1. chem help ASAP!!!!

    What ions are very important for the proper fuctioning of biological systems such as nerves and cells? A)alkali earth metals B)hydrogen ions C)oxygen ions D)nitride ions E)alkali metal ions my choice is A or C can anyone help?
  2. Writing I

    Label each sentence below. Use S for simple, CD for compound, CX for complex, and CD-CX for compound-complex. 1. Do you know the theory of black holes? 2. Objects in space have gravitational pull, so smaller objects are attracted to larger object. 3. Throw
  3. spanish

    Part 4—Listening Comprehension Directions: Listen to this short story called “What ought a man to do on earth?”—¿Qué debe hacer sobre la tierra un hombre? You will hear the story two times. After listening to the story, answer these questions.
  4. Physics

    A) Gravity pulls an area of wet soil and rock downward in a landslide B) An ... Many people know that the weight of an object varies on different planets, but did ... If the Earth's gravitational force causes a falling 74 kg student to accelerate .... the
  5. math

    on earth, in the absence of air, the rock in excersise 13 would reach a height of s=24t- 4.9t^2 meters in t seconds. How high would the rock go? (exercise 13:a rock thrown vertically upward from the surface of the moon at a velocity of 24m/sec reaches
  6. Physics

    Suppose the density of the Earth was somehow reduced from its actual value to 1300 kg/m3. What would be the value of g, the acceleration due to gravity, on this new planet? Assume the radius does not change. I know that density = mass/volume & the volume
  7. geology(science) does this sound ok?

    write a 200-300 word description of how these four subsystems interact with one another. In your response, identify one type of resource from each subsystem on which people depend. this is what i said..... The earths 4 subsystems are the following
  8. English

    I left out these few statements on the themes I would like you to check. Thank you very much. 1.Macbeth is the shortest of S’s tragedies; it is simple in its plot but complex in its psychological analyses of what takes place in the mind of the criminal.
  9. Earth Science

    1. In the classroom during a visual inspection of a rock, a student recorded four statements about the rock. Which statement about the rock is an observation? (1)The rock formed deep in Earth’s interior. (2)The rock cooled very rapidly. (3)The rock
  10. Science: Plate Techtonics (giving out medals)

    Hey there! I need help with some answers 1. Why do earthquakes occur along the San Andreas fault line? 2. Which of the following causes Earth's plates to move continuously? 3. Which of the following physical features are not caused by plate tectonics?
  11. Science

    1. Where is the Earth's equator located today? Describe the climatic conditions. 2. Compare and contrast the climatic conditions existed during this time today. 3. Answer: What types of fossils would you expect to find here? Explain why based on the
  12. General Chemistry I

    At noon on a clear day, sunlight reaches the earth's surface at Madison, Wisconsin, with an average power of approximately 4.00 kJ·s–1·m–2. If the sunlight consists of photons with an average wavelength of 510.0 nm, how many photons strike a 6.60 cm2
  13. Science

    How did the brightness or intensity of the light change as the degree of tilt increased? Which degree of tilt produced light similar to what North America experiences in the summer? What would be the effect on the seasons and the northern and southern
  14. Geometry

    A sailboat is heading directly north at a speed of 16 knots (1 knot = 0.514 m/s). The wind is blowing towards the east with a speed of 10.4 knots. (Both velocities are given relative to the Earth.) Determine the magnitude and direction of the wind velocity
  15. physics111

    a river flows due south with a speed of 2.0m/s. a man steers a motorboat across the river;his velosity is 4.2m/s due east.the river is 800m wide. (A) what is his velocity(magnitude and direction)relative to the earth? (B)how much time is required to cross
  16. Social Studies

    Which of the fallowing is not true about Aborigine culture? a. It is the oldest surviving culture on Earth*** b. Tradition Aborigine societies found agricultural settlements c. Aborigine do not believe that land belongs to humans d. Aborigine groups are
  17. physics

    explain the law of motion needed to slove this problem. On Planet Zorg, a 30kg barbell can be lifted by only exerting a force of 180N. what is the acceleration of gravity on Planet Zorg? Predict how the motion of this object would change on earth.
  18. Satistics

    1.A large electronics company wants to estimate the proportion of all households that own GPS machines. What sample size is required that would give the maximum error of 2.0% for a 95% confidence interval? An unscientific survey had an initial result of
  19. English

    Could you please check these two sentences, please? 1) Water chute and spring board don't have the same meaning, but I think I can use them both with "dive into the water". 2) Superman was both a superhero endowed with superpowers and a shy and insecure
  20. Science (check my answers)

    14. Chemical runoff from fields, oil spills, and erosion is the major source of a. air pollution b. water pollution*** c. hydropower d. renewable energy 15. Which compound causes the depletion of earth's ozone layer? a. ultraviolet radiation*** b.
  21. True or False?

