1. Physics

    Calculate the effective value of g, the acceleration of gravity, at 6400m , above the Earth's surface. Calculate the effective value of g , the acceleration of gravity, at 6200km , above the Earth's surface

    asked by Lea on October 2, 2009
  2. hypothesis test

    I am confused on what statistic test I should perform. I think it should be the t-test, which I have provided below. If the t-test is correct, how do I decide if I need to reject the null hypothesis. I get really confused on these things. Null Hypothesis:

    asked by mchawk on January 26, 2009
  3. Biology

    1. Which of the following is the definition of ecology? the social movement with a goal to protect the environment the recycling of human-made materials to reduce waste going into landfills the study of interactions among organisms and between organisms

    asked by Anon on August 24, 2012
  4. math

    The position of two towns X and Y are given to the nearest degree as X(45° N, 10° W) and Y (45 N°, 70° W). Find (a) The distance between the two towns in (i) Kilometers ( take the radius of the earth as 63711) (ii) Nautical miles ( take I nautical mile

    asked by kudu on February 9, 2015
  5. Chem

    From the information below, identify element X. a. The wavelength of the radio waves sent by an FM station broadcasting at 97.1 MHz is 30.0 million (3.00 X lo7) times greater than the wavelength corresponding to the energy difference between a particular

    asked by Dianne on March 29, 2007
  6. reading

    Scientists generally agree that Earth is getting warmer due to what's called the greenhouse effect. A greenhouse used for plants stays warm because sunlight and heat coming through the glass roof are mostly trapped. The heat doesn't radiate back into the

    asked by Anonymous on January 30, 2015
  7. earth science...help

    for this question: Put the folloing words together in a few sentence to explain their meaning and relationship to one another: seismic waves, seismograms, seismoghaps, and seismologists. is this answer suitable: Seismic wave is an elastic shock wave that

    asked by Anonymous on January 13, 2009
  8. Geography

    question: Describe the various types of forest vegetation make sure to give good examples of location and type of plants. answer: There are various types of forest vegetations located around the world. Tropical rain forests grow in areas near the equator,

    asked by y912f on January 7, 2010
  9. physics

    A 85 kg rock climber first climbs 50 m up to the top of a quarry, then descends 75 m from the top to the bottom of the quarry. If the initial height is the reference level, find the potential energy of the system (the climber plus Earth) when the climber

    asked by Merlin on May 11, 2011
  10. History

    Which accurately describes exploration events of Sir Francis Drake? drake found a northwest passage to Asia through present-day Canada drake sailed to the new world and founded the colony of Jamestown drake sailed north along the coast of Greenland to find

    asked by malia on October 27, 2017
  11. social studies

    general lee go on the offensive against the north?

    asked by kail on October 27, 2009
  12. History

    What time of year does snow come to the far north?

    asked by Danny on January 21, 2015
  13. social studies

    what is the longest river in the north america?

    asked by katie on September 18, 2008
  14. science

    what is the momentum of a 57 kg cheetah running north at 27 m/s?

    asked by ada on November 18, 2010
  15. U.S. History

    Why do you think canals were more common in the North than in other areas?

    asked by Victoria on September 17, 2015
  16. social studies

    Is the Artic Circle north of the equator?

    asked by Reed on August 30, 2010
  17. Social studies

    1. In The AD 600s north Africa was conquered by

    asked by HELP PLEASE I AM NOT DOING WELL IN S.S PLEASE HELP on October 11, 2017
  18. Social Studies

    Which three countries makes up most of North America?

    asked by joshua on September 20, 2012
  19. Social Studies

    What did the north call the battle of Manassas?

    asked by Neon on April 24, 2012
  20. geography>3

    why might many of the region's rivers flow toward the north?

    asked by hannah on October 5, 2013
  21. social studies

    the waterway that extends north of the dead se what is

    asked by kaitlynn on September 30, 2009
  22. social studies

    how people settled in north america?

    asked by dasia on September 22, 2009
  23. Geography

    Is Greenland part of North America?

    asked by Celest on July 8, 2014
  24. Social Studies

    did the people in the north have slaves in the 1800s?

    asked by I know this on December 19, 2017
  25. 7th grade

    I would like to know about the history of the omads of North Aerica?

