# Why must the centre of the satellite orbit coincide with the centre of the Earth?

25,143 results, page 45

### Physics

Suppose a single electron orbits about a nucleus containing two protons (+2e), as would be the case for a helium atom from which one of the two naturally occurring electrons is removed. The radius of the orbit is 2.65 10-11 m. Determine the magnitude of the electron's ...

### Physics

A 0.59g mass of Glynnium goes through a nuclear fission reaction. The energy from the process is used to lift a 97211kg Saturn 5 rocket into orbit. If the mass is transformed with 1% efficiency, what height does the rocket reach? Express your answer in kilometers

### physics

please check these 3: if the batteries in a portable CD player provide a terminal voltage of 12 V, what is the potential difference across the entire CD player? a. 3.0 V b. 4.0 V c. 6.0 V d. 12 V D two resistors having the same resistance value are wired in parallel. how does ...

### physics

Calculate the acceleration due to gravity on the moon. The moon\'s radius is about 1.74 E 6 m and its mass is 7.35 E 22 kg ok aparently there\'s an easier way to do this I applied Newtons second law in the radial direction net force radial = m (radial acceleration) = Fg were ...

### English

I left out the questionnaire I really need you to check. I have to refer to what happens in America. 1)You can get a part-time job when you are..You can ride a 50cc moped when you are......You can't leave school until you are......You must be ......to join the army. You must ...

### Physics

A canoe has a velocity of 0.480m/s southeast relative to the earth. The canoe is on a river that is flowing at 0.510m/s east relative to the earth. Find the magnitude of the velocity (V(C/R)) of the canoe relative to the river. Also, find the direction of the velocity of the ...

### US History

List 3 responsibilities that we have as American citizens? 1) Citizens must VOTE 2) Citizens must obey the laws 3) Citizens must________ i don't know what is the third one please help!!!!

### Math

Financial aid students must pass 2/3 of their courses each term in order to continue their aid. If a student is taking 18 hours, how many hours must be passed?

### Stat

If radio station call letters must begin with either K or W and must include either two or three additional letters, how many different possibilities are there?

### Stats

if a researcher were studying the effects of a teaching method on patient learning outcomes, how must he or she word the research question (different from hypothesis) to use the t-test for statistical differences? What type of data must he or she collect (interval, ratio, ...

### Physics

On the earth, you throw an object up in the air at some velocity, v, and it reaches a maximum vertical displacement (max. height if you prefer) of 4.8 meters. If you went to the moon, where the value of the gravitational acceleration of the moon is 1/6 of that on earth, and ...

### Economic

A Giffin good is not correctly described by which of the following? A)A Giffin good must be an inferior good. B)A Giffin good must be such that the income effect and the substitution effect move in opposite directions, and the income effect outweighs the substitution effect. C...

### Current/Magnetic force

A high voltage power line carries a current of 110 A at a location where the Earth's magnetic fields has a magnitude of 5.9 x 10^-4 T and points north at an angle of72 degrees below the horizontal (toward the earth surface). Find the direction and magnitude of the magnetic ...

### physics

A pulsar is a rapidly rotating neutron star that continuously emits a beam of radio waves in a searchlight manner. Each time the pulsar makes one revolution, the rotating beam sweeps across the earth, and the earth receives a pulse of radio waves. For one particular pulsar, ...

### Physics

A pulsar is a rapidly rotating neutron star that continuously emits a beam of radio waves in a searchlight manner. Each time the pulsar makes one revolution, the rotating beam sweeps across the earth, and the earth receives a pulse of radio waves. For one particular pulsar, ...

### 12 math

a library shelf contains 7 books. in how many ways can they be arranged if there are no restrictions? b. the mathamatics text book must be first. c.the 3 math text boooks must be together

### math

Certain financial aid students must pas 2/3 of the courses each term in order to continue their aid. if a student is taking 18 hours, how many hours must be passed?

### algebra

to pass a course with an A grade, a student ,must have an average of 90 or higher. A students grades on three tests are 93,92 and 83. What is the score the student must get on the nest test to get an A average?

### Chemistry

A home swimming pool contains 145 m3 of water. At the beginning of the swimming season, the water must be heated from 20 to 32°C. How many joules of heat energy must be supplied?

### Chemistry

A home swimming pool contains 145 m3 of water. At the beginning of the swimming season, the water must be heated from 20 to 32°C. How many joules of heat energy must be supplied?

### HELP GRAMMAR

if you say twenty days to respond and a few paragraphs later say the petition must be filed within 90 days is that correct or must both match

### Algebra 2

Make up an equation that satisfies the given conditions: must have x-intercepts at (1,0) and (2,0). It must also have a y-intercept at (0,4). How do you factor the y-intercept?

