Two electrons are placed; one at north pole and other at south pole of earth. Find the force between them. Given diameter of earth= 12800 km.
225,384 results, page 65

Math
A 12 foothigh pole casts a 9 foot long shadow, at the same time of day, what would be the length of a shadow cast by a 45 footlong tree 
Math 7
how high is a tree that casts a 25 foot shadow at the same time a 6 foot pole casts a 10 foot shadow? Please help! I don't understand how to solve any problem like this!! 
Science
.a sodium atom has the following distribution of electrons in its energy cells: shell1: 2 electrons shell2: 8 electrons shell3: 1 electron I think its shell 2 
science
. How does the principle of uniformitarianism accounts for occasional catastrophic events such as meteorite impacts, huge volcanic eruptions, or great earthquakes? In what ways do geologic processes affect a person's daily life? . When astronauts brought back rock samples from... 
Physics
This is a twodimensional kinematics question: A particle's position coordinates (x,y) are (2m, 3m) at t=0; (6m, 7m) at t=2s, and (13m, 14m) at t=5s. Find the average velocity vector between t=0s and a) t=2s, b) t=5s. I don't know how to find this without acceleration being ... 
algebra
A can of soda at 79°F is placed in a refrigerator that maintains a constant temperature of 36°F. The temperature T of the soda t minutes after it is placed in the refrigerator is given by T(t) = 36 + 43e−0.058t. (a) Find the temperature, to the nearest degree, of the ... 
Math
A lorry travels at 50km/h. Given that the diameter of its wheel is 88cm, find how many revolutions per minute the wheel is turning. Given your answer to the nearest whole number. 
physics
Two forces 5N &10N are acting at an angle of 120° between them. Find the resultant force in magnitude and direction. 
Science
Two forces of 20 N and 5 N are acting at an angle of 120 degree between them. Find the resultant force in magnitude and direction ? 
electric engineering
An aircraft has a wing span of 56 m. It is flying horizontally at a speed of 900 km/hr and the vertical component of earth’s magnetic field is 0.4 m Wb/m2. Calculate the P.D between the wing tips of the air craft 
physics
A pulley with diameter D = 27in weighs 80 lb. It is mounted on a diameter d = 2in axle. A weight of 1000 lb is to be lifted. If the coefficient of friction f = 0.1, what vertical pull force P will be needed? 
Physics
A plumb bob does not hang exactly along a line directed to the center of the Earth's rotation. How much does the plumb bob deviate from a radial line at 38.5° north latitude? I got my answer to be 0.122288439 deg but it was incorrect. I used theta= a(sin 38.5)/g (which ... 
Math
The distance between two numbers on the number line is 19. One of the numbers is 8. What are the two possibilities for the other number? A.27 and 11 B.11 and 8 C.11 and 27 D.8 and 19 22.Which integer has the greatest absolute value? A.9 B.0 C.13 D.8 C 
History
3.How did Christianity help enslaved people resist? A.It taught them how to read and write B.It taught them the values of following rules C.It taught them that the wealthy were usually kind. D.It taught them that bad circumstances could be overcome. 4.How did the election of ... 
Science Earths Evolution
Tell me what you think plz 1.The Reason why it was not a solid planet yet is because Rocks or asteroids were still being formed. All there was were Dust and Tiny Particles were forming the asteroids. This was probably in the Hadean Era Because it was long ago, That’s ... 
physics
Two artificial satellites, 1 and 2, orbit the Earth in circular orbits having radii R1 and R2. If R2=2R1, the accelerations a2 and a1 of the satellites are related how? 
Linear algebra
In a medical prognosis model, there are three states for a person: well, ill and dead. We are given that the prob. one states well given that the person is well is 0.3. The prob. one becomes ill given that one is well is 0.5. The prob. one states ill given that one is ill is 0... 
Physics
A spring has a force constant of 100N/m and an unstretched lenght of .07 m. One end is attached to a post that is free to rotate in the center of a smooth table. The other end is attatched to a 1 kg disc moving in uniform circular motion on the table, which stretches the ... 
maths
A heavy 9cm diameter ball is placed in an empty cylindrical tin of diameter 12cm. Enough water is poured into the can to cover the ball.if the ball is then removed , how far does the water level fall 
maths
A heavy 9cm diameter ball is placed in an empty cylindrical tin of diameter 12cm. Enough water is poured into the can to cover the ball.if the ball is then removed , how far does the water level fall 
Science
1. How did planetesmals form planets? A. They broke apart into smaller chunks. B. They collided and stuck together.<<(I think it's this answer) C. They cooled and pulled ice together. D. They began to rotate. 2. What distance was used to define the astronomical unit (AU... 
