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

25,272 results, page 91

### Physics

how many coulombs must be on one object for it to be repelled with a force of 6.0 N by a second charge of 2.0uC at a distance of 1.0 m?

### Math

2 liters of cleaning solution is 65% ammonia. How much water must be added to dilute it to a 40% soulition?

### Math

The first term of a GP is 64 and the common ratio is 1/2.How many terms must be added to obtain a total of 127 1/2?

### english

Identify the subject, object, and verb in this sentence: Paralegals must have good ethics.

### chem 1211

What temperature change must 1.2mol of water undergo if the amount of energy changed is 23.7 J?

### Chemistry

At what speed must a human weighing 150.0 lb be traveling in order to have a wavelength at 650 nm?

### proportion and percentages problem

what must be added to 311 to make it equal to 87 1/2 per cent of 500

### Math

A sixth number will be added to the list. What must it be in order for the mean to be 12? (Use algebraic equation to help)

### Introduction to small engines

The distance the piston must travel from TDC to BDC is referred to as the of the engine

### GEOGRAPHY

ON A JOURNEY FROM NEWYORK TO LAGOS, TO CORRECT STANDARD TIME YOU MUST PUT THE HAND OF YOUR WATCH ......................

### Spelling

Mother is to brother as fly is to? 4 letters. Must contain scr, spr, str, or thr.

### Chemistry

If you add 13.75 mL of 1.35 M HCl to 22.80 mL of 0.955 M Ca(OH)2, will you neutralize all the Ca(OH)2? You must show data to support your answer.

### Chemistry

How many moles of NH4Cl must be added to 1.5L of 0.2 M solution of NH3 to form a buffer whose PH is 9.(Kb=1.8x10^-5)

### BIO 1010

1) Which of the following are fossil fuels? a. coal b. limestone c. coral skeleton d. petroleum e. choice a and d are both fossil fuels ANSWER: E 2) Satellite and other scientific data have shown that, over the past several decades, global temperatures have ____ and CO2 levels...

### PHYSICS!!

Two basketball players collide head on. play a weighs 80 kg and is travelling 2.5m/s to the right while player b weighs 68 kg and is travelling 1.2 m/s to the left. after collision player a is travelling at 1.0 m/s to the right. a. what is the change in momentum of player a? b...

### Chemistry

How many grams of propane must be burned to provide the heat needed to melt a 70.0-g piece of ice...? How many grams of propane must be burned to provide the heat needed to melt a 70.0-g piece of ice (at its melting point) and bring the resulting water to a boil (with no ...

### Physics

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

### economics

6) If average movie ticket prices rise by about 5 percent and attendance falls by about 2 percent, other things being equal, the elasticity of demand for movie tickets is about: A. 0.0 B. 0.4 C. 0.6 D. 2.5 7) When labor is the variable input, the average product equals the A. ...

### physics

A fisherman sets out upstream from Metaline Falls on the Pend Oreille River in northwestern Washington State. His small boat, powered by an outboard motor, travels at a constant speed v in still water. The water flows at a lower constant speed vw. He has traveled upstream for ...

### physics

A fisherman sets out upstream from Metaline Falls on the Pend Oreille River in northwestern Washington State. His small boat, powered by an outboard motor, travels at a constant speed v in still water. The water flows at a lower constant speed vw. He has traveled upstream for ...

### Earth science

a fault is observed in a road cut, but there is no obvious rock units to correlate on either side of the fault to determine relative movement. How might you determine or even infer whether the hanging wall has moved up or down relative to the footwall

1. earth has only a limited amount of land, yet land is a renewable resource, why? 2. trees are renewable resources, but some forests are not, why? 3. compare and contrast minerals and ores. 4. how could using ores contribute to an increase in air pollution?

### Science

Help with these questions. 1. Describe a disadvantage of using a telescope positioned in space. 2. What advantage is there to doing laboratory experiments on the International Space Station rather than doing the same experiments on Earth? 3. Explain why it is unlikely that ...

### Science

An area in your state has been flooded due to heavy rains. How might scientists from the three main branches of science interact in their study of the flood, its effects, and how future flooding might be controlled? Life science, Earth science, and physical scicence.

### physics

the first active volcano observed outside the earth was discovered in 1979 on Io, one of the moons of jupiter. the volcano was observed to be ejecting material to a height of about 2.00x10^5m. given that the acceleration of gravity on Io is 1.80 m/s^2, find the initial ...

### physical science

On the surface of the moon, where the acceleration due to gravity is about one-sixth that of Earth, a 100-kg astronaut would have a mass of_____ and a weight of _____ A. 100kg, 1000N B. 16.6kg, 166N C. 100kg, 166N D. 600kg, 1000N

### physics

Two pellets, each with a charge of 0.80 microcoulomb (8.0×10−7 C), are located 4.0 cm (4.0×10−2 m) apart. Find the electric force between them, which I solved for 3.6 N. I am stuck on the next part: What would be the mass of an object that would experience this ...