### statistics

Your best friend is 5 months pregnant and wants you to be there when the baby is born. Since the baby was conceived on Labor Day, the delivery might coincide with your annual trip to cabo. the doctor tells you that the gestation period for humans is normally distributed with a...

### Math

A year on Mars is 686 Earth Days. (1) Which is longer, a year on Mars or a year on Earth? (2)By how many weeks is it longer? Submit two answers. Please explain how you got the answers. My 1st answer was Mars the 2nd answer I 82 1/2 weeks. Please help

### algebra

5.A) Kwame sells ice cream cones at the country fair. He has to rent the equipment for $29 and spend $0.43 on ingredients for each cone. How many ice cream cones must he sell at $1.10 each in order to make a profit? A)Wrie an inequality that represents how many ice cream cones...

### Physics

An army of armadillios is attacking Cosine Castle where the coyotes reside. If an army must clear the 45 meter walls by 5 meters, at what angle must they set their cannons (from the horizontal) in order to fire inside the castle walls? The cannons fire cannonballs at 50 m/s. ...

### physics

Imagine a frictionless perfectly straight tunnel which runs from Boston (USA) to Delhi (India). We release (at zero speed) an object in the tunnel in Boston. Assume that the Earth is a perfect sphere with radius 6.4*10^3 km, with a mass of 6.0*10^24 kg and that the mass ...

### physics

Imagine a frictionless perfectly straight tunnel which runs from Boston (USA) to Delhi (India). We release (at zero speed) an object in the tunnel in Boston. Assume that the Earth is a perfect sphere with radius 6.4*10^3 km, with a mass of 6.0*10^24 kg and that the mass ...

### algebra

In Chemistry class, Andrew has earned scores of 64, 69, and 73 on three tests. He must maintain an average of 70 to pass the course. What score must Andrew earn on the final exam to pass the course?

### Math 221

where is the origin located in this equation? 1). The first equation that I am using for my discussion is: y=x+4 and the parallel must past through this given point (-7, 1) y=x=-4 is the equation and (-7, 1) is the ordered pair y=x+4 Since I want the new line parallel, I need ...

### Social Studies

One reason for the difference between average temperatures in Rome when in Jan. the average temperature is 11 degrees Celsius and July average degree is 30 degree Celsius is: The amount of carbon dioxide present in the atmosphere The tilt of the Earth of its axis The tidal ...

### English

1. The earth goes around the sun. 2. The eatth moves around the sun. 3. The earth goes round the sun. 4. The earth moves round the sun. (Which one do I have to use?) 5. Many boys were sitting around the lake. 6. Many boys were sitting round the lake. (Do I have to use 'round' ...

### PHYSICS

Compare the electric force holding the electron in orbit (r=0.53Ã—10âˆ’10m) around the proton nucleus of the hydrogen atom, with the gravitational force between the same electron and proton. What is the ratio of these two forces?

### SCIENCE

Determine the mass of a person on the moon whose mass on Earth is 70 kg Determine the weight of a person on the moon whose weight on Earth is 148 lbs. How is the mutual gravitational force affected by changing the separation distance between two 1.0 kg masses if the distance ...

### ALGEBRA

1. Many people know that the weight of an object varies on different planets, but did you know that the weight of an object on Earth also varies according to the elevation of the object? In particular, the weight of an object follows this equation: , where C is a constant, and...

### science

If a cement block that weighs 50 N must be raised to a height of 5 m, how much work must be done on the block? Work=weight*heightincreased

### math

Taking the speed of the radio signal as 3×108 m/s, calculate the time taken for a signal to reach a GPS receiver from a GPS satellite at a position 21 000 km distant from the receiver. Assume that the speed of the signal is unchanged over the whole path length. Express your ...

### Science

An engineer messed design a runway to accommodate airplanes that must reach a speed of 71 m/s before they can take off the planes are capable of accelerating at a rate of 1.6 m/s person per second the minimum length of the runway must be _______

### metreology

Wien’s radiation law says that the wavelength of most intense radiation (λmax) emitted by a blackbody is inversely proportional to the absolute temperature (T) of the object. The surface of the Sun radiates as a blackbodyat a temperature ofT=6000 kelvins so that the Sun...

### Physics HELP!!!!!!!!

The earth rotates once per day about an axis passing through the north and south poles, an axis that is perpendicular to the plane of the equator. Assuming the earth is a sphere with a radius of 6.38 106 m, determine the speed and centripetal acceleration of a person situated ...