Language Arts
I think that I shall never see A poem lovely as a tree. A tree whose hungry mouth is prest Against the earth’s sweet flowing breast; A tree that looks at God all day, And lifts her leafy arms to pray; A tree that may in summer wear A nest of robins in her hair; Upon whose ... 
Physics
As Alan is taking a shower, the soap falls out of the dish and Alan steps on it with a force of 500 N. If Alan slides forward and the frictional force between the soap and the tub is 50 N, what is the coefficient of friction between these two surfaces? 
Physics
As Alan is taking a shower, the soap falls out of the dish and Alan steps on it with a force of 500 N. If Alan slides forward and the frictional force between the soap and the tub is 50 N, what is the coefficient of friction between these two surfaces? 
Physics
As Alan is taking a shower, the soap falls out of the dish and Alan steps on it with a force of 500 N. If Alan slides forward and the frictional force between the soap and the tub is 50 N, what is the coefficient of friction between these two surfaces? 
Precalc(attn Bobpursley)
Hi i posted this before but I wanted to ask Bobpursley a few questions on his reply 1)For the first function you used cosine when they ask for sin, why is that? Also why did you put .5 in the beginning and end of the function? 2)For the second question why did you put 10 in ... 
english 9
Read the conclusion about “The Beginnings of the Maasai,” and then answer the question. One purpose of “The Beginnings of the Maasai” is to explain the weather. Which excerpt best justifies this conclusion? The sky god is powerful, but can change from nurturing to ... 
history
how were the south and the north the same? 
Physics
1. A test charge of +2x10^7 C is located 5 cm to the right of a charge of +1x10^6 C and 10 cm to the left of a charge of 1x10^6 C. The three charges lie on a straight line. Find the force on the test charge? 2. A charge of 2x10^9 C in an electric field between two metal ... 
Chemistry
I need chemistry help. I think 1. c, 2.b, & 3.a (please tell me why or why not and help me set up the problems if possible) 1.) The following half reaction has been balanced except for the electrons. How many and where should the electrons be included? 14 H+(aq) + Cr2O72(aq... 
physical science
plse make sure these are correct 1.When an atom loses an electron is.. a. becomes a negative ion. b. becomes a positive ion. c. forms a covalent bond. d. gains protons is the answer D 2.Which of these is a property of an ionic compound? a. low melting point b. poor conductor ... 
Social Studies
Which key figure in Christianity does this image represent? It is a picture of Jesus tided to a cross A. Peter B. Paul C. Jesus < D. God I know that it is Jesus but he never died on a cross, he died on a pole. 
english
My teacher told me that this sentence is ambigious. Can someone help me to fix this. "One of the main impacts is the transmission of many infectious diseases carried by insects, such as malaria and dengue which are sensitive to temperature, humidity, and changes in forest ... 
Physics
Suppose the surface (radius = r) of the space station in the figure is rotating at 38.6 m/s. What must be the value of r for the astronauts to weigh onehalf of their earthweight? 
Physics
Suppose the surface (radius = r) of the space station in the figure is rotating at 38.6 m/s. What must be the value of r for the astronauts to weigh onehalf of their earthweight? 
Physics
Suppose the surface (radius = r) of the space station in the figure is rotating at 38.6 m/s. What must be the value of r for the astronauts to weigh onehalf of their earthweight? 
physics
In a certain binary star system, each star has the same mass as our sun, and they revolve about their center of mass. The distance between them is the same as the distance between the EArth and sun. Wha tis their period of revolution in years? 
Physics  Momentum of cars at intersection
Two cars of identical mass are approaching the same intersection, one from the south and the one from the west. They reach the intersection at the same time and collide. The cars lock together and move away at an angle of 22deg counterclockwise from the road; heading east. ... 
