Friday

September 4, 2015
Number of results: 6,369

**physics**

Find the distance (measured in earth radii, RE) from the center of the earth to a point outside the earth where the acceleration of gravity due to the earth is exactly one ninth of its value on the surface of the earth.
*April 24, 2010 by Muhammad*

**Physics**

At the heighest point on earth, the distance to the center of the earth is approximately equal to 1.0014 times the radius of the earth. What would be in N/kg the magnitude of the gravitational field (g) due to the earth at that position? Assume 9.8 N/kg for g at the surface of...
*September 6, 2011 by Hannah*

**Physics**

What is the Earth's gravitational force on you when you are standing on the Earth and when you are riding in the Space Shuttle 380 km above the Earth's surface? Answer as a fraction of the surface gravity of Earth. (The Earth's radius is 6400 km.)
*January 27, 2015 by Kayla*

**physics**

What is the distance from the Earth's center to a point outside the Earth where the gravitational acceleration due to the Earth is 1/22 of its value at the Earth's surface? _ m
*December 18, 2009 by asia*

**physics**

What is the distance from the Earth's center to a point outside the Earth where the gravitational acceleration due to the Earth is 1/45 of its value at the Earth's surface?
*February 22, 2010 by Anonymous*

**phy**

What is the distance from the Earth's center to a point outside the Earth where the gravitational acceleration due to the Earth is 1/12 of its value at the Earth's surface?
*September 17, 2010 by ami*

**Physics**

What is the distance from the Earth's center to a point outside the Earth where the gravitational acceleration due to the Earth is 1/20 of its value at the Earth's surface?
*October 3, 2010 by Eden*

**colllege physics**

What is the distance from the Earth's center to a point outside the Earth where the gravitational acceleration due to the Earth is 1/45 of its value at the Earth's surface?
*February 22, 2010 by Anonymous*

**physics**

As you walked on the moon, the earth’s gravity would still pull on you weakly and you would still have an earth weight. How large would that earth weight be, compared to your earth weight on the earth’s surface? (Note: The earth’s radius is 6378 km and the distance separating ...
*March 31, 2011 by olga*

**Astro**

What is the distance in meters from the Earth's center to a point out-side the Earth where the gravitational acceleration due to the Earth is 1/20 of its value at the Earth's surface?
*October 2, 2009 by Ryrya*

**Physics**

When we say that the weight of an object is Mg, and that g = 9.8 N/kg, what assumptions are we making? Which of the below? The distribution of mass in the earth is spherically symmetric. The density of the earth is the same everywhere. The earth's interior is solid everywhere...
*January 25, 2013 by arcos15*

**Physics**

When we say that the weight of an object is Mg, and that g = 9.8 N/kg, what assumptions are we making? Which of the below? -The distribution of mass in the earth is spherically symmetric. -The density of the earth is the same everywhere. -The earth's interior is solid ...
*January 25, 2013 by arcos15*

**Algebra**

The gravitational force between an object & the Earth is inversely proportional to the square of the distance from the object to the center of the Earth. If an astronaut weighs 210 lbs on the surface of the Earth, what will he weigh 100 miles above the Earth? Assume that the ...
*April 29, 2011 by Crystal*

**Physics HELLLPPPP**

When we say that the weight of an object is Mg, and that g = 9.8 N/kg, what assumptions are we making? Which of the below? -The distribution of mass in the earth is spherically symmetric. -The density of the earth is the same everywhere. -The earth's interior is solid ...
*January 25, 2013 by NATTT*

**math**

The mean radius of the Earth is 6.37 x 106 meters (m). Assuming the earth can be modeled as a perfect sphere a. In cubic meters (m3 ) what is the volume of the Earth? b. In meters (m) what is Earth’s circumference? c. If the mean density is 5.515g/cm3, what is the Earth’s mass...
*February 21, 2011 by Rocio Aguilera*

**Science**

Luis wanted to create a clay model of earth and the sun. To show how Earth rotates, Luis wants to use a toothpick to represent Earth's axis of rotation. Where should Luis place the toothpick? A. Horizontally through Earth in the direction Earth is traveling B. Vertically ...
*November 20, 2013 by Anna*

