1. Physics

    Q1: Find the frequency of revolution of the electron in the classical model of the hydrogen atom.In what region of the spectrum are electromagnetic waves of this frequency?? Q2:A beam of 13.o electrons is used to bombared gaseous hydrogen.What series of

    asked by Shah Rukh on June 3, 2014
  2. physics

    When two identical ions are separated by a distance of 4.0×10^−10 , the electrostatic force each exerts on the other is 5.7×10^−9 . How many electrons are missing from each ion? what i did was used coulombs law to find the value of q1 and q2 , so

    asked by Cassie on January 13, 2011
  3. PHYSICS II

    When two identical ions are separated by a distance of 4.0×10^−10 , the electrostatic force each exerts on the other is 5.7×10^−9 . How many electrons are missing from each ion? what i did was used coulombs law to find the value of q1 and q2 , so

    asked by Cassie on January 17, 2011
  4. PHYSICS II

    When two identical ions are separated by a distance of 4.0×10^−10 , the electrostatic force each exerts on the other is 5.7×10^−9 . How many electrons are missing from each ion? what i did was used coulombs law to find the value of q1 and q2 , so

    asked by Cassie on January 17, 2011
  5. physics

    A newly-discovered plant, "Cosmo", has a mass that is 4 times the mass of the Earth. The radius of the Earth is Re. The gravitational field strength at the surface of Cosmo is equal to that at the surface of the Earth if the radius of Cosmo is equal to...

    asked by Hannah on January 19, 2008
  6. physics

    A cricket ball travelling north at 100km/h is deflected so that it travels north-east at 100km/h. What is the change in velocity of the cricket ball?

    asked by Xy on March 12, 2017
  7. physics

    A cricket ball travelling north at 100km/h is deflected so that it travels north-east at 100km/h. What is the change in velocity of the cricket ball?

    asked by Xy on March 12, 2017
  8. university physics

    Two forces act on a 4.00-kg object in a manner that the object has an acceleration 3.00 m/s2 in a direction 20.0° north of east. The first force is 15.00 N in a direction 10.0° west of north. What is the second force?

    asked by mike on October 15, 2012
  9. maths

    a man goes 5m west and then 12m due south.Find the the distance of the man frm the starting point

    asked by faris on September 30, 2015
  10. MATHS

    A girl start at A and walks 2km south to B. she then walks 3km west to C. find the distance and bearing of C from A

    asked by MATHS on May 14, 2018
  11. Maths

    A geographical globe has a radius of 18cm.find the radius of the circleformed by the parallel of latitude 56 degrees south.

    asked by Tosin on November 20, 2012
  12. Maths

    A geographical globe has a radius of 18cm.find the radius of the circleformed by the parallel of latitude 56 degrees south.

    asked by Tosin on November 19, 2012
  13. social studies

    I need help checking my answers. the ! stands for my answer. 1. what three-day battle became the turing point of the civil war? gettysburg antietam greenville ! chancellorsville 2. the northern victory at_________ split the confederacy and gave control of

    asked by lila on February 11, 2015
  14. US History

    7. Which of the following was an advantage the North had over the South? a. more experienced generals b. military support from Britain c. more money to spend on war d. full support of all its citizens C? 8. In their Reconstruction, policies, both President

    asked by mysterychicken on October 13, 2010
  15. physics

    Jupiter's gravitational field at the surface is approximately three times that of the earth. A person weighing 120 lb. on the earth's surface would weigh how much on Jupiter?

    asked by Leo on June 17, 2012
  16. physic

    How long will a radio wave, with a wave length of 200 m takes to travel to and for the moon from the earth? (Distance of moon from earth = 3.9 x 108 m)

    asked by yumina on March 27, 2011
  17. physics

    the earth and moon has same type of and equal magnitude of charges to balance the gravitational force between earth and moon the required magnitude of charge will be

    asked by mann on November 29, 2017
  18. Physics

    Calculate the speed of a satellite moving in a circular orbit about the Earth at a height of 2700×10^3 m. The mass of the Earth is 5.98×10^24 kg and the mass of the satellite is 1400 kg.