Physics
A satellite has a mass of 99 kg and is located at 1.97 106 m above the surface of Earth. (a) What is the potential energy associated with the satellite at this location? Answer in J (b) What is the magnitude of the gravitational force on the satellite? Answer in N 
Physics 1
Two small particles of mass 16 kg and 27 kg are a distance 1.4 m apart. What is the gravitational force of one of these particles on the other?_____N 
physics
While two forces act on it, a particle is to move at the constant velocity = (3.99 m/s)  (3.19 m/s). One of the forces is 1 = (1.32 N) + (5.76 N). What is the other force? 
Calculus
Two ships are leaving port at the same time. The first ship is sailing due east at 20 km/hr and the other due north at 15 km/hr. How fast are the ships moving away from each other 2.0 hr later? 
10th grade
i have an equation; x^2+3x18=0. i am given one of the roots, of which is 3, but how do i find the other root. 
Math
1. 1. A police cruiser approaching a rightangled intersection from the north, is chasing a speeding car that has turned the corner and is now moving due east. When the cruiser is 0:6 miles north of the intersection and the car is 0:8 miles to the east, the police determine ... 
physics
Two girls each weight 500 N. Ride in a car traveling at 20.0 m/s. One wears a seat belt. The other does not. In an accident the girl wearing the seat belt is brought to a stop in 0.120 seconds. The dashboard brings the other one to a stop in only 0.00800 seconds. What is the ... 
Physics
We want to ﬁnd how much charge is on the electrons in a nickel coin. Follow this method. A nickel coin has a mass of about 4.9 g. Find the number of atoms in a nickel coin. Each mole (6.02 × 10 23 atoms) has a mass of about 58.1 g. Answer in units of atoms Find the ... 
Physics
A duck has a mass of 2.3 kg. As the duck paddles, a force of 0.08 N acts on it in a direction due east. In addition, the current of the water exerts a force of 0.21 N in a direction of 55° south of east. When these forces begin to act, the velocity of the duck is 0.10 m/s in ... 
Math
A oneminute advertisement on a local television station during prime time (810 p.m. on weeknights) costs the advertiser $12800. To the nearest cent, how much does the advertisement cost per second? I converted the minute to 60sec. Then divided the cost by the 60 and got $213... 
social studies
Who wrote the Virgin Islands national anthem Anastasia, have you done a google search on the Virgin Islands to find the answers to your questions? You might start there first. yes i did but i didn't find what i neededto find Ok, here's what I found for the Wikipedia entry for... 
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. 
Physics
The moon is 384,000 km from the earth and makes 1 revolution in 27.3 days. Find its angular and linear speeds in its orbit. 
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. 
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. 
maths
If two planes leave the same airport at 1:00 PM, how many miles apart will they be at 3:00 PM if one travels directly north at 150 mph and the other travels directly west at 200 mph? ( please help me with the working thanks ) 
physics
Two workers are moving a slab of ice (m = 290 kg) across the factory floor. As seen from above, one worker exerts a force of 415 N at an angle of 20o, and the other exerts a force of 470 N at an angle of 50o. What is the magnitude of the acceleration of the ice slab? 
calculus
A cooling tower for a nuclear reactor is to be constructed in the shape of a hyperboloid of one sheet. The diameter at the base is 260 m and the minimum diameter, 500 m above the base, is 200 m. Find an equation for the tower. (Assume the center is at the origin with axis the ... 
calculus
A cooling tower for a nuclear reactor is to be constructed in the shape of a hyperboloid of one sheet. The diameter at the base is 260 m and the minimum diameter, 500 m above the base, is 200 m. Find an equation for the tower. (Assume the center is at the origin with axis the ... 
physics
A boxcar of mass 3.21 x 10^4 kg is rolling south at 5.16 m/s when it collides and couples with another boxcar of mass 5.18 x 10^4 kg that is rolling north at 2.38 m/s. What is the velocity of the coupled boxcars after collision? Take north as positive and express your result ... 
science
I really need help with science and this is the questin reason for blank because earth is titled 23 1/2 from a line perpendicular to it's orbit,the legth of daylight varies and because of the angle at which the sun's energy strikes a given location through the year. 
PHYSICS
1. The problem statement, all variables and given/known data A ride in an amusement park consists of a cylindrical chamber that rotates around a vertical axis as shown in the diagram below. When the angular velocity is sufficiently high, a person leaning against the wall can ... 
Chemistry
True or False: The diameter of most atoms will be between 0.05 nm and 0.3 nm. I think its false (I don't think there even is an average diameter for atoms...), but I can't find any reliable sources to back up my hunch. Help please... 
