Questions Asked on
March 25, 2017

  1. Chemistry

    Given ∆Hºrxn = -1670 kJ/mol for 2Al(s) + (3/2)O2(g) --> Al2O3(s), determine ∆Hº for the reaction 2Al2O3(s) --> 4Al(s) + 3O2(g). I flipped Al(s) + (3/2)O2(g) --> Al2O3(s) to Al2O3(s) --> A(g) + (3/2)O2(s) and multiplied the molar values by 2. I ended

    asked by Anon
  2. physics

    A block of mass m = 3.53 kg is attached to a spring which is resting on a horizontal frictionless table. The block is pushed into the spring, compressing it by 5.00 m, and is then released from rest. The spring begins to push the block back toward the

    asked by Anonymous
  3. physics

    A 30 ohm resistor is connected in parallel with a variable resistance R. The parallel combination is then connected in series with a 6 ohm resistor and connected across a 120 V source. Find the minimum value of R if the power taken by R is equal to the

    asked by Oscar
  4. physics

    At a playground, a 20-kg child sits on a spinning merry-go-round, as shown from above in (Figure 1) . The merry-go-round completes one revolution every 6.2 s, and the child sits at a radius of r=1.8m. a. What is the force of static friction acting on the

    asked by silvia
  5. Maths

    The 90 men that visited a restaurant take one of either pounded yam,rice and amala.10 take pounded yam and rice,19 take rice and amala and 29 take pounded yam and amala.x men take all the three menu.2x men each take only one food item.how many take all

    asked by Rilwan
  6. Chemistry

    Given H2(g) + (1/2)O2(g) --> H2O, ∆Hº = -286 kJ/mol, determine the standard enthalpy change for the reaction 2H2O(l) --> 2H2(g) + O2(g). Just checking... should end up with ∆Hº = 572 kJ/mol right??

    asked by Anon
  7. Physics

    A 10 kg mass is hung from 2 light, inextensible strings such that the vertical string is attached to the top of the block at an angle 60 degree and the other string is attached straight horizontally to the adjacent side of the mass. How do we solve the

    asked by Nisha
  8. Language Arts

    7. In which of these sentences is the meaning of the word unethical best expressed? A: Sarah felt bad seeing the child cry, so she bought him a candy bar B: Brady didn't have time to finish his paper, so he had a friend do it for him *** C: Rachel wanted

    asked by Love School
  9. pysics

    three identical point charges each Q coulombs are placed at the vertices of an equilatwral triangle 20cm apart.calculate the force on each charge

    asked by emmanuel
  10. Algebra

    Helen deposited $1200 at 5% interest compounded continuously. After 6 years, how much did she have ? I got $2,160 but I was told it was incorrect

    asked by Marryy
  11. Maths

    There are 9 counters in a bag. There is a number on each counter. 1, 1, 2, 2, 2, 3, 3, 3, 3. Joanne adds together the numbers on the 3 counters to get her total. What is the probability that he total is 6? Thank you.

    asked by Eleanor
  12. Chemistry

    A weather balloon is filled with helium that occupies a volume of 4.39 x 10^4 L at 0.995 atm and 32.0°C. After it is released, it rises to a location where the pressure is 0.720 atm and the temperature is -14.1°C. What is the volume of the balloon at

    asked by phillip
  13. Math

    In what proportion should you combine 2:5 soaking solution and distilled water to create 1:20 solution?

    asked by Brianna
  14. PHYSICS QUESTIONS

    Two springs, with force constants k1=175N/m and k2=270N/m, are connected in series, as shown in (Figure 1) .When a mass m=0.50kg is attached to the springs, what is the amount of stretch, x?

    asked by anonymos
  15. physics

    fluid of constant density = 960 kg/m3 is flowing steadily through the above tube. The radius at the sections are r1 = 0.05 m, r2 = 0.04 m. The gauge pressure at 1 is P1 = 200 000 Pa and the velocity here is v1 = 5 m/s. We want to know the gauge pressure at

    asked by Maha
  16. History

    1. "If slavery is not wrong, nothing is wrong ... And yet I have never understood that the Presidency conferred upon me an unrestricted right to act officially upon this judgment and feeling ... I claim not to have controlled events, but confess plainly

    asked by Parker
  17. Chemistry

    The enthalpy of combustion of benzoic acid (C6H5CO2H) is –3228 kJ/mol. The burning of 1.698 g of benzoic acid in a calorimeter causes the temperature to increase by 2.865 ºC. What is the heat capacity (in kJ/ºC) of the calorimeter?