    asked by Cameron on October 4, 2018
  19. Chemistry 101

    The distance from the Earth to the sun is approximately 9.37 x 10^7 miles. How long does ti take for light from the sun to reach the earth? Speed of light is 3.00 x 10^8 m/s. Show work.

    asked by Lilly on January 19, 2016
  20. physics

    Calculate the force of gravity between Earth (mass = 6.0 * 1024 kg ) and the moon (mass = 7.4 * 1022 kg) the average earth-moon distance is 3.8 * x10^8 m

    asked by Kareem on January 14, 2015
  21. physics

    calculate the force of gravity between earth (mass = 6.0 x 1024kg) and the moon (mass = 7.4 x 1022 kg). the average Earth-moon distance is 3.8 x 108 m.

    asked by marie on February 1, 2012
  22. Engineering Physics

    At a location 4Re away from the center of the Earth, you release a 2kg object from rest. How fast is the object traveling when it is 2Re away from the center of the Earth? Re = 6.4 x 10^6 m Me = 6 * 10^24 m

    asked by John on July 2, 2012
  23. physics

    A satellite orbits at a distance from the Earth's center of about 4.40 Earth radii and takes 13.0 hours to go around once. What distance (in meters) does the satellite travel in one day?

    asked by brett on February 4, 2012
  24. science

    how many days would it take to drive from the earth to the moon at a speed of 75 miles per hour? the average distance from the earth to the moon is 380,000km. 1 km=0.62 miles

    asked by emma on October 3, 2012
  25. Science

    The force of gravity of objects on the moon is approximately one-sixth of their value on Earth. Joe weighs 7633 N on earth. What will Joe's mass on the moon be?

    asked by Jessica on February 10, 2017
  26. Physics

    determine the point of zero gravitation force, as measured from the centre of earth (mass 5.97 x 10^24 kg) to the sun ( mass 1.99 x 10^30 kg) if the earth-sun distance is 150 x 10^6 km.

    asked by S on February 13, 2016
  27. Science

    The force of gravity of objects on the moon is approximately one-sixth of their value on Earth. Joe's weight on the moon is 124 N. What will Joe's mass on Earth be?

    asked by Jessica on February 10, 2017
  28. physics

    The earth exerts a downward force of 850 N on a veteran astronaut as he works outside the space shuttle. What force (if any) does the astronaut exert on the earth?

    asked by olga on February 10, 2011
  29. Social Studies

    Drag and drop the characteristics to the correct European nation. Characteristics may be used more than once. sugar was the valuable export added to claimed the east coast of South America conquered Peru imported enslaved Africans sugar was the valuable

    asked by dori on December 16, 2018
  30. physics

    Object A is moving due east, while object B is moving due north. They collide and stick together in a completely inelastic collision. Momentum is conserved. Object A has a mass of mA = 17.5 kg and an initial velocity of = 8.50 m/s, due east. Object B,

    asked by Ray on October 10, 2013
  31. Physics

    Object A is moving due east, while object B is moving due north. They collide and stick together in a completely inelastic collision. Momentum is conserved. Object A has a mass of mA = 17.9 kg and an initial velocity of = 8.82 m/s, due east. Object B,

    asked by Tim on November 4, 2012
  32. physics

    On a distant planet, golf is just as popular as it is on earth. A golfer tees off and drives the ball 3.7 times as far as he would have on earth, given the same initial velocities on both planets. The ball is launched at a speed of 44 m/s at an angle of

    asked by Dyer on February 10, 2011
  33. trig

    Since its construction in 1821, Marblehead Lighthouse has stood at the entrance to Sandusky Bay, guiding sailors along Lake Erie’s rocky shores. The 65-foot tower is one of Ohio’s best-known landmarks and the oldest continuously operating lighthouse on

    asked by Taylor on October 27, 2011
  34. english help!!?!?

