The federal system a. has discretionary jurisdiction over all cases arising in the state system. c. is the only one based on the constitutional doctrine of the separation of powers. e. None of
  13. Physics

    Posted earlier but I wrote it incorrectly. How fast would a rocket have to be going in order to completely leave the solar system? (Assume that the Sun is the only mass in the solar system and that the rocket is beginning its journey from Earth's orbit?)
  14. Chemistry

    Calculate the molecular mass of the nonionic solutes. 8.02 grams of solute in 861 grams of water lower the freezing point to -0.430 celsius. the freezing point of H2O is lowered 1.86 celsius per mole of solute. the boiling point of H2O is raised 0.512
  15. Chemistry

    Question: A 0.400 g sample of propionic acid was dissolved in water to give 50.00 mL of solution. This solution was titrated with 0.150 M NaOH. what was the pH of the solution when the equivalence point was reached? I'm not really sure how i would go about
  16. Bio Chem

    What would the freezing point of water be if one prepared a 10 m solution of urea in water? (ÄTfp = 1.86°C/m x m)?
  17. Math

    Hi! I know I am asking a lot since this is a huge question, but I was wondering if anyone could help or walk me through it. I totally understand if you do not want to help. But I am really confused and any help at all would be amazing. Thank you! You are
  18. Math

    The ratio of milk to water in a container is 5:1 by volume. If the total volume of the mixture is 9 liters, find the volume of water in it.
  19. Math

    The ratio of milk to water in a container is 5:1 by volume. If the total volume of the mixture is 9 liters, find the volume of water in it.
  20. Math

    The ratio of milk to water in a container is 5:1 by volume. If the total volume of the mixture is 9 liters, find the volume of water in it.
  21. maths

    the ratio of milk to water in a container is 5:1 by volume.if the total volume of the mixture is 9 liters,find the volume of water in it.
  22. sociology

    Which of the following would be the best illustration of the expressive role in U.S. society, as developed by Talcott Parsons and Robert Bales? 1. A newly married woman keeps a spotless apartment and cooks beautiful gourmet meals. 2. On Saturday, Bill does
  23. Calculus

    A pulley system on a pier is used to pull boats towards the pier for docking. Suppose that a boat is being docked and has a rope attaching the boat's bow on one end and feeding through the pier's pulley system on the other end. The pulley system is 1 meter
  24. Chemistry (Inorganic)

    Given the two substances Sodium Nitrate (NaNO3) and Urea ([NO2]2CO), why is it that urea has a lower boiling point? I thought that the nitrate would because urea has the double bond which makes it more stable. Urea is covalently bonded. NaNO3 is an ionic
  25. Math/Biz Math

    I am so lost. Did I answer these problems right? Bud Ray is the owner of an automatic car wash located in a busy side of town. He currently has all the business he can handle and then some. His business has grown steadily over the years. His current car
  26. math

    Find the number of decibels for the power of the sound given. Round to the nearest decibel. A rocket engine, 2.37 x 10−5 (10 to the -5 power) watts/cm2(squared)
  27. Science

    you are a patent agent, an inventor comes to you claiming he has invented a self-powered engine that requires no fuel to run. will you agree to patent this invention? why or why not? use the first law of thermodynamics. can anyone help me out with this?
  28. algebra/what am I doing wrong Please help

    Solve the system by graphing. (If the system is inconsistent, enter INCONSISTENT. If the system is dependent, enter DEPENDENT.) 3x+2y=5 4x-3y=1 I have try dependent and inconsistent and either work. What am I doing wrong. Thank you
  29. CHEM

    A 0.552 g sample of ascorbic acid(Vitamin C) was dissolved in water to a total volume of 20.0 ml and titrated with 0.1103 M KOH. The equivalence point occurred at 28.42 ml. The pH of the solution at 10.0 ml of added base was 3.72. From this data, determine
  30. science

    Technician A and Technician B are examining the same substance. Technician A records the mass, volume, and weight of the substance and decides that it is sugar. Technician B records the melting point, density, and boiling point of the substance and decides
  31. science