    asked by Anon
  18. physics homework

    When a mass m=0.50kg is attached to the springs, what is the amount of stretch, x? When a mass m=0.50kg is attached to the springs, what is the amount of stretch, x?

    asked by ani
  19. Physics

    A 30 ohm resistor is connected in parallel with a variable resistance R and the parallel combination is then connected in series with a 5 ohm resistor, and connected across 120 volt source. Find the minimum value of R if the power taken by R is equal to

    asked by Mycah
  20. Physics - Voltage across a wire of unknown length

    Four copper wires of equal length L are connected to a 100V source. Their cross-sectional area are 1cm^2, 2cm^2, 3cm^2, and 4cm^2. Find the voltage across the 3cm^2 wire. Leave your answer in terms of L, it should cancel out. - So I tried using and

    asked by Kid
  21. Math

    Show that the bisector of the vertical angle of an isosceles triangle bisect the base at right angles

    asked by Sudarshan
  22. physics question

    When you take your 1700-kg car out for a spin, you go around a corner of radius 55 m with a speed of 20 m/s. The coefficient of static friction between the car and the road is 0.88.Assuming your car doesn't skid, what is the force exerted on it by static

    asked by anonymos
  23. commercial law

    Discuss the res perit domino rule in a contract of sale.

    asked by Anonymous
  24. Chemistry-Urgent

    A gas at 61°C occupies a volume of 0.67 L. At what Celsius temperature will the volume increase to 1.12 L? whats the answer didn't understand

    asked by Brianna
  25. English

    W:Hello. May I speak to Mr. Johnson? M: Speaking. 1. Who's calling, please? -------------------------- 2. Who's talking, please? 3. Who's speaking, please? (Can we use #2 and #3 instead of #1 in telephone conversation?)

    asked by rfvv
  26. PHYSICS

    When a 8.88 kg mass is placed on top of a vertical spring, the spring compresses 4.54 cm . Part A Find the force constant of the spring. 8.88kg*9.81=87.1128 divided by4.54 =19.187N/CM 0.0001918784141 KN/M IS IT RIGHT? PLS HELP

    asked by ani
  27. Chemistry

    A fixed amount of oxygen gas is held in a .500 L tank at a pressure of 4.09 atm. The tank is connected to an empty 1.50 L tank by a tube with a valve. After this valve has been opened and the oxygen is allowed to flow freely between the two tanks at a

    asked by robert
  28. Statistics

    LED light bulbs are manufactured with an average life span of 16 years and the bulb lifespans are known to follow an exponential distribution. a. What is the probability that a bulb will last longer than 14 years? b. What is the 50th percentile (or median)

    asked by Amanda
  29. Physics 2

    α of gold is 14.3x10^-6/C°. The density of gold is 19.3 g/cm^3 at 20℃. Determine its density at 140℃.

    asked by Alexa
  30. physics

    Driving in your car with a constant speed of v= 22 m/s, you encounter a bump in the road that has a circular cross-section, as indicated in the figure. If the radius of curvature of the bump is 52 m, find the apparent weight of a 66-kg person in your car

    asked by ani
  31. Maths

    A deposit mature to 24200 after 3yeras at simple interest of7 percent per annum what is the principal amount of deposit

    asked by Shary
  32. Macroeconimcs

    2. Suppose the national debt is $80 trillion and the government spends $800 billion during the fiscal year on goods and services. In addition, the government collects tax revenues of $600 billion and makes transfer payments equal to $300 billion. Assume

    asked by Tracy
  33. Geometry

    On the scale drawing of a floor, plan A room is 7 in. long on the scale drawing. Find the actual length of the room.

    asked by Maria
  34. Math

    The 6th and the 13th term of a GP are 24 and 3 by 16 respectively find the sequence

    asked by Usha
  35. Chemistry

    Air trapped in a cylinder fitted with a piston occupies 163.1 mL at 1.08 atm pressure. What is the new volume when the piston is depressed, increasing the pressure by 25%?

    asked by phillip
  36. Statistics

    The weight of a randomly selected shipping container follows an unknown distribution with mean 12 tons and standard deviation 2 tons. Your cargo ship always carries a load of 100 randomly selected shipping containers. a. What is the probability the load

    asked by Amanda
  37. Statistics

    The admissions counselors at rainy University believe that the freshman class they have just recruited is the brightest yet. If they want to test this belief (that the freshmen are brighter than the other classes), what are the null and alternative

    asked by Ann
  38. Maths

    The hcf of 140 and x is 20. The lowest common multiple of 140 and x is 20. What is the value of x? Thank you.