### Physics

In its own frame the average pi meson lives 2.60 x 10^-8s. Suppose it moves at 0.985c relative to the Earth. According to us, on Earth, what is a pi meson's average lifetime? (b) according to us, what is the pi meson;s average travel distance before decaying? (c) If time ...

### Statistics

Find an example of application of Normal Distribution (or approximately Normal Distribution) in your workplace or business (or any other business that you are familiar with). Prove that the variable has the characteristics of a Normal Distribution. Recall that the variable ...

### physics

A bicyclist starts a timed race at 6 mph In order to win, he must average 21 mph Assuming constant acceleration from the start, how fast must he be traveling at the end of the race?

### Math

To pass a course with a C grade, a student must have an average of 70 or greater. A students grades on three tests are 63, 76, 67. Find what score the student must get on the next test to get a C average or better

### Physics180

Tidal forces can break apart objects that orbit too close to a planet, producing rings like those of Saturn. Consider an asteroid 600km in radius, 65mm from Saturn's center. What's the difference in gravitational acceleration between the two sides of the asteroid?

### Astronomy

In fact, more precise calculations suggest that ISON was on a hyperbolic, unbound orbit. How much more precise? Find the minimal speed with which the comet would have had to be moving when observed at perihelion in order to eventually escape the Solar system, in km/s.

### Physics

Calculate the work done by planet X on its moon. Planet X applies a force of 5.6 x 10^10 N on its moon and the moon is 4.0 x 10^8 km away from the planet and it continues to circle the planet in a circular orbit of circumference of 2.5 x 10^9 m.

### Chemistry - is this correct?

Write the electronic configuration for nickel(#28). I know it is 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^8 (b) How many electrons are there of highest energy in nickel? Is it 8? (c) how many electrons are there in the outermost energy level(orbit) of nickel? Is this 8 also?

### chemistry

The total surface area of earth is about 1.97*10^8 square miles. the surface area of land on earth is about 5.73*10^7 square miles. find the ratio of the surface area of land to the entire planet.?

### math

Eric is putting together alien toys called zerg and Borges for the display window in a toy store. He has a box of alien body parts that contains 45 heads and 55 feet. Each zerg must have one head and three feet.each Borg must have four heads and two feet. How many zergs and ...

### trig

L ii i i i i i i i i A i i i i i i i i i i 4000 miles i i i i E ii right triangle have to find side EL. The range of a lighthouse is the maximum distance at which its light is visible. In the figure, point A is the farthest point from which it is possible to see the light at ...

### 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 of the object on Earth...

### Physics

Which of the following involves a non-zero net force? I. A hockey-puck sliding at a constant speed on ice. II. The earth revolving around the sun at a constant speed. III. An object falling near the surface of the earth. A) I only B) III only C) Both I and II D) Both II and ...

### SCIENCE PLZZ HELP!!!

____ is rate of change of position. Speed Velocity Acceleration Displacement 2. Which of the following is the difference between speed and velocity? direction units speed none of the above 3. A planet is discovered that is the same size as Earth and has the same gravitational ...

### english grammar

I have learned what the most important basis skill for teamwork. For a successful teamwork, team members must have team conditions: clear goals, common responsibility, open communication, mutual respect and flexibility. Open communication and mutual respect is very import for ...

### math

in her chemistry class, Lauren must produce 300ml of an 80% acid solution. Her teacher gives her two concentrations of acid solution, a 50% and a 100%. determine how much of each concentration that she must use.

### Math Linear Inequalities

A rectangular enclosure must have an are of at least 4800yd^2. If 280yd of fencing is used, and the width can not exceed the length, within what limits must the width of the enclosure lie?

### physical science

John is using a pulley to lift the sail on his sailboat. The sail weighs 150 N, and he must lift it 4.0 m. A. How much work must be done on the sail? B. If the pulley is 50% efficient, how much work must John do on the rope to lift the sail?

### physics

Superman must stop a 120km/h train in 150m to keep it from hitting a stalled car on the tracks.If the train's mass is 3.6x10^5kg,how much force must he exert?Compare to the weight of the train (give as%).

### Science

Which of the rock-forming mineral groups makes up the largest group of minerals in the Earth's crust? Look here for your answer. http://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=minerals+earth%27s+crust&btnG=Search http://en.wikipedia.org/wiki/Silicate_minerals I don't Know

### Chemistry

About twenty radioisotopes with ultra-long half-lives, from 82 million years (244- Plutonium) to 6 million billion years (50-Vanadium) are found in the earth’s crust, yet no radioisotopes with half-lives less than 70 million years (146- Samarium) are found. Why not? Use this...

