Questions and answers by visitors named sarah


  1. A child is standing on a platform of a station.

    A train travelling at 30m/s takes 3.0 secs to pass the child.What is the length of the train. a)10m-this was my answer b)27m c)30m d)90m

  2. Shawn and his bike have a total mass of

    51.1 kg. Shawn rides his bike 1.7 km in 10.7 min at a constant velocity. The acceleration of gravity is 9.8 m/s squared. What is Shawn’s kinetic energy? Answer in units of J.

  3. A tuning fork is set into vibration above a vertical open tube filled with water. The water level is allowed to drop slowly. As it does so, the air in the tube above the water level is heard to resonate with the tuning fork when the distance from the tube

  4. Raymond buys bottles of water at $2.10 each and a large pizza at $12.99. The total cost was $21.39. How many bottles of water b did he buy? Write an equation using the variable b use spaces before and after each math symbol.

  5. The lengths QR, RP, and PQ in triangle PQR are often denoted p, q, and r, respectively.

    What do the formulas 1/2 pq sinR and 1/2 qr sin P mean? After you justify the equation 1/2 pq sinR = 1/2 qr sin P, simplify it to a familiar form.

  6. Four darts are thrown at this dartboard. If all four darts hit the board, how many different point totals are possible?

    there are 4 circles with point totals: working out from the middle bulls eye.. bulls eye = 9 2nd circle = 7 3rd circle = 4 outter circle

  7. Assuming a temperature of 37 C and 1 atm pressure, how many mol/min of CO2 is this?

  8. seven horses are entered in a race. If two horses are tied for first​ place, and there are no ties among the other five ​horses, in how many ways can the seven horses cross the finish​ line?

  9. a drunken motorist who is moving at a constant velocity of 90 km/h passes a stationary police patrol car. The patrol car immediately gives chase at a constant acceleration and catches up with the motorist after a distance of 10 km. Calculate the time taken

  10. For a family with 2 children, the sample space indicating boy (B) or girl (G) is BB, BG, GB, and GG. If each of the outcomes is equally likely, find the probability that the family has 2 girls, given that the first child is a girl.

  11. On Team B 80% of the football players weigh more than 200 pounds. If 41 men are on the team, how many weigh more than 200 pounds?

  12. three forces with magnitudes 100, 50, and 80 lb act on an object at angles of 50 degree, 160 degree, and -20 degree respectively. ind the direction and magnitude o the resultant force.

  13. Two bulbs are connected in parallel across a source of emf EMF = 10.0V with a negligible internal resistance. One bulb has a resistance of 3.0 Omega , and the other is 2.5 Omega . A resistor R is connected in the circuit in series with the two bulbs. What

  14. 1)when a certain polynomial is divided by x - 3, the quotient is x^2+2x-5 and the remainder is -3. what is the polynomial

    2) Find each quotient and remainder. Assume the divisor is not equal to zero. a)(2x^2+29x-x^3-40)/(-3+x) b)(6+7x-11x^2-2x^3)/(x+9)

  15. An isosceles triangle has two 10.0-inch sides and a 2w-inch side. Find the radius of the inscribed circle of this triangle, in the cases w = 5.00, w = 6.00, and w = 8.00.

    Then Write an expression for the inscribed radius r in terms of the variable w , then

  16. find the number of integers between 32 and 395 that are divisible by 6

    find their sum

  17. Which statement correctly describes how hydrolysis causes chemical weathering?

  18. Which is the difference between a renewable resource and a nonrenewable resource?

    A. A renewable resource cannot be replaced for many lifetimes, and a nonrenewable resource can be replaced in the near future. B. A renewable resource is something that can be

  19. Belinda wants to invest $1000. The table below shows the value of her investment under two different options for three different years:

    Number of years 1 2 3 Option 1 (amount in dollars) 1100 1210 1331 Option 2 (amount in dollars) 1100 1200 1300 Part A:

  20. Given the function f(x) = 2(3)^x, Section A is from x = 0 to x = 1 and Section B is from x = 2 to x = 3.

    Part A: Find the average rate of change of each section. Part B: How many times greater is the average rate of change of Section B than Section A?