### Physics

Two different simple harmonic oscillators have the same natural frequency (f=5.60 Hz) when they are on the surface of the Earth. The first oscillator is a pendulum, the second is a vertical spring and mass. If both systems are moved to the surface of the moon (g=1.67 m/s2), ...

### calculus 2

An object falls off a 400-foot tower. With g=32ft/sec^2, as at the Earth’s surface, the object would hit the ground after 5 seconds. What would the acceleration due to gravity have to be to make it reach the ground in half the time?

### Science

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

### Social Studies

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

### Geometry

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

### Chem

The atomic numbers and masses must added up on both sides of the equation just as we must have the same number of atoms on each side of an equation when it is balanced. Ejection of a "thing" with 2 protons and 2 nuetrons is a He nucleus which is an alpha particle. 88Ra226 ==&...

### Physics

My last problem for the day: A) The centers of two 11.00 kg spheres are separated by 0.09 m. What is their gravitational attraction? I got 9.96 x 10^-7 N. B) What is the ratio of this attraction to the weight of one of the spheres (at the surface of the Earth)? I'm sure this ...

### Geology/Earth Science

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

### space

Consider a situation where immediately after birth, twins are separated. One continues to live on earth, while the other is whisked away in a space ship at 90% of the speed of light. After 65 years they are reunited. Will they look the same? Show proof of your answer through ...

### Language arts

1. Read the sentence from "Zoos: Joys or Jails?" What clue word is used to show contrast between the two points of view? "Although the circumstances and reasons for animals being in zoos vary, its concept has faults many don't notice during their visit with the animals." and ...

### Solvent

Question: A sample was placed on a chromatography column. Methylene chloride was used as the eluting solvent. All of the components eluted off the column but no separation was observed. What must have been happening during this experiment:? How would you change the experiment ...

### Writing Evaluation (Writeacher)

Should I revise anything? In my opinion, the use of “scary things” as entertainment is redundant. I mean, honestly, what on earth is so enjoyable about fear? Fear is what haunts us and frightened us even as young children. Yes, we are taught to face it, to not fear it, but...

### Chemistry

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

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

### Calculus

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

### Physics

An object in space is initially stationary relative to the Earth. Then, a force begins acting on the object, starting with a force of 0 N, and increasing at a uniform rate until the magnitude of the force is 56 N after the force has acted for 10 s. The body has a mass of 15 kg...

### physics

An object in space is initially stationary relative to the Earth. Then, a force begins acting on the object, starting with a force of 0 N, and increasing at a uniform rate until the magnitude of the force is 58 N after the force has acted for 25 s. The body has a mass of 10 kg...

### geography

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

### physics

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

### physics

Newton assumed that a gravitational force acts directly between Earth and the Moon. How does Einstein's view of the attractive force between the two bodies differ from Newton's view?

### Earth Sciencs

What are the different types of seafloor sediments and what are the factors that control the distribution of each major sediment type? Where does each major seafloor sediment type tend to accumulate in greatest quantity?

### science

The acceleration of gravity on the surface of Venus is 8.9m/s^2. Would a ball thrown upward on Venus return to the ground sooner or later than a ball thrown upward with the same speed on the earth?

### check my science hw please.

26. In the last few centuries, the number of species becoming extinct on Earth has A.decreased dramatically B. decreased slightly. C. increased slightly. D.increased dramatically I think it should be C.

### Physics

A wasp accumulates 1.0x10^-14C of charge while flying perpendicular to the earth's magnetic field of 4.0X10^-5T. How fast is the wasp flying if the magnetic force acting on it is 3.0x 10^-16N?

### science

the apparent magnitude of star is how bright they look to us we are on the earth looking up into space which would look brighter Small star Big star I think that is the big star thank you in advance

### Calculus

1. Chris makes an open-topped box from a 30-cm by 30-cm piece of cardboard by cutting out equal squares from the corners and folding up the flaps to make the sides. What are the dimensions of each square to the nearest hundredth of a centimetre, so that the volume of the ...

### english-what would you wish for

This was the question of the day What would be one wish that you would wish for if you had a chance. I would wish for Earth to stay as our home forever. Can I have your outlook on this?

### Calculus

for population in billions, where t is years since 1990: N(t) = 41/1+11 e^−0.1 t (b) According to this model, when will the earth's population reach 20.5 billion? During the year . How about 40.9 billion? During the year .

