# SAM

Most popular questions and responses by SAM
1. ## Physics

While working on her bike, Amanita turns it upside down and gives the front wheel a counterclockwise spin. It spins at approximately constant speed for a few seconds. During this portion of the motion, she records the x and y positions and velocities, as

29. ## geometry

Martin drew a pair of perpendicular lines and a pair of parallel lines. Which of these statements best compares the pairs of perpendicular and parallel lines? Answer A: Perpendicular and parallel lines always have a common endpoint. B: Perpendicular and

30. ## algebra

The loudness, L L, of a sound (measured in decibels, dB) is inversely proportional to the square of the distance, d d, from the source of the sound. Round to 3 decimal places. A person 15 feet from a jetski, it is 75 decibels loud. How loud is the jetski

31. ## Math

A shop owner blends three types of coffee,A,B,C.in the ratio 3:5:7 a) calculate the weight of each type of coffee in 45kg of three blended mixture. b) given that type A coffee cost $7 per kg, type B coffee costs$10 kg and type C coffee costs \$13 per kg,

32. ## Algebra 1

A square painting is surrounded by a frame. the outside edges of the frame are x inches in length, and the frame is 3 inches thick. What is the total area of the frame? A)-12x+36 B)12x-36 C)x^2+12x+36 D)x^2-12x-36 Is it C or D?

33. ## History

which of the following was a significant part of the civil rights movement? a.) the civil rights movement got national attention. b.) laws were passed as a result of the civil rights movement. c.) the president provided support of the civil rights

34. ## Chemistry

Iron (III) Nitrate reacts with Sodium Carbonate to form a precipitate. Be sure to indicate oxidation states (charges on each ion) & the precipitate. Skeletal Equation: Ionic Equation: (assume all ions are aqueous, dissociated free ions) NET Ionic Equation:

35. ## Chemistry

A 5.0-g Sample of KBr at 25.0 degrees celsius dissolves 25.0 mL of water also at 25.0 degrees celsius. The final equilibrium temperature of the resulting soltution is 18.1 degrees celsius. What is the enthalpy of of solution in kilojoules per mole of KBr?

36. ## math

Is this the right way to answer this question? A physics exam consists of 9 multiple-choice questions and 6 open-ended problems in which all work must be shown. If an examinee must answer 7 of the multiple-choice questions and 3 of the open-ended problems,

37. ## Literature

Jack London never actually set foot north of California a. true b. false *****

38. ## math

A study was made of 200 preschoolers to determine if they watched some particular television shows. The choices were Little Galileo, Super Reader and Prehistoric Train. The results are I. 22 preschoolers did not watch any of these shows II. 73 preschoolers

39. ## math

What Happens to People Who don't Know Toothpaste From Putty?

40. ## physics

A helicopter weighs 3920 newtons, caculated the force on it if it is ascending up at a rate of 2m/s squre ,what wil b force on helicopter if it is moving up with the constant speed of 4m/s .

41. ## science

A particle beam is made up of many protons each with a kinetic energy of 3.25times 10-15J. A proton has a mass of 1.673times 10-27kg and a charge of +1.602times 10-19C. What is the magnitude of a uniform electric field that will stop these protons in a

42. ## Physics

An automobile with 0.310 m radius tires travels 85,000 km before wearing them out. How many revolutions do the tires make, neglecting any backing up and any change in radius due to wear?

43. ## Physics

how much energy is required to change 40 g of ice at -10 C to steam at 110 C?

44. ## science

if the specifc heat of iron = 0.46J/g C,how much heat is needed to warm 50g of iron from 20C to 100C -- I do not know how to make the celcius o above the temperature number my anwswer Q = Mx(delta)TxC Q=50gx80Cx0.46J/gC Q = 1840 Joules Delta = the triangle

45. ## Social Studies Help ASAP Please!