  21. The track team plans to sprint 20 miles this school year. The runners will sprint 1/4 mile each day.How many days will it take them to sprint 20 miles?

  22. A storage tank has a radius of x + 5 metres and a height of x metres. Determine the dimensions of the tank if the volume is 192ð m3? . Round your answers to two decimal places.

  23. an ice cube that is 8 cm on each side is melting at a rate of 4 cm^3 per min. how fast is the length of the side decreasing?

  24. Assume that 2 cards are drawn in succession and without replacement from a standard deck of 52 cards. Find the probability that the following occurs: the second card is a 9, given that the first card was a 9.

  25. A voltaic cell consists of a strip of cadmium metal in a solution of Cd(NO3)2 in one beaker, and in the other beaker a platinum electrode is immersed in a NaCl solution, with Cl2 gas bubbled around the electrode. A salt bridge connects the two beakers.


  26. A circular loop of flexible iron wire has an initial circumference of 168cm , but its circumference is decreasing at a constant rate of 15.0cm/s due to a tangential pull on the wire. The loop is in a constant uniform magnetic field of magnitude 1.00T ,

  27. How has climate change impacted the biodiversity around coral reefs?

  28. the speed of the fastest pitched baseball was 45 m/s, and the ball's mass was 145 g. (a) What was the magnitude of the momentum of this ball, and how many joules of kinetic energy did it have? (b) How fast would a 57 gram ball have to travel to have the

  29. Which best describes Francis Bacon’s contribution to the Scientific Revolution?

  30. Thomas is thinking of a number, if he doubles his number and subtracts 27, he gets 407. Whats his number?

  31. Austin is creating a new trail mix by 

    combining two of his best­selling blends. A pineapple­coconut­macadamia (pcm) mix that sells for $18/kg and a banana­papayapeanut (bpp) mix that sells for $10/kg. Write the equations and find the point of

  32. One kind of battery used in watches contains mercury(II) oxide. As current flows, the mercury(II) oxide is reduced to mercury.

    HgO(s) + H2O( ) + 2 e–  Hg( ) + 2 OH–(aq) If 2.3  10–5 amperes flows continuously for 1200 days, what mass of Hg( ) is

  33. Can one calculate the number of moles of air? If so, calculate the number of moles in 1 kg of air (making sure your calculation, units and assumptions are fully explained); If not, explain why it is not possible to calculate the number of moles of air.

  34. How many grams of TiCl4 are needed to produce 17.8 g of titanium? what equation do i use?

  35. If the equilibrium constant for a one-electron redox reaction at 298 K is 7.8 104, calculate the corresponding ÄG° and E°cell.

    how would i set this problem up?

  36. A statistician wants to estimate the mean weekly family expenditure on clothes. He believes that the standard deviation of the weekly expenditure is $125. Determine with 99% confidence the number of families that must be sampled to estimate the mean weekly

  37. the pH of a solution of HIO3 (Ka=1.7x10^-1) and KIO3 is 1.00. what is the molarity of KIO3 if the molarity of HIO3 is 0.025 M?

  38. consider the following statement: if a circle with its center at the origin has a chord with slope m, the equation of the right bisector of the chord is y=mx. Is this statement true or false? explain

  39. a 1.0kg ball is thrown upward from 1.0m above the ground with a speed of 10m/s reaches a height of 4.5 m. what is the efficiency of the energy transformation?

  40. i was wondering if i did this right

    A cannon ball is shot from a cannon on top of a hill that is 73.5 meters above sea level. The cannon ball leaves the cannon with a velocity of 9.8 m/s. Write and solve a quadratic equation to determine when the cannon

  41. A tennis ball is launched with an initial velocity of 24.5 m/s from the edge of a cliff that is 117.6 meters above the ground. Which quadratic equation could be used to correctly determine when the ball will hit the ground

  42. Find the horizontal distance the skier travels before coming to rest if the incline also has a coefficient of kinetic friction equal to 0.23. (The incline makes an angle θ = 20.0° with the horizontal.)