### earth

a student measures the velocity of a water in a stream as 2.5 meters pe second.the actual velocity of the water is 3.0 meters per second. what is the approximate percent deviation of the studen's measurement

### Physics

A ferry is crossing a river. The ferry is headed due north with a speed of 2.8 m/s relative to the water and the river’s velocity is 4.9 m/s to the east. a) What is magnitude of the boat’s velocity relative to Earth

### Physics

A ferry is crossing a river. The ferry is headed due north with a speed of 2.8 m/s relative to the water and the river’s velocity is 4.9 m/s to the east. a) What is magnitude of the boat’s velocity relative to Earth

### Science

In what way is erosion NOT like weathering? A)It is a force that changes the earth's surface B)It is a destructive force C)It changes rocks in some way D)It breaks down rocks I think D??

### Earth science

A sphere was dropped into water in a graduated cylinder as shown in the following diagram.The water level rose th the new level shown .What is the volume of the sphere

### Weight Is Force! Science

A space ship has a mass of 9000kg. the space ship is launched from Earth and lands on a distant planet where it has a mass of 390000 N. What is the acceleration of the gravity on this planet?

### 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 ...

### Physics

What is the work required to raise a 10. kg object from the surface of the Earth to a height of 2.0 m? 5.0 J 20. J 2.0 E2 J 2.0 E3 J My answer was 20. J but this was wrong. Is the answer 2.0 E2 J? A net force of 9.0 N acts through a distance of 3.0 m in a time of 3.0 s. The ...

### earth

the area around the great lakes was once covered by thick sheets of ice. Use the principal of isostasy to explain how the melting of these ice sheets has effected the land around the lakes?

### 3rd homework

the water cycle! lesson I water on earth type of water 1. ? where found 2. ? 3 ? 4 ? uses 5. ? 6. ? 7. ? 8. ? where found 9. ? 10. ? 11. ? uses 12. ? 13. ? 14. ? 15. where salt and fresh water meet is called an ? please help with the ?'s. I have no idea what to fill in. :-(

### physics

A ball is thrown straight upward and then returns to the earth. choosing the positive direction to be upward, sketch a graph of the velocity of this ball against time. where does the velocity change direction? Explain?

### physical science

The acceleration of gravity on the surface of Venus is 8.9 m/s2. Would a ball thrown upward on Venus return to the ground sooner or later than a ball thrown upward with the same speed on the earth?

### physical science

the acceleration of gravity on the surface of venus is 8.9 m/s2. would a ball thrown upward from venus return to the ground sooner or later than a ball thrown upward with the same speed on the earth?

### physics

Estimate the time difference between the longest amount of daylight in one day and the shortest amount of daylight on one day in seconds over the course of a year if you lived on the Earth's equator

### speed

2 rockets are launched. The first one travels 9000 mph. 15 Minutes later the second launched at 10000 mph. What is the distance at wich both rockets are an equal distance from earth?

### Earth science

What kind of front sometimes spawns tornadoes between an advancing cold and dry air mass and a warm moist air mass? 1) cold 3) stationary 2) warm 4) occluded

### Chemistry

the effective incoming solar radiation per unit area on earth is 342 W/M^2. of this radiation, 6.7 W/m^2 is absorbed by CO2 at 14993 nm in the atmosphere. how many photons at this wavelength are absorbed per second in 1 m^2 by CO2?

### College Physics

If a certain amount of ideal gas occupies a volume 9.5 m3 with a pressure of 3.1 atm and temperature 5.4 oC on earth, what would be its volume on another planet, where the temperature is 5.3oC and the pressure is 7.4 atm ? The answer is in unit of m3

### MATH

A set of numbers has “the triple-sum property” (or TSP) if there exist three numbers in the set whose sum is also in the set. [Repetitions are allowed.] For example, the set U = {2, 3, 7} has TSP since 2 + 2 + 3 = 7, while V = {2, 3, 10} fails to have TSP. (a) Suppose the ...

### Geog

if each time zone is 15 degrees in width who many time zones are there around the earth? Simple math problem. There are 360 degrees around the world. Divide 360 by 15.

### physics

A person falls from a height of 2.0m on earth(a=g=9.8m/s2). What acceleration is necessary for them to stop over 30 cm (assuming they bend their knees)? what if they don't bend their knees hence stop over a distance of 1 mm?

### Earth Science

what is the dewpoint temperature of a kilogram of air when a psychrometer measures an 8 degree Celsius dry-bulb temperature and a 6 degree Celsius wet-bulb reading?

### PHYSICS

HOW DO U COMPUTE g USING THE EQUATION g=GM/r^2 WHEN GIVEN THE QUESTION IN THIS FORM: "COMPUTE g AT A HEIGHT OF 4 RE ABOVE THE SURFACE OF EARTH" -basically how can i find the answer to a question given in this form

### physics

A ferry is crossing a river. If the ferry is headed due North with speed of 2.5m/s relative to the water and the river's velocity is 3 m/s to the east, what will the boat's velocity be relative to Earth?