    Mom smiles sweet as cold cash at each salesman in the carpet & dapery store where they offer my sister & me white mints fat as mushrooms while we walk up and down the aisles trying to make earth match the sky. What does the narrator mean when she says

    asked by robert on December 26, 2006
  35. SS

    1) How was South Carolina constitution of 1868 different from previous state constitutions? A. Women lost their right to own property. B. Representation was based on population alone. **** C. Countries and districts were organized into parishes.

    asked by Bella (pplease check!) on March 3, 2016
  36. Social Studies

    1) How was South Carolina constitution of 1868 different from previous state constitutions? A. Women lost their right to own property. ** B. Representation was based on population alone. C. Countries and districts were organized into parishes. D.Education

    asked by Ann on March 1, 2016
  37. maths

    from a point R,300m north of P,a man walks east wards to a place Q which is 600m from P find the bearing oF P from Q,correct to the nearest degree and the distance between R and Q.

    asked by Ijeh Evans on June 7, 2015
  38. history

    i found most of the info. on foot binding but still am unsure about a couple. was this mainly practiced in the sung dynast in the north???? Also i could not find what particular group of people engaged in this practice??

    asked by abby on September 17, 2008
  39. chemistry/physics

    i need to determine how many protons, neutrons, and electrons are in these but they arent just straight elements tehy are singly ionized hydrogen (positive) doubly ionized hydrogen(positive) and singly ionized oxygen (negative) these are my answers,

    asked by Andre on September 13, 2009
  40. Physics

    A neutral ball is suspended by a string. A positively charged insulating rod is placed near the ball, which is observed to be attracted to the rod. Why is this? 1. The ball becomes negatively charged by induction. 2. The string is not a perfect conductor.

    asked by Lynn on July 23, 2013
  41. Science

    Some of the mitochondrial electron transport carriers (the cytochromes) absorb light at characteristic wavelengths when they are carrying the extra electrons from NADH but not when they give up the electrons to the next carrier. Thus, the light absorption

    asked by Kyle on October 23, 2018
  42. English

    Canoe-trip by Douglas LePan i not know what be 3 powerful pictures in this. What of this fabulous country Now that we have it reduced to a few hot hours And sun-burn on our backs? On this south side the countles archipelagoes, The slipway where titans sent

    asked by Mohammad on May 31, 2012
  43. HISTORY HELP plsssssssss

    Use this map to answer the following question: This image shows a map of South America. The western coast is shaded blue. There are four numbers marking different areas on the coast. The first number marks an area at the very top of the shaded area. The

    asked by Oscar on April 18, 2016
  44. science

    list three differences between ions and isotopes? An ion is an atom that has at least one fewer electrons than it has protons. Thus, an ion always has positive charge. Hydrogen usually has one proton and one electron and has neutral charge. The hydrogen

    asked by airelle on December 3, 2006
  45. English Language

    How could I improve this piece of creative writing in order to get 20 out of 20. At the moment it is 15 out of 20. So when will you come? It was always my dream to become a fireman and today that dream came true. Now a member of the 117th New York

    asked by Hifza Faisal on January 29, 2016
  46. physics 1

    A boat has a cannon on board that faces aft. The boat is capable of traveling at 19 m/s on still water. The boat is traveling North on a river that has a current flowing south at a rate of 10 m/s. Following 20m directly behind the boat is a raft that is

    asked by john wiliams on November 23, 2017
  47. Physics

    A boat has a cannon on board that faces aft. The boat is capable of traveling at 19 m/s on still water. The boat is traveling North on a river that has a current flowing south at a rate of 10 m/s. Following 20m directly behind the boat is a raft that is

    asked by john wiliams on November 25, 2017
  48. AP Physics 1

    1. A delivery truck travels 21 blocks north, 16 blocks east, and 26 blocks south. What is its final displacement from the origin? Assume the blocks are equal length. 2. Vector V1 is 6.6 units long and points along the negative x axis. Vector V2 is 8.5

    asked by Vikram on January 15, 2016
  49. Chem.

    Using condensed electron configurations, give reactions showing the formation of the common ions of the following elements. (Type your answers in the following order. In the first box enter your answer using the format [Ar] 4s2 3d10 4p2 for [Ar]4s23d104p2.