    asked by Eleanor
  39. Physics

    A ray of light with wavelength 589 nm passes through an unknown material with a velocity of 1.94 x 10^8 m/s. What is the material? I think this problem has something to do with Snell's law, but there is no given angle of refraction so I don't know how to

    asked by George
  40. Statistics

    Consider the population (1,3). Suppose you take all possible samples of size n=3 with replacement. What is the sampling distribution of the sample total?

    asked by Amanda
  41. Chemistry

    If the thermometer reads 22 c and this corresponds to 19.8mmhg of water pressure , what is the pressure of a pure gas collected over water if the total pressure is 760 mmhg?next calculate the pressure of the gas and lets assume its hydrogen gas in atm.

    asked by Flor
  42. Chemistry

    The pressure of a sample of helium in a 3.40 L container is 0.988 atm. What is the new pressure if the sample is placed in a 2.15 L container?

    asked by ciera
  43. rida

    50 meter cloth is purchased for rs 3725 how much cloth is purchased for rs 1788

    asked by sanam
  44. Science

    A car starts from a stopped position at a red light. At the end of 60 seconds, it's speed is 30 meters per second. What is the acceleration of the car?

    asked by Kallie
  45. Physics

    Ten cars at an intersection are blowing their horns simultaneously, creating a 100 decibel sound in the middle of the intersection. What is the average sound level for each car? 10/100= 10db per car?? Idk

    asked by Jared
  46. chem

    Air trapped in a cylinder fitted with a piston occupies 162.2 mL at 1.08 atm pressure. What is the new volume when the piston is depressed, increasing the pressure by 25%? what is the answer? didnt understand?

    asked by Brianna
  47. Algebra

    Helen deposited $1200 at 5% interest compounded continuously. After 6 years, how much did she have ? I got $2,160 but I was told it was incorrect

    asked by Marryy
  48. English

    Jaywalking is a minor_____ of the law. choices: transgress or transgression answer: transgression

    asked by Kimmy
  49. math

    Compound Interest formula solution P[1+r/100]t?

    asked by Subham
  50. physics

    the Ferris wheel has a diameter of 150m and takes 30min to make a full circle. Determine the speed of ride in m/s

    asked by tatenda
  51. Math fp1

    I have a general question For example we have matrix M1 and mattix M2, 2x2 both I wanna do the product m2m1m1m2m2m1m1m2 Is there a shortcut like factorising? Can you give me some basic rules about these please? Thank you

    asked by Stephan
  52. physics

    A water main with a radius of 0.15 m contains water with an average velocity of 3 m/s .What is the flow rate in the water main?

    asked by Maha
  53. algebra

    Find the lengths of each side of this triangle. Show calculations. Short arm=X; Long arm=1/2X+11; Hypotenuse=2X+1. Thanks a lot for your help.

    asked by Anneliese
  54. math

    the distance between two towns A and B is 150 kilometers. This distance is represented on a map by a length of 300 millimeters. If the scale of this map is in the form of 1:a, find the value of a

    asked by Anonymous
  55. Macroeconomics

    Suppose the national debt is $80 trillion and the government spends $800 billion during the fiscal year on goods and services. In addition, the government collects tax revenues of $600 billion and makes transfer payment equal to $300 billion. Assume the

    asked by Tracy
  56. Business Math

    split level for 200,000 put down 30% assuming rate of 11 1/2% on 30-year mortgage, determine monthly payment.

    asked by Ann
  57. english

    what verb tense is "having spent"

    asked by homework
  58. History

    Who was alvars and nayanars

    asked by Sudarshan
  59. maths

    evaluate 54 base 6+ 506base 6giving your answer in base 6

    asked by buhlalu sibonginkosi
  60. chem

    A gas at 61°C occupies a volume of 0.67 L. At what Celsius temperature will the volume increase to 1.12 L?

    asked by Brianna
  61. Mathematics

    X+6 _________ | \ | \ |x-1 \ | \ |____________\ 3x-4 The area of the trapezium is 119cm. What is the value of x? Thank you.

    asked by Joseph
  62. Mathematics

    X+6 _________ | \ | \ |x-1 \ | \ |_____________\ 3x-4 The area of the trapezium is 119cm. What is the value of x? Thank you.

    asked by Joseph
  63. Math

    How to get 44 using the digits in 2017. You can use +,-,×,÷,√,!,!!,exponents. Double digit numbers are allowed

    asked by Help
  64. chem 111

    state fist ionization energy of calcium high than pottatium

    asked by Anonymous
  65. math

    In one minute, Sasha takes 43 steps. It takes her 301 steps to travel from her house to the shops. If she leaves home at 10:24,at what time will he reach the shops if he walks steadily?

    asked by sara