Questions Asked on
July 20, 2016

  1. Chemistry

    For two questions below, first write and balance the equation for the chemical reaction.  Please, also review the material in Chapter 8, if you will feel you might need it in order to answer the questions.  Next, please answer the following questions:

    asked by Chem&Society
  2. Physics

    In each cycle of its operation, a heat engine expels 2400 J of energy and performs 1800 J of mechanical work. (a) How much thermal energy must be added to the engine in each cycle? (b) Find the thermal efficiency of the engine.

    asked by Theaaaa03
  3. Chemistry

    The atmosphere contains about 5.2 x1015 t of air.  What mass in metric tons of carbon dioxide is in the atmosphere if the concentration of CO2 is 395 ppm?

    asked by Chem&Society
  4. Chemistry

    Express each aqueous concentration in the unit indicated. 45 ppm NO3 -, as molarity of nitrate ion in [mol NO3 - /L].

    asked by Chem&Society
  5. Physics

    Two lead spheres at the same temperature have radii in the ratio 1:2.what is the ratio of their heat capacities

    asked by Vaishnavi
  6. Physics

    Your ear is capable of differentiating sounds that arrive at the ear just 1.00 ms apart. What is the minimum distance between two speakers that produce sounds that arrive at noticeably different times on a day when the speed of sound is 340 m/s?

    asked by Elizabeth
  7. Chemistry

    How many grams of hydrogen peroxide (H2O2) must be added to 1,500 ml of water to produce a concentration of 1.33 m (molal solution)?

    asked by Damon
  8. Chemistry

    The human body obtains 885 kJ of energy from a chocolate chip cookie. If this energy were used to vaporize at 100 degree Celsius, how many grams of water could be vaporized? The heat of vaporization of water at 100 degrees Celsius is 40.7 kJ/mole.

    asked by Jane
  9. Math

    A number sentence is 50 1/2 ÷1/4 =202. Part A. Create a story or context for this number sentence. Part B. Rewrite this number sentence using multiplication. Part C. Give a verbal explanation that describes how these three numbers are related.

    asked by Anonymous
  10. Calc

    the productivity of a person at work is modeled by a cosine function: 5cos (pie/2 (t)) +5, where t is in hours. If the person starts work at t=0, being 8:00 am, at what times is the worker the least productive?

    asked by Anonymous
  11. Chemistry

    For the system, H2(g) + X2(g) 2HX(g), Kc = 24.4 at 300 K. A system was charged with 2.00 moles of HX in a 3.00 liter container. The catalyst was introduced using a remote unit, and the system was allowed to come to equilibrium. How many moles of H2(g) will

    asked by Val
  12. Math

    Clark has 7 1/2 feet of wire. Part A. How many 3/4 foot pieces can Clark cut from the 7 1/2 feet of wire? Part B. Using the information in Part A, interpret the meaning of the quotient in terms of the two fractions given.

    asked by Anonymous
  13. chemistry

    Assuming all gases are at the same temperature and pressure, how many milliliters of hydrogen gas must react to give 41.0 mL of NH3? 3H2(g)+N2(g)→2NH3(g)

    asked by Maria
  14. math

    The angles of elevation of a balloon directly above a straight road, from two points of the ground on opposite sides of the balloon, are 78¡ã15' and 59¡ã47'. If the points are 5000ft apart, what is the height of the balloon?

    asked by james
  15. Chemistry

    For the teaction system, 2SO2(g) + O2(g) 2SO3(g), Kc has a value of 4.62 at 450.0K. A system, at equilibrium, has the following concentrations: [SO3] = 0.254 M, [O2] = .00855 M. What is the equilibrium concentration of SO2(g)? The correct answer is 1.28M,

    asked by Mikey
  16. Microsoft excell

    A rectangular range of cells with headings to describe the cells' contents is referred to as a A. table. B. complex formula. C. bar chart. D. sparkline. My answer is a.

    asked by Daniela
  17. Physics

    Two resistors of 2.0 ohm and 3.0 ohm are connected a) in series b) in parallel, with a battery of 6.0V and negligible internal resistance. For each case draw a circuit diagram and calculate the current through the battery

    asked by Bella
  18. Algebra

    A certain recipe requires 2 3/5 cups of flour, and 3 1/4 cups of sugar. a) if 3/8 of the recipe is to be made how much sugar is needed? b) if the above ingredients are required for one batch, find the amount of flour needed for a triple batch.

    asked by Christine C
  19. Math

    A mortgage of 200 000 is required to purchase a house. The mortgage will be repaid with equal monthly payments over 25 years at 10% compounded monthly. what is the monthly payment

    asked by Jennfier kosner
  20. statistics

    find the number of units that must be produced to break even. R(x)=200x - x^2 C(x)= 70x +2200 0 < x < 100 (These < are supposed to b less than or equal to signs)

    asked by Anonymous
  21. Math

    What is the pH of buffer solution prepared with 0.05 M ammonia & 0.05 M ammonium chloride? The Kb value of ammonia is 1.80 ✖️ 10^-5 at 25C.