    Sounds like an easy question but I just wanna be sure! :P Tides are caused by the force of inertia from the sun and moon acting on Earth. True or False? I think its false because its gravity not inertia.
  22. modern physics

    A star emits light with wavelength 120 nm. An observer on earth measures the wavelength of the light received from the star to be 600 nm. Calculate the speed with which the star is moving.
  23. physic

    Assuming uniform density, how much would 1.1 cubic centimeters of neutron star material weigh on the surface of the earth? You need the density of the neutron star to do this. weight= mass*g=density*volume*g
  24. Physics

    An image of the moon is focused onto a screen using a converging lens of focal length f= 35.3 cm. The diameter of the moon is 3.48×106 m, and its mean distance from the earth is 3.85×108 m. What is the diameter of the moon's image?
  25. English

    In this sentence Plenty of silicon is found on Earth, but it remains a valuable material for the computer industry. I'm still not sure if the simple subject is plenty or silicon, but I think it's silicon because the second part of the sentence says it.
  26. 9th grade (math)

    the surface of our earth is 20'c for every km, k below the surface the tempature increses by 10'c. let t represent the tempature in 'c 1a write an equation that represent the relationship between disatnce k and t tempature 1b. what is the slope and and
  27. Physics

    A helicopter is ascending vertically with a speed of 5.00 m/s. At a height of 120 m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? v_0 for the package equals the speed of the helicopter
  28. Earth

    1. The great galaxy in Andromeda has an angular diameter along its long axis of about 5^0. Its distance is about 2.2 million light years. What is its linear diameter? angle*distance= arc distance. You need the angle in radians to do this.
  29. physics

    a helicopter is ascending vertically with a speed of 5.20 m/s. at a height of 100 m above the Earth, a package is dropped from a window. how much time does it take for the package to reach the ground ? (hint: v0 for the package equals the speed of the
  30. geography

    Which statement below are examples of human geography "Except"! A. interaction patterns between people B. People's minds and thought processes C. people's interaction within the community. D. Earth's various climates and multiple layers of atmosphere.
  31. physics

    a helicopter is ascending vertically with a speed of 5.20 m/s. at a height of 110 m above the Earth, a package is dropped from a window. how much time does it take for the package to reach the ground ? (hint: v0 for the package equals the speed of the
  32. Science

    In the Earth Science Reference Tables (you can find them at google), on pg 11 on the bottom where there's the Earthquake Travel Time Graph, on the y-axis, what does each box equal? like for the x-axis, each box between 1 and 2, and 2 and 3 is 200 km, what
  33. Physics

    A helicopter is ascending vertically with a speed of 4.50 m/s. At a height of 65 m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? [Hint: The package's initial speed equals the
  34. Math

    The distance to the nearest 100000 km from Earth to the moon is given as 400000 km.The average speed to the nearest 500 km/h of a rocket to the moon is given as 3500 km/h.Calculate the greatest and least time it could take the rocket to reach the moon.
  35. physics

    A helicopter is ascending vertically with a speed of 6.50 m/s. At a height of 55 m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? [Hint: The package's initial speed equals the
  36. physics

    Can a person, in principle, travel from Earth to the galactic center (which is about 2.3e4 lightyears distant) in a normal lifetime? Explain, using either time-dilation or length contraction arguments. If they want to make the trip in 24 y what distance
  37. Physics

    At high noon (sun rays fall perpendicular to the surface of the earth), the sun delivers 990 W to each square meter of a blacktop road, emissivity of 1 (blackbody). If the hot asphalt loses energy only by radiation, what is its equilibrium temperature? I
  38. Earth's Dynamic Atmosphere

    Which one of the following statements is true about the equinoxes? A. They occur in June and December. B. Days and nights are equal in length everywhere. C. The length of daylight at the Arctic and Antarctic Circles is 24 hours. D. The Sun's vertical rays
  39. Math

    The slowest mammal on Earth is the sloth. A sloth might move along a tree at a maximum rate of just 3 ^-1m each minute. At this rate, how long will it take a sloth to climb a tree that is 33 m tall?
  40. Science

    what are spring tides and how do they occur? Spring tides are are very high tides which occur when the sun, moon, and earth form a straight line. Please correct me if I'm wrong, thanks :-)
  41. physics