    asked by Lucas on October 10, 2010
  50. physics

    Light is shining perpendicularly on the surface of the earth with an intensity of 680 W/m2. Assuming that all the photons in the light have the same wavelength (in vacuum) of 521 nm, determine the number of photons per second per square meter that reach

    asked by selu on May 6, 2015
  51. physics

    At what altitude above the Earth's surface is the acceleration due to gravity equal to g/128? i did g/128=(G*Earth's mass)/r^2 then solved for r and got 72080960. its within 10% of the correct answer but not correct. what am i doing wrong? (ive already

    asked by jawn on October 7, 2009
  52. Physics

    It takes Earth 365 days to complete one orbit around our sun. Knowing that the magnitude of the average acceleration the Earth experiences over half an orbit is 3.78 x 10^-3 m/s^2, what is the average speed with which it travels? Express your answer in

    asked by Alex on December 9, 2018
  53. Physics

    I'm not sure how to go about solving this problem the algebra gets very messy... At what distance formt he EArth will a spacecraft on the way to the Moon experiance zero net force due to there two bodies because the Earth and Moon pull with equal and

    asked by Jake on December 23, 2009
  54. Physics

    Help!! I would greatly appreciate help with this question. Consider a pulse of laser light aimed at the Moon that bounces back to Earth. The distance between Earth and the Moon is 3.84 * 108 m. Show that the round-trip time for the light is 2.56s.

    asked by Anne on December 4, 2014
  55. physics

    Light is shining perpendicularly on the surface of the earth with an intensity of 680 W/m2. Assuming that all the photons in the light have the same wavelength (in vacuum) of 478 nm, determine the number of photons per second per square meter that reach

    asked by PLEASE AND THANK YOU on April 6, 2013
  56. Physics please help

    Geosynchronous satellites orbit the Earth at an altitude of about 3.58×10^7 m. Given that the Earth's radius is 6.38×10^6 m and its mass is 5.97×10^24 kg, what is the magnitude of the gravitational acceleration at the altitude of one of these

    asked by Kevin on June 9, 2012
  57. PHYSICS

    Light is shining perpendicularly on the surface of the earth with an intensity of 680 W/m2. Assuming that all the photons in the light have the same wavelength (in vacuum) of 478 nm, determine the number of photons per second per square meter that reach

    asked by please help on April 4, 2013
  58. Math

    A satellite is launched into orbit 200 kilometers above the Earth.The orbital velocity of a satellite is given by the formula v=√GmE/r, where v is the velocity in meters per second, G is a given constant, mE is the mass of Earth, and r is the radius of

    asked by Macy on April 6, 2010
  59. Physics

    An air traffic controller observes two airplanes approaching the airport. The displacement from the control tower to plane 1 is given by the vector A , which has a magnitude of 220 km and points in a direction 32 degrees north of west. The displacement

    asked by Hiral on June 28, 2012
  60. us history

    What was the society of south circa 1840? I was doing some flash cards for us history and this was one of the vocab terms. I couldn't find anything about it in my textbook, notes, and met a similar difficulty while trying to look for it on the internet.

    asked by Chrys on November 25, 2012
  61. math

    If a satellite completes an orbit 820 miles above the earth in 11 hours at a velocity of 22,000 mph, how long would it take a satellite to complete an orbit if it is at 1400 miles above the earth at a velocity of 36,000 mph? (Use 36,000 miles as the radius

    asked by vera on August 4, 2012
  62. Geography

    I have this really hard puzzle that i need to solve for my class but I'm having a hard time. Can someone please help me? I've been given a list of places and a list of hints and I have to find out which place fits the hints that are given. The places are:

    asked by mysterychicken on August 26, 2009
  63. Social Studies

    7. Select one movement from the Progressive Era. Describe the movement and its impact reform on South Carolina. Provide details and examples that support how this movement changed South Carolina. I chose the civil right movement I just don't know how to

    asked by Alexis on April 12, 2016
  64. Physics for life scince

    The population of Singapore is 4987600 people. The territory of Singapore is 710.2 km^2. the population of South Africa is 2171000people, while its territtory is 824292. Estimate the population densities of Singapore and South Africa.

    asked by Simeon on March 23, 2010
  65. science

    Couple of questions. Why does the earth keep moving? The engine of a rocket applies a continual force to push the rocket along. When the engine stops what will happen? I think the rocket will stop acceleration You need to be aware of the concept of

    asked by Kim on May 8, 2007
  66. Algebra..please check my work!!