    What are two chemical and two physical properties of water? Please help me. Thank you. physical properties: boiling point, freezing point,density, color, electrical conductivity chemical properties: reactivity with sodium. Reactivity and decomposition with
  32. Physics

    Calculate the work done on the system when 1.00 mol of gas held behind a piston expands irriversibly from a volume of 10.0dm^3 against an external pressure of 1.00 bar?
  33. math

    Basic unit of volume in the metric system; equal to 1.057 quarts. Is it A.centi- B.dec- C.gram D.liter E.meter F.milli-
  34. physics

    Water is circulating through a closed system of pipes in a two- floor apartment. On the first floor, the water has a gauge pressure of 3.4*10^5 Pa and a speed of 2.1 m/s. However, on the second floor, which is 4.0 m higher, the speed of the water is 3.7
  35. Physics

    A 2.0-kg piece of steel with a temperature of 70°C is submerged in 1.0 kg of water at 15°C. At what temperature does the water/metal system reach equilibrium? The specific heat of steel is 0.107 cal/(g × K)."
  36. Statistics

    According to insurance records a car with a certain protection system will be recovered 89% of the time. Find the probability that 3 of 7 stolen cars will be recovered.
  37. Statistics

    According to insurance records a car with a certain protection system will be recovered 90% of the time. Find the probability that 5 of 6 stolen cars will be recovered.
  38. chemistry

    A) A solution was prepared by dissolving 1.113 g of MgCl2 into water and made up to 50.0 ml, calculate the molar concentration of the solution. B) A 250.0 ml of 0.50 M solution of Na3PO2 solution was prepared by diluting 2.5 M of stock solution. Calculate
  39. Science Olympiad Examination

    Hello, Please give me some useful websites for the following subjects: Amphibians and Reptiles Bioprocess Reach for the stars(Astronomy) Disease Detectives Crave the wave Anatomy: Circulatory system, and nervouse system. The test is open book, and I want
  40. Social Studies

    The most useful indicator of degree of democracy reached by a particular society is whether it has a a) civilian government b) formal method whereby people can effect changes in government policy c) system of government checks and balances d) system of
  41. Social studies

    The most useful indicator of degree of democracy reached by a particular society is whether it has a a) civilian government b) formal method whereby people can effect changes in government policy c) system of government checks and balances d) system of
  42. Chemistry

    Help! I have to get this done tonight and I cannot get this answer right. A solution of water (Kf=1.86 ∘C/m) and glucose freezes at − 3.55 ∘C. What is the molal concentration of glucose in this solution? Assume that the freezing point of
  43. College Algebra

    Let x = the number of birds that Tim has. Let y = the number of dogs that Tim has. Tim has more than twice as many dogs as he has birds. Tim has more than 2 birds. The total number of dogs and birds that Tim has is less than 11. Set up an appropriate
  44. Chem

    Why does H2O + Sugar have a higher boiling point than Water? I said that H20 + Sugar has a solute of sugar which absorbs some of the heat when boiled. Is that correct?
  45. chemistry

    In a nickel bath with a total volume of 1000 gallons, titration of a 50 milliliter sample with 0.1 N silver nitrate used up 10.5 milliliters to the end point. What is the concentration in ounces per gallon of the nickel chloride (NiCl2 ) in the bath?
  46. sociology HS 2nd year

    What are some of the rules that the caste system imposes?Give me the ans in point ways.
  47. Information Technology

    I'm suppose to do Computer System Scenarios. There are 4 of them to do each asking to come up with IT solutions and I have no idea where to begin can someone point me in the right direction? Thanks
  48. Physics

    Find the potential energy of a system often point charges. 7nC and 2nC separated by 0.03m
  49. Physics

    Assume you have a rocket that requires a change in velocity of DeltaV=9.6km/s . There are two options for the propulsion system --- 1. chemical and 2. electric --- each with a different specific impulse. Using the setting of g0 =9.81m/s^2 to calculate the
  50. chemistry