Resistance to Immigration Nativists believed that some immigrants did not fit into American culture because their customs were to different ---> Prejudice and violence grew as the number of Chinese immigrants increased ---> ? Based on your reading, which

1. Population density is the number of people that live in a region divided by the number of (1 point) roads. square miles or kilometers in the region.•• waterways. people who used to live there. 2. How do demographers figure out population growth? (1

47. ## Chemistry

Complete the charge balance equation for an aqueous solution of H2CO3 that ionizes to HCO3^- and CO3^2- ______ = ______ + _______ + _______ Given choices: [HCO3^-],[CO3^2-], [OH^-], 2[H^+], [H2CO3], 2[CO3^2-], 3[H^+], {H^+] I don't understand how to do

48. ## math

Mark averaged 60 miles per hour during the 30-mile trip to college. Because of heavy traffic he was able to average only 40 miles per hour during the return trip. What was Mark's average speed for the round trip?

49. ## Physics

A dentist's drill starts from rest. After 3.20 s of constant angular acceleration it turns at a rate of 2.7 104 rev/min. (a) Find the drill's angular acceleration. (b) Determine the angle (in radians) through which the drill rotates during this period.

50. ## calculus

A box weighing 450 N is hanging from two chains attached to an overhead beam at angles of 70 degrees and 78 degrees to the horizontal. Determine the tensions in the chains.

51. ## Physics

to strengthen his arm and chest muscles, an 82-kg athlete who is 2.0 m tall is doing push ups. his center of mass is 1.15 m from the bottom of his feet, and the centers of his palms are 30.0cm from the top of his head. find the force that the floor exerts

52. ## Physics II

A test charge of +2 μC is placed halfway between a charge of +6 μC and another of +4 μC separated by 10 cm. What is the magnitude of the force on the test charge?

53. ## art

in near eastern culture the winged genius often represented in art and artifacts was a blank god a.destructive b.creative c.understanding d.benevolent

54. ## math/ratios

There are 77 students in the student council. The ratio of girls to boys is 7:4. How many girls are in the student council?

55. ## Analytical Chemistry

Carbon dioxide dissolves in water to form carbonic acid, which is primarily dissolved CO2. Dissolved CO2 satisfies the equilibrium equation. CO2(g) CO2(aq) The acid dissociation constants listed in most standard reference texts for carbonic acid actually

56. ## Chemistry

List the following compounds in order of increasing electrical conductivity: 0.1 M formic acid (HCOOH), 0.1 M (NH4)3PO4, 0.1 KCl, and 0.1 M glucose solution (C6H12O6). Why are they in that order?

57. ## math

The area of a trapezoid may be determined by using the formula A = (h/2)(a+b), where "A" stands for area, "h" stands for the height of the trapezoid, and "a" and "b" stand for the lengths of the bases of the trapezoid. If the height of the trapezoid is12

58. ## Maths

We have Rs.100/-.If we spend Rs.100/-and balance is Rs.102/-,show how is Rs.2/-extra Spent Balance Day 1 Rs 40 Rs 60 Day 2 Rs 30 Rs 30 Day 3 Rs 18 Rs 12 Day 4 Rs 12 Rs 00 -------- -------- Total Rs 100 Rs102......?

59. ## Math

Two cards are selected at random without replacement from a well-shuffled deck of 52 playing cards. Find the probability of the given event. A pair is not drawn.

60. ## Science

Which Of the following differs when comparing the deep ocean to the intertidal zone?? A) Need for Energy B) Salinity C) The amount of sunlight* D) Reliance on phytoplankton

61. ## math

One pipe fills a storage pool in 20 hours. A second pipe fills the same pool in 15 hours. when a third pipe is added and all three are used to fill the pool , it takes only 6 hours. Find how long it takes the third pipe todo the job.