### Physics

A 6 kg brick is falling at a rate of 48.9 m/s toward the earth at a current height of 14 m. What is the total mechanical energy of the brick? (total mechanical energy= Eg+Ek+Eel) What is the answer in Joules?

### Physics

A 6 kg brick is falling at a rate of 48.9 m/s toward the earth at a current height of 14 m. What is the total mechanical energy of the brick? (total mechanical energy= Eg+Ek+Eel) What is the answer in Joules?

### English

In the movie "Like Stars on Earth," we can see the names 'Nikumbh' and ' Awasthi.' They are main characters in the Indian movie. How do you pronounce the two names? Do you pronounce 'bh' in Nikumbh'?

### LA

Read the passage. What technique is the author using to develop point of view? Though zoos are meant to be a joy to viewers and teach lessons about our earth, the zoo jails its inhabitants and passes on faulty knowledge A) State a claim B) Persuasive Language C) Supporting ...

### LA

2. Read the passage. What technique is the author using to develop point of view? "Though zoos are meant to be a joy to viewers and teach lessons about our earth, the zoo jails its inhabitants and passes on faulty knowledge." a. state a claim b. persuasive language c. ...

### Spanish

This is my assignment: Imagine you are babysitting your little brother. Write a total of 5 Spanish sentences using tú commands telling your little brother what to do. Write 3 sentences using regular verbs. Write 2 sentences using irregular verbs. You can use the examples ...

### Chemistry

If you divide the molar mass of a compound by the empirical formula mass, what is the result? That division should be VERY close to a whole number. Usually, 0.9 to 1.1 or 1.9 to 2.1 (all depending upon the accuracy and precision of experimental data). That number is the number...

### Earth Sciences, Geology

What means by 'Gemstone minerals'? Is there any difference between gemstone, minerals and gemstone minerals?

### Exploring Space

what wud hold the cable of a space elevator up? Would it be earth's gravity holding the cable of a space elevator up?

### Geog

How many minutes does it take for the earh to rotate through 1 degree of longitude? The earth has 360 degrees of longitude. It rotates every 24 hours. There are 1440 minutes in a day. Divide 1440 by 360 to get your answer.

### Earth Science

Which particles can wind move most easily? Sand, silt, pebbles, or gravel? I put sand but my teacher marked it wrong. Would it be silt? Pebbles and gravel are pretty heavy.

### college

Suppose that it takes about 3 days for a space vehicle to travel from Earth to the moon. About how long would it take the same space vehicle traveling at the same speed to reach Pluto?

### physics

the speed of a car can be measured in s^-1 m right... it could be said that a speed of a car the velocity was 15 s^-1 m which is perfectly acceptable... by definition 15 s^-1 m can also be written as 15 Hz m just by definition... what on earth does that mean??? is velocity not...

### Environmental Sciencee

2. The water resources of the Earth are located in a. salt water fround in the ocean b. fresh water found in icecaps and glaciers c. fresh water found in rivers, lakes, and streams d. all of the above D

### Earth Science

How much more energy is released in a 5.0 magnitude earthquake than a 4.0 magnitude earthquake? I know that a tenfold increase in wave amplitude equals an increase of 1 on the scale so 1 to 2 = 10times so does that mean that 2 to 3 would be 10 more times?

### english

separate the sentence with a line between the complete subject and the complete predicate Three-fourths of the earth / is covered by water, and most of it is salty ocean water. is the line in this simple sentence correct?? THANKS

The diameter of the sun is approximately 1.4x10 to the power 9 km and the diameter of earth is approximately 1.28 x10 to the 4th power km. About how many times earths diameter is the suns diameter. Write in scientific notation.

### chem

What is the disadvantage of the English system? Please and thank you!!! The advantage of the metric system is that units differ by a factor of 10 (or 100, or 1000, etc) so it makes it easy to convert from one unit to another simply by moving the decimal point. For the English ...

### PRE-CALC

Roland's Boat Tours sells deluxe and economy seats for each tour it conducts. In order to complete a tour, at least 14 economy seats must be sold and at least 5 deluxe seats must be sold. The maximum number of passengers allowed on each boat in 45. Roland's Boat Tours makes \$...

### astronomy

Arcturus is about half as hot as the Sun but is about 100 times more luminous. What is its radius campared to the sun. If Arcturus is half as hot, it radiates (1/2)^4 = 1/16 as much as the sun PER UNIT AREA. But since it radiates 100 times more totally, it must have 1600 times...

### science

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