    An accelerometer is a device that uses the extension of a spring to measure acceleration in terms of Earth's gravitational acceleration (g). What is the approximate acceleration if this accelerometer spring is extended just 0.43 centimeters?
  42. Earth Science

    A student finds the density of an ice cube to be 0.80g/cm3; it is actually 0.90 g/cm3. What is the percent deviation (percent error) in this calculation? (1)6 percent (2)11 percent (3)13 percent (4)88 percent (2)?
  43. astro

    The intensity of an object is related to the distance d to the observer by the equation (I1/I2) = (d2/d1)2. If the apparent magnitude of the Sun seen from Earth has a value of -26.74, what is the apparent magnitude of the Sun seen from Neptune (30AU from
  44. math

    The basement of a new home will have the following dimensions 30 feet long 24 feet wide and 9 feet deep If the earth is hauled away in loads of 3 cubic yards each, how many loads must be hauled away?
  45. physics

    Which is true as one gets closer to the center of the earth? a. The person’s weight increases b. The person’s weight decreases c. The person’s weight remains the same d. The person’s mass changes e. A new dimension is discovered
  46. SCIENCE,PHYSICS

    Exact solutions for many-body problems are rarely encountered in physics. The following problem deals with a non-trivial motion of four charges. Due to the symmetry of the problem it is possible to determine the trajectories of the charges analytically.
  47. Physics (help steve)

    Exact solutions for many-body problems are rarely encountered in physics. The following problem deals with a non-trivial motion of four charges. Due to the symmetry of the problem it is possible to determine the trajectories of the charges analytically.
  48. Physics

    A helicopter is ascending vertically with a speed of 5.20 m/s. At a height of 125 m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? [Hint: The package's initial speed equals the
  49. phy

    A helicopter is ascending vertically with a speed of 5.50 m/s. At a height of 155 m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? [Hint: The package's initial speed equals the
  50. Science

    Earth's energy sources include both renewable and nonrenewable resources. Name at least three sources of energy that could be used in your house. Then describe the ideal energy source for generating most of your home's electricity, and explain why you
  51. intro. to physics

    a helicopter is ascending vertically with a speed of 5.20 m/s. at a height of 100 m above the Earth, a package is dropped from a window. how much time does it take for the package to reach the ground ? (hint: v0 for the package equals the speed of the
  52. Physics

    A hydrogen atom is at the earth's surface. The electron and proton in the atom are separated by a distance of 5.29x10^-11m. What is the ratio of the magnitude of the electrical force exerted by the proton on the electron to the weight of the electron?
  53. physics

    A helicopter is ascending vertically with a speed of 4.50 m/s. At a height of 195 m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? [Hint: The package's initial speed equals the
  54. Calculus

    Math questions, please help me? :(? Find the composite functions f o g and g o f for the given functions. f(x) = 10^x and g(x) = log x State the domain and range for each: f(x) = 4x + 1 and g(x) = x^2 f(x) = sin x and g(x) = x^2 - x + 1 f(x) = 10^x and
  55. Science

    "Earth's energy sources include both renewable and nonrenewable resources. Name at least three sources of energy that could be used in your house. Then describe the ideal source of energy for generating most of your home's electricity, and explain why you
  56. physics please help !

    A helicopter is ascending vertically with a speed of 5.20m/s . At a height of 110m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? [Hint: for the package equals the speed of the
  57. science

    Earth's energy sources include both renewable and nonrenewable resources. name at least three sources of energy that could be used in your house. then describe the ideal energy source for generating most of your home's electricity, and explain why you
  58. Chemistry

    A new element, Canadium, not found on earth, contains 3 isotopes. given the following information, calculate the atomic mass of Canadium. Isotope Mass (amu) % abundance 1 429.633 21.29 2 429.121 42.47 3 429.398 ?
  59. physics

    A helicopter is ascending vertically with a speed of 5.20 m/s. At a height of 120 m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? [Hint: v_0 for the package equals the speed of the
  60. physics!