62. ## Social Studies

Which of the following technologies required the measurement of the stars for navigation? A. compass** B. lateen C. Mercator projection D. astrolabe

63. ## Pre-Calculus

f(x) = cos(x) on the interval [−2π, 2π] (a) Find the x-intercepts of the graph of y = f(x). (Enter your answers as a comma-separated list.) (b) Find the y-intercepts of the graph of y = f(x). (Enter your answers as a comma-separated list.) (c) Find the

64. ## math 10

a British researcher developed a formula to determine walking or running speed based on hip height and stride length. The formula is s= 0.78l ^1.67/ h^1.17 where s is speed in meters per second l is stride length in meters, and hi is the individual hip

65. ## chemistry

calculate the mass of potassium hydrogen phthalate needed to prepare a 0.1M solution in a 250 ml volumetric flask given that the molar mass of potassium hydrogen phthalate is 204,23g/mol

66. ## physics

A wagon is rolling forward on level ground. Friction is negligible. The person sitting in the wagon is holding a rock. The total mass of the wagon, rider, and rock is 94.0 kg. The mass of the rock is 0.350 kg. Initially the wagon is rolling forward at a

67. ## physics

Use R = 8.2 × 10–5 m3 atm/mol K and NA = 6.02 × 1023 mol–1. The approximate number of air molecules in a 1 m3 volume at room temperature (300 K) and atomospheric pressure is:

68. ## Algebra I

Write is y=1/6 X +4 in standard form using integers a. -x -6y =24 b. -x+6y = 24 c. -x +6y =4 ***** d. 6x-y=24

69. ## Chemistry (Re-post)

A solution contains 1.694 mg of CoSO4 (MW 155.0) per mL. Calculate a) The volume of 0.008640 M EDTA needed to titrate a 25.00 ml aliquot of this solution. So this is my working out for this section, Step 1. Moles of CoSO4 = 0.0001694mg * 25mL *

70. ## Analytical Chemistry

Phosphoric acid is a triprotic acid with the following pKa values: pka1: 2.148 pka2: 7.198 pka3: 12.375 You wish to prepare 1.000 L of a 0.0100 M phosphate buffer at pH 7.45. To do this, you choose to use mix the two salt forms involved in the second

71. ## physics

Two Children,A and B, fire identical 10g ball bearing from a catapult. The elastic band of each catapult is elastically extended by 0.10m and then released to fire a the ball bearings. Child A's elastic band has a spring constant of 144 N/m. Calculate the

72. ## Chem II

PCl5 dissociates according to the reaction: PCl5(g) ↔ PCl3(g) + Cl2(g). One mole of PCl5 was placed in one liter of solution. When equilibrium was established, 0.5 mole of PCl5 remained in the mixture. What is the equilibrium constant for this reaction?

73. ## Physics

An electron is acted upon by a force of 7.00×10−15 N due to an electric field. Find the acceleration this force produces in each case: The electron's speed is 1.00 km/s . a=??m/s2 The electron's speed is 2.50×108 m/s and the force is parallel to the

74. ## Trignometry

In Philadelphia the number of hours of daylight on day t (t is the number of days after january 1) is modeled by the function L(t)= 12+2.83sin((2*Pi)/365(t-800) a. Which day have about 10 hours of daylight? b. How many days of the year have more than 10

75. ## LA

How is Barrio Boy characteristic of nonfiction and "A Day's Wait" characteristic of fiction? Ernesto in Barrio Boy is a believable character, while the boy in "A Day's Wait" is not believable.

76. ## Chemistry

What is the activity coefficient of H^+ in a solution containing 0.073 M HCl and 0.0090 M Ca(ClO4)2? What is the pH of the solution? I believe I have to find the ionic strength of the solution first, but I don't know how to find it when 2 solutions are

77. ## Analytical Chemistry

How many milliliters of 0.0560 M EDTA are required to react with 50.0 mL of 0.0170 M Cu^2+? With 50 mL of 0.0170 M Sc^3+? My work so far: (50mL)(0.0170mmol/mL)= 0.85 mmol Cu^2+ I'm not sure how to do the rest. Please help.

78. ## Trigonometry/Geometry

In most geometry courses, we learn that there's no such thing as "SSA Congruence". That is, if we have triangles ABC and DEF such that AB = DE, BC = EF, and angle A = angle D, then we cannot deduce that ABC and DEF are congruent. However, there are a few

79. ## physics

In a police ballistics test, a 10.0-g bullet moving at 300 m/s is fired into a 1.00-kg block at rest. The bullet goes through the block almost instantaneously and emerges with 50.0% of its original speed. What is the speed of the block just after the

80. ## math

What percent of 94 is 23? A.n/94=23/100 B.23/94=n/100 C.94/n=23/100 D.23/94=100/n

81. ## Physics

As seen from above, a playground carousel is rotating counterclockwise about its center on frictionless bearings. A person standing still on the ground grabs onto one of the bars on the carousel very close to its outer edge and climbs aboard. Thus, this

82. ## Algebra 1 I need help!!!!!!!!!!!!!!!!