Electrochemistry
A current of 2.50 A is passed through a solution containing Cu+2 ions for 4.00 hours. Calculate the mass of Cu atoms that form at the cathode. Charge= current*time Convert the charge in coulombs to number of electrons. Since it takes two electrons per Cu+2 atom, divide the ... 
Chemistry please check
1. Which of the following would occur as saturated hydrocarbons? alkanes alkenes alkynes cycloalkynes ans: alkanes 2. There are millions of organic compounds but only thousands of inorganic compounds because atoms of elements other than carbon never combine with themselves ... 
earh science
earths early atmosphere formed during the archean era. Which gas was generally absent from the atmosphere at this time http://en.wikipedia.org/wiki/Earth's_atmosphere#Evolution_of_the_Earth.27s_atmosphere 
Physics
A ferry is crossing a river.The ferry is headed due north with a speed of 2.5 m/s relative to the water and the river's velocity is 2.0 m/s to the east. What is the magnitude and direction of the ferry's velocity relative to Earth. ( Give the angle from east 0 degrees ) 
Geometry
I have two post that meet the ground perpendicular and the ground is level. One post is 40 feet high, the other is 25 feet high. If I draw a hypotenuse from the top of one post to the base of the other post and another hypotenuse from the top of the other post to the base of ... 
Goegraphy
What is the distance on the ground between two places that are 7cm apart on the south africa 
physics 213
A duck has a mass of 2.80 kg. As the duck paddles, a force of 0.120 N acts on it in a direction due east. In addition, the current of the water exerts a force of 0.190 N in a direction of 48.0 ° south of east. When these forces begin to act, the velocity of the duck is 0.120 ... 
Calculus
Ian's house is located 20km north of Aida's house. At 9am, one saturday, Ian leaves his house and jogs south at 8km/hour. At the same time Aida leaves her house and jogs east at 6km/h. When are Ian and Aida closest together given that they both run for 2.5 hours? The answer is... 
physics
two men decide to use their cars to pull a truck stuck in mud. They attach ropes and one pulls with a force of 688 N at an angle of 28° with respect to the direction in which the truck is headed, while the other car pulls with a force of 896 N at an angle of 20° with respect... 
physics
A river flows due east at 1.91m/s.A boat crosses the river from the south shore to the north shore by maintaining a constant velocity of 10.3m/s due north relative to the water. A.What is the velocity of the boat relative to shore? How far downstream has the boat moved by the ... 
Math
Mr. Oakley, my wood shop teachger is kind of strange. He has a 12 inch strip of wood with only four marks in it that he uses as a ruler. Yesterday, I asked him about it. "What good is a ruler you use uf ut only has 4 marks on it? There are some lengths you can't measure!" "... 
Algebra 1
1) Find the possible values of a, if the distance between the points is 5, and the coordinates are (1, 1) and (4, a). I don't know how to solve this one. 2) in a right triangle the length of the hypotenuse is 14 and the length b of one of the legs is 8. find the length a of ... 
algebra
given two containers, one holding 4 gal. and the other holding 3 gal. how does one measure out two gal.? Fill the 3 gal, pour it in the 4 gal. Fill the 3 gal, then pout it int the 4 gal until filled. How much is left in the 3 gal? thank you bobpursley!!!!!!!!!!! 
Physics
A car moves with a speed v on a horizontal circular highway turn of radius is R = 100. Assume the height of the car’s center of mass above the ground is h = 1 m, and the separation between its inner and outer wheels (car's width) is w = 2 m. The car does not skid (static ... 
science
what is the number of cycles an oscillator completes in one second is known? what is a force that always acts to pull a system back toward its equilibrium position? what is the distance from one point on a wave to the same point in the next cycle of the wave called? what is ... 
Physics
A 2 cm object is placed 42 cm from a screen. Where should a converging lens of focal length 7 cm be placed between them to form a clear image on the screen? What two possible magnifications could the image have?  1/do... 
geography
Compare and contrast folded mountains to volcanic mountains. How they are alike? How they are different? i got some of it.. Similarities: Both were probably formed from convergent plate boundaries. Difference: Volcanic Mountains  are mountains that form when molten rock ... 
Calculus
two small planes take off from the same airport at the same time. One travels north at 200 km/h, and the other, west at 150 km/h. If the planes fly at the same altitude, how fast are they separating after 2 hours? 