### algebra

Hint: Pay attention to the units of measure. You may have to convert from feet to miles several times in this assignment. You can use 1 mile = 5,280 feet for your conversions. 1. Many people know that the weight of an object varies on different planets, but did you know that ...

### algebra

Hint: Pay attention to the units of measure. You may have to convert from feet to miles several times in this assignment. You can use 1 mile = 5,280 feet for your conversions. 1. Many people know that the weight of an object varies on different planets, but did you know that ...

### college

Hint: Pay attention to the units of measure. You may have to convert from feet to miles several times in this assignment. You can use 1 mile = 5,280 feet for your conversions. 1. Many people know that the weight of an object varies on different planets, but did you know that ...

### Math

Hint: Pay attention to the units of measure. You may have to convert from feet to miles several times in this assignment. You can use 1 mile = 5,280 feet for your conversions. 1. Many people know that the weight of an object varies on different planets, but did you know that ...

### French Revolution

What are 5 foods from before the French Revolution (MUST reflect the ideas of the time) 5 foods from after French Revolution (MUST reflect the ideas of the time) 1 Dish or meal from each (2 total) must include ingrediants 2 foods that are popular right now that were influenced...

### Project Mangement

What sort of organization structure and culture enhances the prospect of a successful project outcome? Here are some lessons learned on Project Management: 1) Technical direction cannot be separate from cost and schedule decisions. The PM must be able to trade off technical, ...

### Math (inequalities)

1)Each packet must have at least 20 gold stars = x > or equal to 20 2)Each packet must have at least 15 silver stars = y > or equal to 15, is this correct? 3)The total number of stars in each packet must not be more than 60 = x+y < or equal to 60, is this correct? 4)x...

### algebra

The distance D , in miles to the horizon from an obsever's point of view over water or flat earth is given below , where H is the height of the point of view in feet . if a person whose eyes are 5ft above ground level is standing at the top of hill 45 ft above 'flat"earth, ...

### physics

A person is standing at the edge of the water and looking out at the ocean (see the drawing). The height of the person’s eyes above the water is h=1.6 m, and the radius of the earth is R=6.38x10^6 m (use as a precise value). (1) How far is it to the horizon (in meters, use ...

### Physics

An aluminum wire with mass/unit length of p = 5*10^-4 kg/m lies on the ground, running east-west. The wire feels the earth's magnetic field, which has magnitude B = 5*10^-5 T. Assume the wire is in Columbia, where the Earth's magnetic field runs due north, parallel to ground. ...

### AP LIT

A VALEDICTION FORBIDDING MOURNING by John Donne As virtuous men pass mildly away, And whisper to their souls to go, Whilst some of their sad friends do say, "Now his breath goes," and some say, "No." So let us melt, and make no noise, [5] No tear-floods, nor sigh-tempests move...

### Maths A

Select 48 values according to the following criteria. o The first thirty (30) numbers must lie in the range from 48 to 58 inclusive. o The next ten (10) numbers must lie in the range from 30 to 70 inclusive. o The remaining eight (8) numbers must lie in the range from 50 to 95...

### Physics/Astronomy

A pulsar is a stellar object that emits light in short bursts. Suppose a pulsar with a speed of 0.975c approaches Earth, and a rocket with a speed of 0.999c heads toward the pulsar (both speeds measured in Earth’s frame of reference). If the pulsar emits 20.0 pulses per ...

### Physics

(1) body is taken to depth of 32km below the surface of the earth. Calculate the percentage decrease in the weight of the body at this depth (The radius of the earth is 6400km) (2)A wire of mass per unit length 5.0gm-1 is stretched between 2 points 30cm apart. The tension in ...

### math

yank hardy pulls the cord on his power mower. in order for the engine to start, the pulley must turn at 180 revolutions per minute. the pulley has a radius of 0.2 ft. how many radians per second must the pulley turn? How fast must yank pull the cord to start the mower? when ...

### english

What is the one thing Countee Cullens finds to be God’s strangest “mistake”? a.)creating a black poet b.)making moles blind c.)that people must all die d.)that the Greek king Tantalus must be punished for all eternity

### Physics

How would a physics expert respond to the following suggestions made by three airline executives? Write a script of the expert's response for performance in front of the class. Airline Exectutive A: Since the earth rotates from west to east, we could operate 'static flights'--...

### Science-Earth's History

The geologic time scale originally ordered Earth's rocks by: A. absolute age B. relative age C. composition D. decades and centuries B Where did scientists originally get their information to develop the geologic time scale? A. They collected and studied rock samples in Europe...