    asked by Stephen Fleary on October 6, 2009
  26. physics

    a pilot has to go 35 km east then 50 km due north

    asked by Lynn on February 4, 2011
  27. social studies

    what city is closest to 34 north and 81 west.

    asked by Anonymous on May 24, 2018
  28. science

    Could you see the North Star in the southern hemisphere

    asked by pam on February 16, 2011
  29. 2nd grade

    what is largest city in north america?

    asked by bhavin on December 17, 2008
  30. history

    The first humans who migrated to North America came on what?

    asked by Amber on September 16, 2007
  31. history

    When were the colonial ages in North America?

    asked by Anonymous on September 20, 2008
  32. Geography

    What is the second longest river in North America?

    asked by Emily on September 21, 2010
  33. social studies

    what is North Carolina largest port

    asked by isaiah on January 8, 2013
  34. social studies

    Who were some of the French explorers who came to North America?

    asked by autumn on April 20, 2010
  35. Math

    What are the coordinates when its 25 km/hr at 27 degrees north of east?

    asked by Liezel Matias on January 7, 2011
  36. History

    homo sapiens came to north america by...????

    asked by Justin on August 24, 2011
  37. More related rates.

    Heyy, its me again. So last night I asked a related rate question, and I think I still don't get it. I tried it a few differnt ways and I think I'm just missing something...I don't think a speed of a rocket can be 0.018km/hr:S. So heres what happened: A

    asked by Tracy on November 3, 2006
  38. Science , Biology

    Cretaceous extinction... The evidence tells you that “overwhelming evidence suggests that the extinction was caused by a 10-km-diameter asteroid that struck Earth.” Suggest at least three lines of evidence that might have led scientists to this

    asked by Woo on November 27, 2016
  39. Science

    In the early 1900s, Alfred Wegener noticed that some of the Earth's continents looked like they might fit together like a jigsaw puzzle. He also observed that the continents that looked like they fit together had similar plants, animals, and rock

    asked by Christina on August 15, 2014
  40. 8th grade Science

    In the early 1900s, Alfred Wegener noticed that some of the Earth's continents looked like they might fit together like a jigsaw puzzle. He also observed that the continents that looked like they fit together had similar plants, animals, and rock

    asked by M on September 29, 2013
  41. chemistry

    what fraction of the total mass of an 56 Fe atom is due to the electrons? The mass of a proton is 1.673 x10-24 g, of a neurton 1.675 x 10-24 g, an of an electron 9.109 x 10-28g.

    asked by ducky on September 26, 2010
  42. Chemistry

    In every electrolytic and galvanic (voltaic) cell the anode is that electrode (A) at which oxidation occurs. (B) which attracts cations. (C) at which electrons are supplied to the solution. (D) at which reduction occurs.

    asked by LT on May 12, 2008
  43. Physical Chemistry

    Derive an expression for number of electrons N(E) with energy that can escape from a metal in terms of Z(E) (density of state) and F(E) (Fermi-dirac function) and ф (work function).

    asked by John on November 18, 2011
  44. physics

    A 0.10 g plastic bead is charged by the addition of 1.0 x 1010 excess electrons. What electric field (strength and direction) will cause the bead to hang suspended in the air?

    asked by Jessika on July 21, 2011
  45. physics

    If you were to separate all of the electrons and protons in 1 g (0.001 kg) of matter, you’d have about 96,000 C of positive charge and the same amount of negative charge. If you placed these charges 5 m apart, how strong would the attractive forces

    asked by olga on May 5, 2011
  46. physics

    How many excess electrons must be distributed uniformly within the volume of an isolated plastic sphere 28.0 in diameter to produce an electric field of 1500 just outside the surface of the sphere?

    asked by How many excess electrons must be distributed unif on February 10, 2010
  47. Chemistry

    If 2moles of electrons are required to oxidize 1 mole of unknown, what is the molarity of the unknown solution Normality: 0.638 In this experiment: MnO4- is reduced to Mn2+

    asked by unknown on April 9, 2008
  48. Physics PLEASE HELP

    When UV light of wavelength 295nm falls on a metal surface, the maximum kinetic energy of emitted electrons is 1.50eV. What is the work function of the metal? W0 in eV

    asked by Sheila on April 24, 2013
  49. physics

    If 1000 electrons are removed from an isolated neutral metal sphere, calculate the charge acquired by the sphere. -1 mark question of state syllabus.