Calculus
two small planes take off from the same airport at the same time. One travels north at 200 km/h, and the other, west at 150 km/h. If the planes fly at the same altitude, how fast are they separating after 2 hours? 
science
An astronaut who weighed 170 pounds on Earth found that his weight on Jupiter was 400 pounds. He captured an alien that weighed 120 pounds on Jupiter. What is the alien's weight on Earth? A. 34 pounds B. 51 pounds C. 78 pounds D. 283 pounds 
astronomy
what distance do earth move in a second, a hour, a day? if the distance between eath and the sun is 150,000,000 km 
English 9
Ok, I really need help!! In my english class, we are supposed to find two examples of onomatopoeia in the poem "Porphyria's Lover" by Robert Browning. I can only find one!! Any ideas, anyone?? Thanks! Murmuring? thanks, but that's the one that i already found! Any other ideas... 
Sci Plzz See This Post
Does my poem below have these things "explain why it is where it is on the periodic table, what element(s) it might combine with to make a compound/molecule, and finally, WHY it would interact with that other element" Here is the Poem Below: “What’s your element my name... 
physics
Assumed that north is the ydirection and east the xdirection. You are piloting the boat that moves at a constant speed of 10 km/hr relative to the water beneath it. 1) On a body of still water, you point your boat due north for 2hr, then turn due east and continue for ... 
Geometry
Which statement is true? A. The altitude drawn to the leg of a right triangle forms two triangles that are similar to each other and to the given triangle. B. The altitude drawn to the hypotenuse of a right triangle forms two triangles that are similar to each other and to the... 
Geometry
Which statement is true? A. The altitude drawn to the leg of a right triangle forms two triangles that are similar to each other and to the given triangle. B. The altitude drawn to the hypotenuse of a right triangle forms two triangles that are similar to each other and to the... 
World History
Which statement supports the claim that the political philosophy of John Locke was as revolutionary as the scientific revolution of Copernicus? *****a. Just as Copernicus replaced the Earth with the Sun at the center of the solar system, Locke replaced the individual with the ... 
Physics
Two objects attract each other gravitionally with a force of 2.5 *10^10 N when they are .25m apart. Their total mass is 4.0kg. Find their individual masses. 
English 10
1. In the Aztec creation story, after the gods create Earth, how do the other gods feel about the new creation? A thrilled B ashamed C angry D excited *** 
Physics/Astronomy
What would a person's weight be on Mars compared to one's weight on Earth? 
Physics~
The moon's gravity is onesixth that of the earth. What is the period of a 0.25 m long pendulum on the moon? 
Science
Does the tilt of the earth cause one hemisphere to be closer to the sun? True or false False. 
PhysicsE&M
8.1 Collision? A permanent magnet creates a homogenous magnetic field B~ inside a rectangular region. The magnet is moving with a velocity ~v ⊥ B~ . A particle at rest with mass m and charge Q is on the path of the magnet. Assume that the magnet has a mass much larger ... 
Chemistry
Which atom has the smallest valence p atomic orbital? Carbon Nitrogen Sulfur Why? A. That atom has the highest electronegativity. B. That atom has the fewest number of electrons. C. That atom does not have electrons in p orbitals. D. The valence electrons for that atom have... 
math
building shadow 28 m long & the shadow cast by a 64 cm tall pole is 50 cm long. what is height of building? 
physics
A coin is placed on a vinyl stereo record that is making 33 1/3 revolutions per minute on a turntable. In what direction is the acceleration of the coin? Find the magnitude of the acceleration when the coin is placed 18 cm from the center of the record. What force accelerates ... 
Physics
The figure is just mass A on top of mass B. There are no forces or anything shown. Block A, of mass 3.2 kg, is on block B, of mass 7 kg, as shown in the above figure. The lower block is on a frictionless surface while the coefficient of static friction is 0.25 between the two ... 
social studies
what do th usa and korea have in common They are both democracies with high standards of living and healthy economies. Major industries of both countries are electronics, automaking and steel. I am refering to South Korea only. The US and South Korea ("Republic of Korea") ... 
Calculus
1.At noon of a certain day,ship A is ^0 km due north of ship B. If A sails east at 12 km/hr and B sails north 9 km/hr,determine how rapidly the distance between them is changing 2 hrs later. Is it increasing or decreasing? 2.At a given instant the legs of a right triangle are ...