### probobility

4 -letter "words" are formed using the letters A, B, C, D, E, F, G. How many such words are possible for each of the following conditions? (a) No condition is imposed. Your answer is : Preview (b) No letter can be repeated in a word. Your answer is : Preview (c) Each word must...

### physics

A 3Kg projectile is fired straight upward from earth's surface with a speed that is one-fourth the escape speed. Neglecting air resistance. a) What is the Kinetic energy of this projectile when it is launched? b) what is the gravitational potential energy of this projectile ...

### What must be added maths need help

What must be added to x/y to make it y/x??

### Science

1. The Hertzsprung-Russell diagram below shows how the brightness, surface temperature, and color of stars are related.stars would be * 3 points Captionless Image A Barnardâ€™s Star is less bright than the sun, has a surface temperature below 3,800 K, and is red. * B ...

### american government

The Privileges and Immunities Clause of the Fourteenth Amendment means (Points : 1) citizens of the United States may travel across state lines without documentation. states must all have the exact same laws as each other. that if one state recognizes gay marriage all states ...

### GEOGRAPHY / SCIENCE

The theory that addressed the apparent ability of landmasses to move through the crust is called Continental Drift? I think this is the answer but not sure. Please help Yes, You're right. The Continental Drift theory is based on plate tectonics. http://kids.earth.nasa.gov/...

### science

An asteroid in an elliptical orbit about the sun travels at 2.0 106 m/s at perihelion (the point of closest approach) at a distance of 3.8 108 km from the sun. How fast is it traveling at aphelion (the most distant point), which is 8.3 108 km from the sun?

### physical

An asteroid in an elliptical orbit about the sun travels at 3.9 106 m/s at perihelion (the point of closest approach) at a distance of 3.7 108 km from the sun. How fast is it traveling at aphelion (the most distant point), which is 8.6 108 km from the sun?

### math

To qualify for the race, each driver must complete 2 laps of the track at an average speed of 100 mi/h. Benjamin averages only 75 mi/h on his first lap. How fast must he go on his second lap to qulify for the race?

### physics

Lauren was playing hockey and took a 90 km/hr slap shot at the goal, 10 m away. If the goalie must move her glove 0.50 m to stop the puck, and her reaction time is 0.18 seconds, how fast must she move her glove?

### Inequalities

Shelby's test scores are 99, 91, and 85. If she must average at least 90 points to get an A in the class, what must she earn on the next test? Okay so this was my equation but it came out completely wrong. 99+91+85+x greater than or equal to 90 So what should the equation be?

### math

In math class, students must randomly draw a card that contains an equation that they must graph on the board. If the cards contain the equations 2y = 4x + 2, x(x + 1) = 0, 2x + y = 0, x = 2y , x2 + 1 = 0, and y - 2x = 0, then what is the probability that a student will graph ...

### math

Bairleys rectangular dog pen for his irish setter must have an area of 400 square feet. Also the length must be 50 feet longer than the width. Find the dimentions of the pen

### physics

A place kicker must kick a football from a point 38.2 m from a goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked the ball leaves the ground with a speed of 20.6 m/s at an angle of 53° to the horizontal.

### physics

In Bohr's model of the hydrogen atom, the radius of an orbit a. is proportional to n2. b. is smallest for the highest energy state. c. increases when a photon of light is emitted from an excited atom. d. can have any value that is larger than the ground-state radius. e. none ...

### global

why could it be said that the historic period is only a minute in comparison ti the 24 hours of the day? The historic period began about 5,000 years ago when writing was first developed in Mesopotamia (now Iraq). Modern man has existed for at least 100,000 years. The historic ...

### Physics

The earth rotates once per day about an axis passing through the north and south poles, an axis that is perpendicular to the plane of the equator. (a) Assuming the earth is a sphere with a radius of 6.38 106 m, determine the speed of a person situated at the equator. (b) What ...

### physics

A one tonne moon obiter is to approach the moon and orbit through 270 degrees at an altitude of 100km. During this period its rockets are to be turned off. What is the required velocity of the obiter at the entry point to prevent the vehicle from crashing into the moon?

### Mathematics

A space camera circles the Earth at a height of h miles above the surface. Suppose that d distance, IN MILES, on the surface of the Earth can be seen from the camera. (a) Find an equation that relates the central angle theta to the height h. (b) Find an equation that relates ...

### Physics

The sun has a mass of 1.99x10 30 kg the earth has a mass of 5.98x10 24 kg and is 1.496x10 11 m from the sun a) Calculate the force of gravity acting on the eaarth by the sun b) CAlculate the force of gravity acting on the sun by the earth