  43. Calculate the molarity and mole fraction of acetone in a 1.29 m solution of acetone (CH3COCH3) in ethanol (C2H5OH). (Density of acetone = 0.788 g/cm3; density of ethanol = 0.789 g/cm3.) Assume that the volumes of acetone and ethanol add.

  44. 21 is three times the difference between 4 times a number and 5.

  45. a metal tank with a volume of 3.10 L will burst if the absolute pressure of the gas exceeds 100 atm. If 11 mol of an ideal gas is put into the tank at a temperature of 23.0 C, to what temperature can the gas be warmed before the tank ruptures? Neglect the

  46. can you unscramble this word using these letters : abdhimnry? It is supposed to be an animal.

  47. (10 Squar root -13)(-5 square root -5)

    put in standard form a+bi I really don't understand square roots so can you show me how to do these please

  48. Does the KE of a car change more when it goes from 10 to 20 km/h or when it goes from 20 to 30 km/h?

  49. a large bedsheet is held verticallyy by two students. A third student who happens to be the star pitcher on the baseball team, throws a raw egg at the sheet. explain why the egg doesn't break when it hits the sheet, regardless of its initial speed.

  50. let f be function given by f(x)= Ln(x)/x for all x> 0. the dervative of f is given by f'(x)= (1 - Ln(x))/x squared.

    a) write equation for the line tangent to the graph of f at x=e squared b) Find the x-coordinate of the critical point of f. Determine wheter

  51. If N2 is added to a balloon that contains O2 (partial pressure 460 mm Hg) and CO2 (partial pressure 110 mm Hg) to give a total pressure of 830 mm Hg, what is the partial pressure of each gas in the final mixture?

  52. It is important that muscle cells in the heart are able to coordinate their contractions so that all the cells in a given region of the heart contract at the same time to efficiently expel the blood from the chamber. Which of the following possible

  53. how much sample needs to be placed in the capillary tube to determine a melting point?

  54. careless praparation of a smple is leading cause of inaccurate and irreproducible results in melting point determinations.any subtance being loaded into melting point capillary must be:

  55. 4 over 5 plus 8 over 9

  56. What is the definition of epistasis?

  57. an immersion electric heater used in the lab will increase the temperature of 500 ml of water by 50 degree in 6 min when operated with 120v supply?what power does the heater deliver ?b what current does it draw?

  58. The senior classes at Spanish River and Atlantic planned separate trips to Universal Studios. The senior class at

    Spanish River rented and filled 1 van and 6 buses with 372 students. Atlantic rented and filled 4 vans and 12 buses with 780 students. Each van

  59. Given that x varies directly as the square of y and x=2 when y=1, Find x when y=4

  60. Winds, air pressure, evaporation, and the angle of the sun shape the daily

    Choose... of each place.

  61. why is art created

  62. A theater earns $3640 from a concert. An orchestra ticket costs three times as much as a balcony ticket. Write a system of linear equations that represents this situation. What is the price of each type of ticket?

  63. what is the smallest of the three consecutive numbers when squared add up to 365?

  64. what is the smallest of three consecutive numbers when squared add up to 365

  65. a school has a total enrolment of 90 students. there are 30 students taking physics, 25 taking english and 13 taking both. what percentage of the students is either taking physics or english?

  66. Is white blood cell count of 18,000 cells/L low or high? If yes, what is the normal WBC in cells/L?

  67. the periodic table is arranged by various patterns. is there a pattern with regard to ionic charge? In three to five sentences, explain your reasoning and provide specific examples

  68. The sum of 21 and Greg's score is 57

    Use the variable g to represent Greg's score.

  69. If you roll a 6-sided die 66 times, what is the best prediction possible for the number of times you will roll an even number?

  70. find the exact circumference of the circle 6 radius 2

  71. four less than the product of some number and 6

  72. 1. A stopwatch starts while race car travels at 7 m/s from the pit area and accelerates at a uniform rate to a speed of 30 m/s in 19 s moving on a circular track of radius 511 m.