    A piece of iron (Cp = 0.450 J/(gi°C)) that has a mass of 21.5 g and an initial temperature of 100.0°C is submerged in X g of water (Cp = 4.184 J/(gi°C)) at 20.0°C. The temperature of the system (iron and water) changes to 21.4°C. What is the value of
  51. Chemistry

    A piece of iron (Cp = 0.450 J/(gi°C)) that has a mass of 21.5 g and an initial temperature of 100.0°C is submerged in X g of water (Cp = 4.184 J/(gi°C)) at 20.0°C. The temperature of the system (iron and water) changes to 21.4°C. What is the value of
  52. physics

    The shock absorbers in the suspension system of a car are in such bad shape that they have no effect on the behavior of the springs attached to the axles. Each of the identical springs attached to the front axle supports 294 kg. A person pushes down on the
  53. physics

    The shock absorbers in the suspension system of a car are in such bad shape that they have no effect on the behavior of the springs attached to the axles. Each of the identical springs attached to the front axle supports 351 kg. A person pushes down on the
  54. physics

    The shock absorbers in the suspension system of a car are in such bad shape that they have no effect on the behavior of the springs attached to the axles. Each of the identical springs attached to the front axle supports 351 kg. A person pushes down on the
  55. physics

    The shock absorbers in the suspension system of a car are in such bad shape that they have no effect on the behavior of the springs attached to the axles. Each of the identical springs attached to the front axle supports 303 kg. A person pushes down on the
  56. physics need help plz

    An arrangement of two pulleys, as shown in the figure, is used to lift a 49.6-kg mass a distance of 3.70 m above the starting point. Assume the pulleys and rope are ideal and that all rope sections are essentially vertical. (a) What is the mechanical
  57. Math (Need help Urgent)

    1. Fireworks are to be launched from a platform at the base of a hill. Using the top of the platform as the origin and taking some measurements, it was determined that the cross-section of the slope of one side of the hill is y=4x-12 . If the path of the
  58. chemistry

    Explain each of the following observations in terms of the electronic strucutre and/ or bonding of the compunds involved. (a)At ordinary conditions, HF( normal boiling point=20C) is a liquid, whereas HCl(normal boiling point=-114C) is a gas. (b)Molecules
  59. Pre-algebra

    List two different equations for the following situation. Linda buys a new car. She travels 96 miles using 4 gallons of gasoline. Let m = the number of miles Lina travels. Let g = the number of gallons of gasoline she uses
  60. Algebra

    With a full tank of gas, if you can drive 465 miles, your car can go 18 miles per gallon. Write an equation to show how many miles (use m for miles) you can drive after using _____ gallons of gas (use g for gallons).
  61. Chem Lab Help

    Trial #1 Trial #2 Trial #3 Mass: gelatin capsule (g) .123 .118 .122 Mass: whole alka-seltzer tablet (g) 3.230 3.230 3.230 Mass: capsule + alka-seltzer sample (g) .822 .882 .677 Mass: system before reaction (g) 23.109 23.110 22.735 Mass system after
  62. Chemistry

    Which solution has the lower freezing point? 11.0 g of methanol in 100. g of water OR 22.0 g of ethanol in 200. g of water?
  63. physics

    Two cars approach an ice-covered intersection. One car, of mass 1.26 103 kg, is initially traveling north at 10.6 m/s. The other car, of mass 1.66 103 kg, is initially traveling east at 10.6 m/s. The cars reach the intersection at the same instant,
  64. chemistry

    10.0 mL of a Cu2+ solution of unknown concentration was placed in a 250 mL Erlenmeyer flask. An excess of KI solution was added. Indicator was added and the solution was diluted with H2O to a total volume of 75 mL. The solution was titrated with 0.20 M
  65. geometry

    a student makes a scale model of a large aquarium.Her model holds 5 liters of water.The large aquarium holds 5000 liters of water.By what factor can she multiply the dimensions of the model to get the demensions of the large aquarium?
  66. math

    Complete in Metric Conversions: What is the tip speed (ft/min) of a 21 inch long rotary lawn mower blade that is connected to the output shaft of an engine operating at 3400 rpm?
  67. intro chem HELp please