    asked by Angela on October 17, 2016
  50. Chemistry

    The standard electrode potentials for three electrode systems are: Ti^3+(aq) + e^- --> Ti^2+ E= -0.37 Fe^3+ ---> Fe^2+(aq) E= +0.77 Ce^4(aq) + e^- ---> Ce^3+(aq) E= +1.45 Using the data above, deduce which species is the best reducing agent, giving a

    asked by Kari on March 15, 2010
  51. Physics

    When UV light of wavelength 295nm falls on a metal surface, the maximum kinetic energy of emitted electrons is 1.50eV. What is the work function of the metal? W0 in eV Please someone help me out. Thank you.

    asked by Sheila on April 22, 2013
  52. Physics

    Two very small spheres are initially neutral and separated by a distance of 0.50 m. Suppose that 2.50 x 10^13 electrons are removed from one sphere and placed on the other. What is the magnitude of the electrostatic force that acts on each sphere?

    asked by Melissa on September 26, 2010
  53. Physics

    When UV light of wavelength 295nm falls on a metal surface, the maximum kinetic energy of emitted electrons is 1.50eV. What is the work function of the metal? W0 in eV

    asked by Sheila on April 23, 2013
  54. chemistry

    Using electron bookkeeping draw a Lewis dot diagram for NF2H and N2H2 determine how many electrons each atom should be assigned. Thanks Guys I really appreciate it, my assignment is due tonight and the test is tomorrow, could you explain it,thanks

    asked by Will J on December 1, 2011
  55. science

    What mass of protons would be required to just neutralize the charge of 1.7 g of electrons? I thought it was simple because 1 proton maxes out 1 electron but my teacher started talking abou this complicated way of doing it and i didn't get it :( can

    asked by Lily on September 21, 2010
  56. Geography

    I have to use the given hints to find out what country they're talking about in each hint. 3. "Travled south and arrived today in the town associated closely with Hans Christian Andersen. Weather a bit rainy here, but we're having too much fun to care!" I

    asked by mysterychicken on October 11, 2009
  57. Physics

    Your dog has been diagnosed with a terminal illness for which there is no cure. The Veterinarian expects that it will live for 1 year before it succumbs to the condition. You have the idea that if you could keep the dog alive a little longer, a cure might

    asked by Jon on January 22, 2010
  58. physics180

    A satellite is in circular orbit at a height R above earth's surface. a)find orbital period. b)what height is required for a circular orbit with a period double that found in part (a)?

    asked by jaymie on November 2, 2011
  59. Physics

    A 3000kg satellite orbits the Earth 400km above the equator. find a)The speed of the satellite b) The kinetic energy of the satellite c) The potential energy of the satellite d) The total energy of the satellite

    asked by Dave on November 8, 2012
  60. Geography

    #62. Taken as a whole, what would you say is the single most pressing problem found in Latin America or South America? What possible solutions can you develop? my answer: Taken as a whole, I would say that poverty is the single most pressing problem found

    asked by y912f on February 12, 2010
  61. Physic

    A Coast Guard ship is traveling at a constant velocity of 4.13 m/s, due east, relative to the water. On his radar screen the navigator detects an object that is moving at a constant velocity. The object is located at a distance of 3900 m with respect to

    asked by Anonymous on September 30, 2015
  62. Physics

    Two boats are heading away from shore. Boat 1 heads due north at a speed of 3.7 m/s relative to the shore. Relative to boat 1, boat 2 is moving 35° north of east at a speed of 1.3 m/s. A passenger on boat 2 walks due east across the deck at a speed of 1.2

    asked by Randal on September 20, 2010
  63. acct

    Far North Telecom, Ltd., of Ontario, has organized a new division to manufacture and sell specialty cellular telephones. The division’s monthly costs are shown in the table below. Far North Telecom regards all of its workers as full-time employees and

    asked by mark t on February 21, 2012
  64. Math

    Hello ma’am sir.. I have a problem in my assignment.. I‘m now a college student…a first year student…this is my question..please help me.. I really need it now… 1. The diameter of the earth is 7920 miles, and that of the moon is 2160 miles.