    Assuming constant tangential acceleration, find (a) the tangential

  73. 1.25 +

    410 410 −35 −35

  74. if the diameter of a cookie is 12 what is the area

  75. What effect did the American Revolution have on the French Revolution?

  76. Sarah can type 1800 words in 40 minutes. How many words can she type in 30 minutes?

  77. The fuel tank in Alisha’s car holds

    16.5 gallons, and the car gets 24miles per gallon for city driving and 30miles per gallon for highway driving. Which inequality represents the range of the total number of miles, m, Alisha can drive on a tank of gas?

  78. A rectangular dog pen is constructed using a barn wall as one side and 50 meters of fencing for the other three sides. What is the maximum area of the dog pen?

  79. asale earn a basic salary of 9000 per month in addition he is paid a commissin of 5%for sales above 15000 in acertain month he sold good worth 12000at a discount of two and ahalf calculate his otal earning

  80. 2HBr(g) + Cl2(g)2HCl(g) + Br2(g)

    ΔH° = -81.1 kJ and ΔS° = -1.2 J/K The maximum amount of work that could be done when 2.05 moles of HBr(g) react at 274 K, 1 atm is...?

  81. A project is expected to be completed in 16 days. The variance of the project duration is 3 days.

    (8 points) a. What is the probability that it will be completed in 18 days? b. What is the probability that it will take more than 19 days to finish? c. What

  82. what is 54 times 154

  83. What are the advantages and disadvantage of using a ramp?

  84. Which organ systems work together to support nutrients and oxygen to the brain? *

  85. A class consists of 45 students. Ten of these students received an "A" for the final exam. Five students are selected at random from this group.

    a) What is the probability that three of the five students selected received an "A" for the final exam? b) What

  86. The number of traffic accidents per day on a certain section of highway in the past was 4 accidents per day in average. Based on this,

    a) What is the probability that there may be exactly two traffic accidents tomorrow? b) What is the probability that there

  87. Relative humidity is a measure, expressed as a percentage, of the amount of water vapor present in air. The following histogram summarizes the relative humidity, at noon, for a random sample of 100 days for a certain city. Based on the histogram, which of

  88. i need help with operations with fractions lesson 12 unit 4


  89. by studying the bones and teeth of the mastodon remains found on the manis farm, what where the scientists able to prove?

    I NEED HELP!!!

  90. what statement best says how London develops White Fang’s character in the excerpt?

  91. Which of the following statements about Aborigines is false?

    A. They were nomadic hunter-gatherers. B. They lived in small groups called clans. C. They used spears, nets, and boomerangs to hunt. D. They spoke one common language and had shared religious

  92. A Christmas tree ornament resembles a spherical convex mirror and is 5.6 cm in diameter. What is its focal length (in cm)?

  93. Check 0/4 pts Retries 2

    A bag contains 2 gold marbles, 7 silver marbles, and 26 black marbles. Someone offers to play this game: You randomly select one marble from the bag. If it is gold, you win $4. If it is silver, you win $2. If it is black, you lose $1

  94. How many neutrons does the most common isotope of carbon contain? Use the diagram below to help you.

  95. Which of these values was central to the Transcendentalist writers?

  96. What is the equation of a circle with its center at (10,−4) and a radius of 2?

    (x−10)2+(y+4)2=4 (x+10)2+(y−4)2=2 (x−10)2+(y+4)2=2 (x+10)2+(y−4)2=4 can someone please help i do not understand

  97. Why are rising sea levels a concern in Australia and New Zealand?

    A. High tides and storm surges may damage property in coastal areas. B. Australia and New Zealand may disappear completely if sea levels continue to rise. C. Rising sea levels are changing

  98. Ben and Maddie both use triangles to determine the slope of the line.Ben determines the slope of line l to be -2. Maddie says the slope of line is 1/2.Who is correct?

  99. i'm not very good at math whats an easy way to learn rise over run and slope, i'm an 8th grader i really need help.

  100. olivia can complete 6 sprints per minute.write and solve a direct variation eqation to find how many sprints she can expect to complete in 25 minutes. i really need the answer


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