    1. Zinc is often used to calibrate calorimeters because it undergoes a very sharp phase transition from the solid to the liquid at 419.5oC. Calculate the enthalpy change when 5 g of zinc metal is heated from 100oC to the point where the entire sample is
  68. geometry

    The melting point of mercury is -36 degrees fahrenheit and its boiling point is 672 degrees fahrenheit what is the difference between the boiling points and the melting points
  69. algebra 2(check)

    1)Choose the correct description of the system of equations:2x+3y=10 and 4x+6y=20. I got consistent/dependent 2)The first equation of the system is multiplied by 2. By what number would you multiply the second equation to eliminate the x variable by
  70. World History (Ms. Sue)

    How did the French system of colonial rule differ from that of Great Britain? A: The French system of colonial rule differed from that of Great Britain in several ways. In Great Britain, the colonial rule was indirect, keeping the old African elite in
  71. math/algebra

    Can I get help in solving these problems using the linear system of elimination. 4x - 5y =22 x + 2y = -1 2x - 3y = 16 3x + 4y = 7 Word Problem: During the summer, you want to earn at least $150 per week. You earn $10 per hour working for a farmer and you
  72. physics

    In the (Figure 1) the coefficient of static friction between mass mA and the table is 0.42, whereas the coefficient of kinetic friction is 0.17. Ignore masses of the cord and the (frictionless) pulley. What minimum value of mA will keep the system from
  73. physics

    an atwood machine is set up with m1=234 grams and m2=485 grams. the height of m2 above the floor is 137 cm, and the system is released from rest. the pulley is frictionless. what is the acceleration of this system? what is the tension in the string? how
  74. chemistry

    A solution that holds the maximum amount of solute under the solution conditions is said to be
  75. math

    a local hardware store has a 10-gallon can of gray paint left over that is a mixture of 35% black paint and 65% white paint. how many gallons of white paint will be needed to make the gray mixture 20% black? note: answers must be 5 gallons, 7.5 gallons, 12
  76. college algebra need help asap

    Solve the system of equations using substitution. 2x−8y = 2 x+4y = 0 What is the solution? Select the correct choice below and fill in any answer boxes in your choice. A. m (Type an ordered pair.) B. There are infinitely many solutions.
  77. Algebra 2

    1. By graphing the system of constraints, find the values of x and y that maximize the objective function. 2<=x<=6 1<=y<=5 x+y<=8 maximum for p=3x+2y A. (2,1) B. (6,2) C. (2,5) D. (3,5) 2. By graphing the system of constraints, find the
  78. Math - Real number system

    Solve the following equation in the real number system. Please show all of your work. x^4 + 6x^3 + x^2 - 24x - 20 = 0 Help!!!!
  79. discrete math

    Consider the weighted voting system [q:5,3,1]. find the banzhaf power distributing of this weighted voting system when : q=5 and q=8
  80. Food Chemistry

    Calculate the amounts and pH values for preparing the following acetic acid/acetate buffer solution. 1.) In the first step, If you plan to prepare a 2.00 M sodium acetate in 200.0 mL distilled water, how many grams of sodium acetate should be added in
  81. physics

    a 9.0 g ice cube at -10 C is put into a thermos flask containing 100 cm^3 of water at 20 C. by how much has the entropy of the cube-water system changed when the equilibrium is reached? the specific heat of ice is 2220 J/kg K.
  82. Math/Management

    FuelMotion is an oil company that owns two oil processing plants that produce gasoline from crude oil. Their Georgia Plant produces 2 thousand gallons of premium, 1 thousand gallons of medium, and 6 thousand gallons of regular gasoline every day it
  83. Biology

    20. Three common characteristics of adult vertebrates are a. skull, notochord, and complex organ system b. backbone, segmentation, and open circulatory system c. two pairs of jointed appendages, cephalization, and internal skeleton d. hydrostatic skeleton,
  84. social studies

    the most useful indicator of the degree of democracy reached by a particukar society is whether it has a a) civilian goverment b) formal method whereby people caneffect changes in goverment policy c)system of government checks and balances d) system of
  85. Biology