    asked by Mr. J on May 6, 2010
  65. Chemistry

    From the information below, identify element X. a. The wavelength of the radio waves sent by an FM station broadcasting at 97.1 MHz is 30.0 million (3.00 e7) times greater than the wavelength corresponding to the energy difference between a particular

    asked by Gabriela on April 18, 2007
  66. social studies

    5, which statement best explains how the conflict over tariff of 1828 was resolved The US Supreme Court ruled against the tariff Daniel Webster gav a speech to the Senate and the tariff was repealed South Carolina passed the nullification Act which

    asked by m on November 16, 2016
  67. trig

    A plane has an airspeed of 200 miles per hour and a heading of 28.0°. The ground speed of the plane is 207 miles per hour, and its true course is in the direction of 38.0°. Find the speed and direction of the air currents, assuming they are constants.

    asked by bryan on November 29, 2012
  68. Geography

    Can someone please check of my answers are correct? 16. Although most of South America lies within the tropical latitudes a. climate and vegetation differ greatly in the region b. cold ocean currents keep the air cool and dry c. there is little tropical

    asked by mysterychicken on September 3, 2009
  69. chem

    In the equation: 2Al+6HCl-->2AlCl3+3H2 Why is the hydrogen by itself instead of the chlorine? Al is above hydrogen in the activity series (sometimes called the electromotive force series); therefore, it replaces H. This is single replacement type reaction.

    asked by Amie on March 18, 2007
  70. Physics help please

    You are the science officer on a visit to a distant solar system. Prior to landing on a planet you measure its diameter to be 2.070E+7 m and its rotation to be 19.8 hours. You have previously determined that the planet orbits 1.590E+11 m from its star with

    asked by Me on November 27, 2011
  71. PHYSICS!!

    A 10.2 kg crate is pulled up a rough incline with an initial speed of 1.5 m/s. The pulling force is 123.0 N parallel to the incline, which makes an angle of 14.6◦ with the horizontal. The coecient of kinetic friction is 0.39 and the crate is pulled a

    asked by billy on October 18, 2008
  72. social stuides

    What was the purpose of Jim crow laws in south Carolina? a. To stop African Americans from voting ** b. To stop poor whites from voting c. To take land for African Americans d. To help African Americans gain jobs What was the purpose of the freedmen’s

    asked by UNKNOWN on March 22, 2016
  73. physics

    On planet x, an object weighs 10.4N. On planet B where the magnitude of the free fall acceleration is 1.48g (where g=9.8 m/s^2 is the gravitational acceleration on Earth),the object weighs 24.6N. The acceleration of gravity is 9.8 m/s^2. What is the mass

    asked by alexa on July 2, 2011
  74. chem

    how many protons, nnutrons, atomic mass, mass number, and charge to each of the following have? sodium atom fluorine ion stannic ion for sodium i have protons=11 electrons=11 neutral charge how do i find the number of neutrons cause im pretty sure mass

    asked by lyne on January 7, 2009
  75. Math

    What is the probability that the next cyclone to develop in Australian waters will cross the Qld coast (Apply conditional and total probability). Condition is cyclones that cross the Qld coast are only generated in the south pacific. Cyclones generated in

    asked by Greg on April 4, 2008
  76. SOCIAL STDIES HELP!!!!!

    1. What was the New South philosophy? (1 point) a philosophy that the southern economy should become more industrialized the idea that African Americans should own more businesses*** the notion that traditional farming techniques should be maintained a

    asked by XenaGonzalez on March 30, 2015
  77. physics

    Heather and Matthew walk eastward with a speed of 0.98 m/s. If it takes them 34 min to walk to the store, how far have they walked? If Joe rides south on his bicycle in a straight line for 15 min with an average speed of 12.5 km/h, how far has he ridden?

    asked by anonymous on September 20, 2006
  78. Environmental Science

    are these correct? 29. A common feature of thermal pollution and artificial eutrophication is that they both a. ave sources that are idfficult to identify and control b. cause large mats of algae to bloom in fresh water c. are a result of power plants and

    asked by y912f on February 1, 2010
  79. Geography (Ms. Sue)