    Recently, a meteor impacted Russia. The estimate of the meteor's size was 10 tons and it was estimated to have entered the earth's atmosphere at a speed of 14,600 m/s. What was the total kinetic energy of such a meteor in J as it entered the atmosphere?
  61. Physics

    You are hitting a tennis ball against a wall. The 0.057-kg tennis ball traveling at 29 m/s strikes the wall and rebounds at the same speed. Earth is the object of reference. Determine the ball's change in momentum (magnitude).
  62. Physics

    A helicopter is ascending vertically with a speed of 3.00 m/s. At a height of 70 m above the Earth, a package is dropped from a window. How much time (in seconds) does it take for the package to reach the ground? [Hint: The package's initial speed equals
  63. American History

    Hello I just got done with a homework assignment in American History and there is this one question that has been bugging me: Which of the following is true of the columbus legend? a. He was the only voyager who believed the Earth was round. b. He was the
  64. physics

    apollo astronaunts took a nine iron to the moon and hit a golf ball about 180 m ! Assuming that the swing, launch angle, and so on, were the same as on earth where the same astronaut could hit it only 35 m, estimate the acceleration due to gravity on the
  65. physics

    A long, straight wire lies on a horizontal table and carries a current of 3.05 µA. In a vacuum, a proton moves parallel to the wire (opposite the current) with a constant speed of 3.00 104 m/s at a distance d above the wire. Ignoring the magnetic field
  66. Physics

    a ship is headed towards east at a thrust speed of 7.00 knots. A strong wind pressure causes the ship to deviate to the north at 1.00 knots. The sea current is flowing to the southwest at 4.00 knots. Determine the velocity of the ship relative to the
  67. science

    Given that Antarctica is roughly semicircular with a radius of 2000 km and has an average ice thickness of 3000 m. a) How many km3 of ice does Antarctica contain? b) Assuming all the ice melts, how much will this raise sea level (ignoring that the Earth
  68. math

    p=14.63⋅0.8 Atmospheric pressure, measured in pounds per square inch p, s, i is the force exerted by Earth's atmosphere over a given area. The atmospheric pressure, p, exerted on an airplane flying at an altitude of a miles above sea level can be
  69. Physics

    Assume the Earth is a perfect sphere of radius 6,400 kilometers. Find the weight of a 75.0 kg person at the North pole. Find the weight of this same person at the equator. (You don't need to use Newton's Law of Gravitation but you do need to analyze the
  70. science

    earth and the moon are kept in their respective orbits due to the influence of ? a) inertia b) gravity c) both inertia and gravity d) neither inertia and gravity
  71. Logic

    Even if you know only some of them please help! 1. Give a proof of the following: (∀F)( (P)( [ιxGx][Px] ⊃ F(P) ) ⊃ F(G)) (∃F)( (P)( F(P) ≡ [ιxGx][Px]) Therefore, E!(ιxGx) 2. Prove the following:
  72. science

    Earth's energy sources include both nonrenewable and renewable resources. Name at least three sources of energy that could be used in your house. The describe the ideal energy source for generating most of your home's electricity, and explain why you chose
  73. Physics

    A helicopter is ascending vertically with a speed of 5.20 m/s. At a height of 125 m above the Earth, a package is dropped from a window. How much time does it takes the package to hit the ground? [Hint: The package's initial speed equals the helicopter's]
  74. Physical Science

    This is the question in my homework: In orbiting the Earth, what kind of motion is it, uniformly velocity, uniformly accelerated or non-uniformly accelerated motion? I have searched for almost an hour on the internet in any variety of those terms I could
  75. EAPS

    Consider what happens to a solar beam traveling through the atmosphere on some particular day. Within the atmosphere, 15% of the radiation is absorbed and 20% is scattered or reflected to space mostly by clouds. What percent of the solar radiation incident
  76. E.L.A. PLEASE CHECK!

    Which choice best describes the underlined word or words in each sentence? For several decades, satellites around the earth have broadcast signals and monitored weather. Underlined is: satellites A- complete subject B- simple subject C- compound subject D-
  77. physics

    above the earth, a 500nT magnetic field captures particles coming from the sun. If a proton moving at 600km/s runs into this magnetic field, what is the radius of motion of the proton? and also how long does it take the proton to travel in one circle?
  78. physics

    The tropospheric lapse rate (the rate at which temperature decreases with altitude) is approximately 6°C per kilometer. Given that the mean surface temperature of Earth is 288 K and the effective radiating temperature is 255K, from what altitude does most
  79. Physics

    a) Calculate the acceleration due to gravity on the planet Mars. I found this to be about 3.7 m/sec^2 b) What would your weight be on the planet Mars if you weighed 130 lbs? c) If you could jump vertically 5 ft on earth, how high would you be able to jump
  80. science

    a body is released from the great height and falls freely towards the earth . another body is released from the same height , one second later . then the separation between the two bodies , two seconds after release of the second body is
  81. french