    20. Three common characteristics of adult vertebrates are a. skull, notochord, and complex organ system b. backbone, segmentation, and open circulatory system c. two pairs of jointed appendages, cephalization, and internal skeleton d. hydrostatic skeleton,
  86. math again

    How does "How many gallons of a 12% indicator solution must be mixed with a 20% indicator solution to get 10 gal of a 14% solution?" turn into ".12x + .2(10+ -1x) = .14(10)"?? Please, I need to understand how it works! Thank you.
  87. chemistry

    Suppose a piece of lead with a mass of 14.9g at a temperature of 92.5c is dropped into an insulated container of water. The mass of water is 165g and its temperature before adding the lead is 20.0c. What is the final temperature of the system? The sum of
  88. algebra word problem

    My car gets 19 miles per gallon in the city and 34 miles per gallon on the highway. Suppose I used 12.857 gallons of gas and got an average of 27 miles per gallon for the trip. How many gallons did I use for each part of the trip? _____gallons at 19 miles
  89. Chemistry

    Sodium hypochlorite, NaClO, is added as a disinfectant to the water supply. You are analyzing a sample from the supplier to verify its purity and you prepare to titrate 250.0 mL of a solution containing 1.86 g of NaClO with a 1.00 M HCl solution. What is
  90. chemistry

    a sample of 20.0 mL of 0.100 M HCN (Ka=6.2*10^-10) is titrated with 0.150 M NaOH. a) what volume of NaOH is used in this titration to reach the equivalence point? b) What is the molar concentration of CN- at the equivalence point? c) What is the pH of the
  91. Biology

    20. Three common characteristics of adult vertebrates are a. skull, notochord, and complex organ system b. backbone, segmentation, and open circulatory system c. two pairs of jointed appendages, cephalization, and internal skeleton d. hydrostatic skeleton,
  92. Physics

    The boiling point of helium at 1 atm is 4.2 K. What is the volume occupied by helium gas due to evaporation of 70 g of liquid helium at 1 atm pressure and a temperature of 6.2 K?
  93. Chemistry

    Look up the boiling points and relative molecular masses of water, hexane, and ethanol. Try to explain the relative magnitudes of their boiling points in terms of polarity. I know that ethanol and water are polar and that hexane is non-polar. Also, 6)
  94. mechanics

    The figure below shows a ball with mass m = 0.299 kg attached to the end of a thin rod with length L = 0.388 m and negligible mass. The other end of the rod is pivoted so that the ball can move in a vertical circle. The rod is held horizontally as shown
  95. physics

    The amount of heat Q needed to turn a mass m of room temperature T_1 water into steam at 100degrees C T_2 can be found using the specific heat c of water and the heat of vaporization H_v of water at 1 atmosphere of pressure. Suppose that a commercial
  96. Algebra

    Company produces three models of speakers. models A,B,and C and can deliver them by truck, van and car. Truck holds 2 boxes of model A, 2 of model B and 3 of model C. Van holds 3 boxes of model A, 4 boxes of model B, and 2 boxes of model C The car holds 3
  97. Math

    On July 15,2009, the Nixon Car Company purchased 1,000 tires from the Harwell Company for $50 each. The terms for the sale were 2/10, n/30. Nixon uses a periodic inventory system and the net method of accounting for purchase discounts. 1. prepare the
  98. USA PoliScience

    In forming Medicare, a. President Johnson allowed conservatives to propose a program, knowing it would ensure passage by Congress. > This is probably not correct because congress was never so easy. b. President Johnson resisted some Democratic urging to
  99. Computer Science

    How would I put this into one program? These are the directions: Write a method that takes two parameters. If the first parameter is equal to second parameter. Multiply both and print result. If the first parameter is less than the second parameter, add
  100. Science

    I have some equations that I would like checked. Thanxs! 1. An automobile starts from rest and accelerates at 3m/s2 for 4 seconds. How fast is it going after acceleration? 3m/s^2 / 4 = .75 m/s 2. If an automobile travels at 30 km/hr. for 2 hours, how far