    1). In what industry do most Americans work? 2). How did California become the nation's most populous state? 3). How has the economy of the South changed? 4). How has U.S population shifted since the country began? 5). What helped the economy of the West

    asked by Anonymous on September 13, 2013
  80. physics

    On earth, two parts of a space probe weigh 19200 N and 4130 N. These parts are separated by a center-to-center distance of 6.38 m and may be treated as uniform spherical objects. Find the magnitude of the gravitational force that each part exerts on the

    asked by Anonymous on October 21, 2013
  81. Physics

    On earth, two parts of a space probe weigh 18300 N and 4440 N. These parts are separated by a center-to-center distance of 5.11 m and may be treated as uniform spherical objects. Find the magnitude of the gravitational force that each part exerts on the

    asked by Orla on October 19, 2012
  82. Physics

    On earth, two parts of a space probe weigh 17300 N and 3260 N. These parts are separated by a center-to-center distance of 19.4 m and may be treated as uniform spherical objects. Find the magnitude of the gravitational force that each part exerts on the

    asked by Briana on September 20, 2013
  83. Physics

    A 45-m length of wire is stretched horizontally between two vertical posts. The wire carries a current of 67 A and experiences a magnetic force of 0.15 N. Find the magnitude of the earth's magnetic field at the location of the wire, assuming the field

    asked by Anonymous on April 1, 2013
  84. Physics

    On earth, two parts of a space probe weigh 14500 N and 6400 N. These parts are separated by a center-to-center distance of 19 m and may be treated as uniform spherical objects. Find the magnitude of the gravitational force that each part exerts on the

    asked by Melanie on January 29, 2016
  85. history

    1. How did president John F. Kennedy most support civil rights? a. He favored voting rights laws ** b. He organized a march c. He established the peace corps d. He rode “freedom buses” 2. Which of the following was a result of the civil rights act of

    asked by abstract on May 2, 2016
  86. Physical Science

    The atom number of an element is the same as its.....protons, neutrons, or nucleons? same at the protons, same as the electrons Since this is not my area of expertise, I searched Google under the key words "atomic number" to get these possible sources:

    asked by Gina on March 29, 2007
  87. physics

    A 120 N child is in a swing that is attached to ropes 2.20 m long. Find the gravitational potential energy of the child-Earth system relative to the child's lowest position at the following times. (a) when the ropes are horizontal (b) when the ropes make a

    asked by Katie on October 18, 2010
  88. social studies

    how did spain establish territorial claims in the caribbean and south america?

    asked by yakelin on September 23, 2008
  89. faculty of science

    what nursing system are found in the south african health care

    asked by maty on April 25, 2010
  90. history

    what is an argument that the slaves from south carolina would support with the radifiacation of the constitution?

    asked by Anonymous on July 5, 2011
  91. life sciences business studies geography maths lit

    What are three challenges which most multinational corporations in South Africa is facing today

    asked by Bokamoso Lebeloane on June 3, 2017
  92. Science 5th

    If the speed of a car traveling south is increasing 5 m/s every second, its acceleration is__________.

    asked by Carol on October 21, 2009
  93. life orientation

    name 2 institutions in south africa that are involved in supporting water pollution

    asked by mpilo on April 29, 2013
  94. swo wg

    what is the city, located on the Conagree River, that is the capital of south carolina?

    asked by manuelR on January 8, 2009
  95. History

    List details of the current political situation in South Africa

    asked by Sue on February 16, 2008
  96. social studies

    what impact did the education improvement act of 1984 have on south carolina

    asked by ciara on May 12, 2015
  97. geography

    what are some of the advantages and disadvantages of south america's and europe's physical geography?

    asked by hannah mack on January 15, 2012
  98. life oriantation

    Name snd give an example of 4 types of media commonly used in south africa

    asked by thembelihle on March 30, 2016
  99. economics

    has tourism relieved poverty in south africa.give two reason

    asked by neo on September 6, 2018
  100. social studies

    what forms the border between south asia and the rest of the asian continent

    asked by anonymous on January 7, 2010