    I have to write a paragraph in french about who i am where i live and what pets i have,my name is Harry White I am 12 years old I live in Buckingham and have 2 dogs 5 cats how on earth do I write that in french
  82. Physics

    A planet with mass 7 x 1024 kg orbits a sun with a period of 1 Earth's years. The speed of the planet around that sun is constant and |v|=43000 m/s. What is the mass of that sun?
  83. physics

    Gravitational Attraction 1. The centers of two 11.80 kg spheres are separated by 0.09 m. What is their gravitational attraction? 2. What is the ratio of this attraction to the weight of one of the spheres (at the surface of the Earth)? Please answer both,
  84. physical

    The mass of the earth is 5,96 multipy by 10 to the power of 2) kg and that of the moon 7,35 multiply by 10 to the power of 22kg.If the distance between their centres is 3,84 multiply by 10 to the power of 8m,calculate the mass of each ball.
  85. math

    A trench 4 meter long ,2 meter wide and 3 meter high was dug into the ground.find the volume of the earth dug out for making this trench.
  86. physical

    The mass of the earth is 5,96 multipy by 10 to the power of 2) kg and that of the moon 7,35 multiply by 10 to the power of 22kg.If the distance between their centres is 3,84 multiply by 10 to the power of 8m,calculate the mass of each ball.
  87. Science

    What are neap tides, and why do they occur? Neap tides are the weaker tides. They occur when the sun and the moon are perpendicular to each other with respect to earth. Please correct me if I'm wrong, thanks
  88. science

    How can I write a 500 word essay on what agriculture means to me by comparing the pros and cons of early 1900's agriculture, the industrial war, effects of chemical warfare on the agriculture industry, including people, animals, the earth, while basing
  89. Earth Science Continued

    Please help me with the following questions: 1. A scientist suspected that the increase in the acidity of ocean water could have a devastating effect on organisms such as snails because it could break down calcium carbonate, a chemical that makes up their
  90. Symbolic Logic

    Even if you know only some of them please help! 1. Give a proof of the following: (∀F)( (P)( [ιxGx][Px] ⊃ F(P) ) ⊃ F(G)) (∃F)( (P)( F(P) ≡ [ιxGx][Px]) Therefore, E!(ιxGx) 2. Prove the following:
  91. earth science

    how is the andean type subduction zone different from the aleutian type subduction zone? are there pictures?
  92. science

    wat causes an apple to fall down from a tree a pulling force towards the tree or a pulling force towards the earth
  93. Science please help thx

    Convection cells are created by very hot material deep in the mantle rising, then cooling, sinking again and repeating the cycle. This process occurs because of the uneven distribution of ? Within the earth? Please fill in the question mark with a answer.
  94. science + check over

    please check my answers + help me improve them. * 1.) explain why earth & other planets were not solid when they formed during the beginning of the precambrian, approximately 4,600 million years ago + what was this particular time period called & why is
  95. Chemistry

    The petrol, can be represented by the formula of the octane rating, has earth specifies 704 g/L. Estimate the enthalpy variation when burning 28.5 liters of petrol, assuming energies of connection 0 = 0 (117 kcal) C = 0 (173 kcal) 0–H (111 kcal) C–C
  96. Science

    Suppose we allowed each person 1000m^3 of living space in a large building, with ceiling height 3 m. To the nearest order of magnitude, how many 1000m high buildings would have to be built to house the entire population of 8.5 x 10^14 people on the
  97. calculus

    newtons law of gravitation says that the magnitude F of the force exerted by a body of mass m on a bod of mass M is F=GmM/r^2 where G is the gravitational constant and r is the distance between the bodies. a)find dF/dr and explain its meaning. What does te
  98. Elementary lesson

    I want my readers to understand that water has been around from the beginning of time. I want them to understand that the earth is constantly recycling the water and that the waters that dinasours drank millions of years ago, is the same one that we are
  99. Geology/Earth Science

    1. In what climate and on what rock type would you expect a)Karst formation b)Crystal growth; to occur? 2. Explain the process by which potholes in a road get bigger. 3. Why in central Ontario, does the south and southwest side of a building weather faster
  100. physics

    An electric power line carries a current of 1600 A in a location where the earth's magnetic field is 4.0*10-5 T. The line makes an angle of 75° with respect to the field. Determine the magnitude of the magnetic force on a 130 m length of line.