    asked by Neth
  22. geography

    examine the sphere of influence of an organisation that renders a service in your are. e.g. clinic, hospital, a local high school?

    asked by josephinah
  23. Physics

    A second's pendulum is taken on the surface of moon where acceleration due to gravity is 1/6th of that of earth.Will the time period of pendulum remain same or increase or decrease?Give a reason.

    asked by Yashasvi
  24. science

    When a body hanging form a spring balance is immersed in water it floats just below the surface of water and shows 100 g loss in its water ? (1) what is the weight of the body in water? (2) what is the weight of the body in air? (3) what is the upthrust on

    asked by parag
  25. GPH 111

    On a map with a scale of 1:12,000, a measured distance of 1 inch represents what distance in feet? With work

    asked by Bethany
  26. mathematics

    what is the probability that today is tuesday and tomorrow is wednesday

    asked by Anonymous
  27. Math - Trig

    The equation given below models the average monthly temperature (˚C). t denotes the number of months with t=1 representing January. During which months is the average monthly temperature 12.5˚C? 𝑇(𝑡) = 12.5 + 15.8sin (𝜋/6 (𝑡) −2𝜋/3)

    asked by Anonymous
  28. Physics

    ABC is an equilateral triangle of side 4.0 cm in a vacuum. There are point charges of 8.0C at A and B. Find (a) the potential, (b) the electric field at C.

    asked by Hezekiah
  29. Math

    Part b using the information in part a , interpret the meaning of the quotient in terms of the two fractions given

    asked by Angela
  30. Math

    There are 45 students in a class of which 3/5of them are boys.how many girls ate there in the class?

    asked by Nad
  31. Math

    The dimensions of a rectangular prism are Length 2/14 feet width 1 foot Height 1 1/4 feet. The length of the sides of a small cube are 1/4 foot each. Part A. How many small cubes can be packed in the rectangular prism? Part B. Use the answer obtained in

    asked by Anonymous
  32. math

    the product of three numbers is 315.if two of the numbers are 7 and 9 .what is the third number?

    asked by joshua
  33. math

    Given that 0 ≤ 𝑥 ≤ 𝜋/2and 0 ≤ 𝑦 ≤𝜋/2 find the exact value of 𝑡𝑎𝑛(𝑥 + 𝑦) if 𝑐𝑜𝑡(𝑥) =6/5 and 𝑠𝑒𝑐(𝑦) =3/2

    asked by Stacy
  34. Calc

    a large closed storage rectangular box with a base constructed with two different types of wood. the base is made up of wood $5 per square feet and the top and sides are made of wood $3 per square feet suppose the amount available to spend is $1000 find

    asked by James
  35. Math

    In a group of 500 students, 150 are studying physics, 220 are studying biology, and 100 are studying chemistry. At least 25 students are studying more than one of these sciences. What is the greatest possible number of these students that might NOT be

    asked by Anonymous
  36. valuemath

    muli's farm had sheep and goats in the ratio 3:4 respectively, cows and goats in the ratio respectively.if he had 20 goats,how many animals did he have altogether?

    asked by valueEric
  37. chemistry

    The compete oxidation of 2g of an aldehyde A by acidified potassium chromate produces 2.1g of carboxylic acid B which is dissolved in 50 ml of distilled water . The obtained solution reacts with exactly 1.05 g of solid lime to form salt C a) Write the

    asked by dani
  38. Math

    How many small cubes can be packed in the rectangular prism

    asked by Karuun
  39. Math

    if sec(x) = - squaroot 20 /3 (squroot applies to 20 not the fraction) then state the exact vale of tan (x)

    asked by Anonymous
  40. physics

    An infinitely-long wire with resistivity 2.0*10^-8 ohm*m initially has 1.5 A of "conduction" current flowing through it. When the emf connected to the wire is turned off, this current stops in time of .6ns. Estimate the amount of displacement current

    asked by Sally
  41. physics

    Solar material has a density of about 3*10^-4kg/m^3,and the amount of matter released in a typical CME is around 1*10^15kg. Assuming mu solar material is mu_0, estimate the strength of the magnetic field at the suns surface during typical CME

    asked by unknown
  42. math

    the sum of three consecutive numbers is eighteen. Write an expression describing the equation and solve the state of the three numbers

    asked by Erica
  43. Math

    For what value(s) of r is r^2+5r+6/r+2 equal to 0? A) -2 only B) -3 only C) 3 only D)-2 or -3 E) 2 or 3 I got A but it is incorrect and I'm still confused Thanks