    At 3 p.m., Brunhilde headed north at 30 kilometers per hour. Two hours later Ludwig headed south at 40 kilometers per hour. At what time will they be 340 kilometers apart? I know that the distance from Brunhilde(Db) plus the distance from Ludwig(Dl) is

    asked by Tim on December 7, 2007
  67. math help

    on a drive through allegheny county, natalie drove due west for 9 miles, then turned left and proceeded to drive due south. after traveling 12 miles south, what was the straight line distance between where natalie started and where she ended her drive?

    asked by Anonymous on August 29, 2011
  68. physics

    Bob is sitting a subway train going south at speed of 2.50 m/s. Morgan is walking towards her down the center aisle of the train. To jen, standing on the platform, Morgan seems to be moving at a speed of 2.75 m/s to the south. How fast and in what

    asked by Khanh on February 2, 2015
  69. Chemistry

    Draw Bohr diagrams of the following: A) O and O2- I know how to draw the regular O bohr diagram. 2 electrons in the first shell, and 6 in the outer one, but I don't get how to draw a 02- diagram. Do I just take away 2 electrons from the outer shell?

    asked by Anonymous on September 18, 2010
  70. Physics

    A beam of protons is accelerated through a potential difference of 0.745 kV and then enters a uniform magnetic field traveling perpendicular to the field. (a) What magnitude of field is needed to bend these protons in a circular arc of diameter 1.75 m? (b)

    asked by J on February 25, 2008
  71. Math

    Two ships are moving toward a rendezvous point. Ship A is 5km east and 4km north of the point Ship B is 1km west and 2km north pf the point. How many km part are the two ships? Please . I really need your help

    asked by Niall on December 1, 2014
  72. physics

    vicky walks 8km east, the 5km south and final 6km west. find her final displacement

    asked by Vanne on June 23, 2013
  73. Physics

    forces of 185N and 245N act east and south respectively on an 80 kg mass.If the force of friction is ZERO , find the accleration of the mass.

    asked by Jo on December 9, 2010
  74. Business

    Where can I find info on doing business in south america. I have to write a paper on what coutry is best to do business in Cuba, Brazil, or Uraguay

    asked by Amanda on September 21, 2007
  75. Physics

    You walk 25 m south and 40 m east. Find the magnitude and direction of the resultant displacement both graphically and algebraically. Magnitude is 47.16 What is the degree?

    asked by HS Senior on October 1, 2018
  76. Pre-Calculus

    A 15N force acting at 15 degrees north of east and a 18N force acting at 79 degrees north of west act concurrently on an object. What is the magnitude and direction of a third force that produces equilibrium on the object? Show sketch and work. ------

    asked by Alexis on March 3, 2014
  77. INTRO TO PLANET EARTH

    ....Unit 2 Which type of eclipse would you expect to see if the moon passes directly between Earth and the Sun A. A solar Eclipse B. a lunar eclipse C. a total lunar eclipse D. a penumbra Which of the following happens during a lunar eclipse? A.a lunar

    asked by Chocalae Bonny on September 12, 2018
  78. Social studies

    Which of the following is an accurate comparison of Adams and Jackson A. Adam supported efforts to promote the group of businesses well Jackson supported efforts to help the ordinary man B. Jackson supported the idea of high tariffs to increase revenue but

    asked by Anything helps on November 28, 2017
  79. Physics equation?

    can anybody tell me an equation that can be used to find the number of electrons flowing through an LED every second? and also refer or give me any information that could explain another mechanism (apart from the fact that they denote energy to a single

    asked by AllyKat on February 11, 2008
  80. Physical Science

    The distance from earth to the sun is 1.5x10 to the 11th power minutes and light travels at a speed of 3.0x10 to the 8th power m/s. How long does it take sunlight to reach the earth? Give answer in minutes and seconds.

    asked by Belaune on January 21, 2013
  81. Physics

    The shuttle is orbiting the earth at a distance of 500km above the earths surface. Assumingan astronaut has a mass of 72kg, what is the force of gravity upon him or her? You may assume the earth has a mass of 5.98 x 10^24kg and a radius from the center to

    asked by Bianca on January 19, 2011
  82. physics

    The power output in the sun is about 4.00 x 10^26W. (a). Calculate the power per unit area (intensity), in kilowatts per square meter, reaching Earth's upper atmosphere from the sun. The radius of the Earth's orbit is 1.5 x 10^11m.