8.A number raised to a negative exponent is negative. Is it always , never, or sometimes. 7. Evaluate 1/2a^-4b^2 a = -2 and b = 4 remember a^to the negative 4 6. Simplify. Write in scientific notation. (9 x 10^-3)^2 Thanks to anyone who helps right away

83. ## Physics

A basketball player is running at 5.00 m/s directly toward the basket when he jumps into the air to dunk the ball. He maintains his horizontal velocity. (a) What vertical velocity does he need to rise 0.750 meters above the floor? (b) How far from the

84. ## Chemistry

Why is (E)-1,2-diisopropylethene more stable than (Z)-1,2-diisopropylethene? Why are they more stable than 1,1-diisopropylethe? And doesn't the bond angle between the C=C-C carbons increase with (Z)-1,2-diisopropylethene > (E)-1,2-diisopropylethene >

85. ## chemistry

What substance is produced at the cathode during the electrolysis of molten calcium bromide, CaBr2? Assume standard conditions.

86. ## Math

Becky and James have a total of 4 2\8 feet of yarn.Becky has 1 5\8 feet of yarn.how many feet of yarn does James have?

87. ## Language Arts 6A

Which of theses is a category used in the passage to contrast falcons and hawks?

88. ## science

At 3:15 one afternoon, the temperature over the land reaches its highest value for the day — about 89°F. The temperature over the adjacent water is about 72°F. What would the expected weather conditions be at this time? A. Cloudy skies and a sea breeze

89. ## physics

If a boat and its riders have a mass of 800 kg and the boat drifts in at 1.5 m/s how much work does Sam do to stop it?

90. ## Static Friction..I really Have no Idea

A 0.40 kg block rests on a desk. The coefficient of static friction is 0.20. You push the side of the block but do not have a spring scale to measure the force you use. The block does not move. Which statement is true about the force of static friction? It

91. ## Math

Multiply & write in simplest form: The mississippi river is about 23/25 the length of the missouri river. If the missouri river is 2,540 miles long, how long is the mississippi river? Thanks

92. ## physics

A piano wire has length L and mass M. If its fundamental frequency is f, its tension is: i got T=(lambda*f)^2m/L, but their answer is 4LMF^2 and i cant figure out how to get that

93. ## Physics

A skateboarder shoots off a ramp with a velocity of 6.7 m/s, directed at an angle of 53° above the horizontal. The end of the ramp is 1.0 m above the ground. Let the x axis be parallel to the ground, the +y direction be vertically upward, and take as the

94. ## math

In 6 hours,an experienced cook prepares enough pies to supply a local restaurant's daily order. Another cook prepares the same number of pies in 7 hours. Together with a third cook, they prepare the pies in 2 hours. Find how long it takes the third cook to

95. ## Math

An equilateral trapezoid ABCD with height 2 units has all its vertices on the parabola y=a(x+1)(x−5). What is the value of a, if points A and D belong to the x−axis and m∠BAD=30o?

96. ## Chemistry

A decomposition reaction has a rate constant of 0.0019 yr -1. ( a) What is the half-life of the reaction? ______ yr (b) How long does it take for [reactant] to reach 12.5% of its original value? ______ yr

97. ## Biology

In the small intestine, the digestion of food molecules is completed and absorption occurs. Structures from the circulatory system are associated with the small intestine. Explain how these structures assist the small intestine in its function.

98. ## Math

2. A researcher tagged 40 giant turtles in 2008. In 2009 she returned and captured 50 turtles, 16 of which were tagged. in 2010 she returned again and captured 30 turtles 8 of which were tagged. a: Use a proportion to estimate the turtle population for