    asked by Damon
  44. English

    What is the simple subject of the following sentence? Several sites on the internet give information about extreme sports. I believe the simple subject is: sites

    asked by Blake
  45. Math - Trig

    A hamster enters a wheel at the lowest point and begins to run . The height of point R (in the diagram below) above the ground is given by the function ℎ(𝑡) = −17.5 cos ( 2pi/3 𝑡) + 19, where ℎ is height in centimeters and 𝑡 is time in

    asked by Anonymous
  46. Physics

    The answer "use the right-hand rule" isn't working for my brain. I'd really like to understand how to answer the following: You can make an electromagnet by wrapping wire around a wire and connecting the ends to a battery. If the battery is connected so

    asked by Anna
  47. college physics

    Suppose an aeroplane is moving in the north direction and magnetic field is into the paper .Which part of aeroplane will b positively charged? A-its head B-its left wing C-its tail D- its right wing

    asked by Ghulam
  48. math

    show that abc is a right angled isosceles triangle prove that AD>AC and AC>CD also arrange in ascending order

    asked by dcs
  49. math

    The area of a variable rectangle is increasing at the rate of 40cm/s. The length of a rectangle is always equal ti the square of the breadth. At what rate the length is increasing at the instant when the breadth is 8cm?

    asked by bengia lucy
  50. maths

    a cyclist cycles for 2h at a speed of 27km/h. he then cycles for 11/2h at an average speed of 20km/have. fin the average speed for the whole journey.

    asked by manasi rycha
  51. math

    the sum of three consecutive numbers is eighteen. Write an expression describing the equation and solve the state of the three numbers

    asked by Erica
  52. physics

    what is pin hole cemera

    asked by musa ezekiel
  53. maths

    A rectangular garden is to be constructed using 100 metres of fencing but using a straight wall as one side.the rectangle is x metres. Find the lenght of the garden in terms if x?

    asked by Bryan
  54. Algebra

    C the power of two+18c-175=0 Help please?

    asked by Ben
  55. Math

    The tornadoes have won 75% of their games. If they their next 4 games, their win percentage goes up to 80%. How many games have they played right now? (Please explain how to solve this problem)

    asked by Selina
  56. Math

    If given the graph of 𝑓(𝑥) = − sin (3x + 𝜋/3 ) − 2 describe the steps you would take to draw the graph of the reciprocal function

    asked by Anonymous
  57. Math

    On each of four cards, a different positive integer greater than 1 but less than 20 is written. Exactly 3 of the numbers are multiples of 3, exactly two of the numbers are multiples of 5, and none of the numbers is even. What is the sum of these four

    asked by Lenin
  58. Math

    At a certain store, employees may buy clothing at a 20% discount from the original price, but must pay a 6% sales tax. If the final cost of a sweater purchased by an employee is $55.12 what is the original price of the sweater, before the discount and tax?

    asked by Anonymous
  59. Chemistry

    How many liters of HCl acid needed to dissolve at 1 ton of carbon and how long would it take?

    asked by Derrick
  60. Physics

    A paper ball is dropped from a height of 5 meters above the ground. It hits the ground traveling with a speed of 2 m/s. How much work did air resistance do on the paper ball? I don't know how to start this. PLease help

    asked by Jay
  61. physics

    a car moving through road what is the direction of force and surface of acting

    asked by Anonymous
  62. physical science

    which sibstance has the least number of drops that can fit on the coin?

    asked by ikhandlela
  63. science

    According to chance what fraction of their children will have dimples?

    asked by Haziq Mehboob
  64. Math

    Roots. Solve and check 1/4 -1/x+6= 1/x

    asked by Cazi melar
  65. SCIENCE

    WHAT CAN BE THE ARRANGEMENTS OF PARTICLES IN MERCURY

    asked by SHAFAQ
  66. Math

    How far will a 4ft diameter wheel travel while making 100 revolution?

    asked by Paul
  67. math

    if the ratio of interior angle of triangle are 4:11:3.Find the greater angle.* i am confused about the word greater does the question need the angle with 11 ratio or 4 ratio?

    asked by kelvin
  68. physics

    A particle is moving along a circular path of radius r, when it makes half a rotation, what is the ratio between its displacement and distance? (a) 2π (b) π (c) π/2 (d) π/4

    asked by SAGAR
  69. math

    ther 840 people in mrs mitchells class and 453 people in mrs coles class i want to know how many people all are toghether

    asked by melshia griffin
  70. statistics

    What is straight line depreciation for an item that costs $15,951. whose life is 13 years?

    asked by Anonymous
  71. Geometry

    Describe the translation. y=(x−5)2+5 → y=(x−0)2+0

    asked by BigCherry123
  72. Geometry

    Describe the translation. y=(x−5)2+5 → y=(x−0)2+0

    asked by BigCherry123