    asked by Anonymous on March 5, 2015
  83. Science

    A space probe on the surface of Mars sends a radio signal back to earth a distance of 8.66x0^7 km. Radio waves travel at the speed of light (3:00x10^8 m/s . How many seconds does it take the signal to reach earth

    asked by Sherri on January 21, 2016
  84. physics

    the rate at which radiant energy from the sun reaches the earth's upper atmosphere is about 1.50kW/m2. the distance from the earth to the sun is 1.50*10^11m, and the radius of the sun is 6.96 * 10^8m. if the sun radiates as an ideal black body (e=1), what

    asked by jean on May 7, 2017
  85. physics

    An artificial sattelite as a mars of 600 kg and moving towards moon.calculate its kinetic energy and potential energy in mJ relative to the earth when it is 50 km from launching and moving at 2500 km/h take acceleration of earth gravitational field as 790

    asked by vishal vegad on February 15, 2013
  86. Physics

    A skydiver is jumping from an airplane traveling at 10.0 m/s. The plane is 3520 m above the earth. The sky diver pulls his cord at 1760 m above the earth. Neglecting air resistance, how far does the skydiver travel horizontally before pulling the cord?

    asked by Isis on June 14, 2013
  87. biology

    What is the source of energy driving the hydrolic cycle? a. evaporation of the ocean water b. heat conducted from the earth's core to the surface c. radiant heat from the sun d. air currents returning to the earth's surface

    asked by BECKY on February 23, 2010
  88. science

    Look at the picture on the immediate left here: http://en.wikipedia.org/wiki/Earth's_magnetic_field Also: http://image.gsfc.nasa.gov/poetry/magnetism/magnetism.html HOW IS THE EARTH'S MAGTISM USEFUL thanks it helped me alot!!!!!!!!!!!

    asked by Lance on December 12, 2006
  89. algebra

    The weight of an object follows the equation w=Cr^-2, where C is the constant and r is the distance the object is from the center of the earth. a. solve the equation for r. b. Suppose the object is 100 pounds when at sea level. Find the value of C that

    asked by Carson on March 6, 2010
  90. college

    Find the minimum initial speed of a projectile in order for it to reach a height of 2039 km above the surface of the earth.

    asked by Anonymous on April 29, 2010
  91. Statics

    Two identical spheres of radius 80mm and mass 2 kg on the surface of the earth are placed in contact. Find the gravitational attraction between them.

    asked by Woz on April 19, 2013
  92. Physics

    Find the minimum initial speed of a projectile in order for it to reach a height of 2022 km above the surface of the earth.

    asked by Rebecca on November 12, 2015
  93. Physics 203

    An object is projected upward from the surface of the Earth with an initial speed of 4.6 km/s. Find the maximum height it reaches.

    asked by Kayla on April 26, 2011
  94. Physics

    An object weighs 100N on the earth's surface. Find its weight at a point P with orbital radius 2R. [g = 10NKg-1

    asked by Majiri on September 17, 2017
  95. Geography (Ms. Sue)

    Which countries besides Spain sent settlers to South America? A: Besides Spain, Portugal, France, and the Netherlands sent settlers to South America?

    asked by Anonymous on September 27, 2013
  96. physics

    An astronaut of mass 80 kg lands on a planet,the radius of which is half that of the earth and the mass of which is three times that of earth.what will be the force of attraction which this planet has on him?

    asked by natty on February 26, 2014
  97. Physics

    A canoe has a velocity of 0.400 southeast relative to the earth. The canoe is on a river that is flowing at 0.450 east relative to the earth.

    asked by Anonymous on August 13, 2012
  98. Science

    If the earth exerts a 500 N gravitational force on an object in near space, how much force does this object exert on the earth, and by what law can this be asserted?

    asked by Alyssa on May 18, 2016
  99. math

    The ratio of an object's weight on Earth to its weight on Neptune is 5 : 7. How much would a person who weighs 150 pounds on Earth weigh on Neptune?

    asked by mark on December 3, 2014
  100. Science

    Here is a question on my science worksheet, "if a projectile's fall matches Earth's 'BLANK', the projectile will not hit earth." i need help figuring out what would go in the blank!

    asked by Morgan on February 24, 2010