**physics**

What is the acceleration due to gravity at a distance of 1.2 Earth radii above Earth�s surface? Use M_{Earth} = 5.972 x 10^{24} kilograms and r_{Earth} = 6370 km a_{gravity} =______________{m}{s^2}
*March 3, 2014 by Melissa*

**math**

What is the acceleration due to gravity at a distance of 1.2 Earth radii above Earth�s surface? Use M_{Earth} = 5.972 x 10^{24} kilograms and r_{Earth} = 6370 km a_{gravity} =______________{m}{s^2}
*March 3, 2014 by Melissa*

**Calculus Physics**

Imagine a spaceship on its way to the moon from the earth. Find the point, as measured from the center of the earth, where the force of gravity due to the earth is balanced exactly by the gravity of the moon. This point lies on a line between the centers of the earth and the ...
*March 2, 2015 by danny*

**physics entry **

A meteor headed straight towards the earth has an approach speed of 2.00e3 m/s at a distance of 7 earth radii from the center of the earth. What will be its speed when it reaches earth a 6.38e6 m(ignore the effects of atmosphere)?
*November 17, 2009 by Andy *

**earth**

Compared with the strength of Earth's gravity at its surface, how much weaker is gravity at a distance of 11 Earth radii from Earth's center?
*September 29, 2011 by chris*

**earth**

A particle weighs 120 N on the surface of the earth. At what height above the earth's surface will its weight be 30 N? Radius of the earth = 6,400 km.
*May 31, 2012 by Anonymous*

**physics**

Which of the following best describes the strength of the gravitational force on Earth due to your mass? A) It is zero as long as you are standing on Earth’s surface. B) It is much greater than Earth’s gravitational force on you because Earth’s mass is so great. C) It is equal...
*May 15, 2012 by blue ivy*

**Physics please help**

How far from the center of the Earth (in km) is the center of mass of the Earth + satellite system if the satellite has a mass of 6560 kg and is in orbit 46200 km above the surface of the Earth. The mass of the Earth is 5.98 * 10^24 kg and the radius of the Earth is 6370 km.
*November 14, 2011 by Me*

**English**

What makes our earth sick? - Steel cans make the earth sick. - Shampoo makes the earth sick. - Empty bottles make the earth sick. - Plastic bags make the earth sick. - ___________ make/makes the earth sick. (Are the answers all grammatical? What other expressions can we use in...
*November 17, 2009 by rfvv*

**earth**

The Earth orbits the Sun once every 365 days. The distance between the Earth and the Sun is 1.5 x 1011 m. What is the average orbital velocity of the Earth as it travels around the Sun?
*November 21, 2010 by Anonymous*

**earth-physics**

The Earth has an angular speed of 7.272 10-5 rad/s in its rotation. Find the new angular speed if an asteroid (m = 1.07 1022 kg) hits the Earth while traveling at a speed of 1.30 103 m/s (assume the asteroid is a point mass compared to the radius of the Earth) in each of the ...
*February 26, 2012 by huiol*

**physics**

Find the speed of a satellite in a circular orbit around the earth with a radius 2.69 times the mean radius of the earth; Radius Earth= 6.37E+3km; Mass Earth= 5.98E+24kg.
*March 11, 2014 by Marie*

**Physics**

The Earth has an electric field with magnitude roughly 100 N/C at its surface. A) Assuming there is a point charge at the earth's center creating this field, how much charge does the earth posses? Treat the earth as a sphere of radius 6.37 * 10^6 m. B)As the earth orbits the ...
*March 6, 2008 by jenish*

**Physics help!**

How far from the center of the Earth (in km) is the center of mass of the Earth + satellite system if the satellite has a mass of 6560 kg and is in orbit 46200 km above the surface of the Earth. The mass of the Earth is 5.98 * 10^24 kg and the radius of the Earth is 6370 km
*November 14, 2011 by Me*

**physics**

calculate the centripetal acceleration of the earth in its orbit around the sun and the net force exerted on the earth. What exerts this force on the earth? Assume that the earth's orbit is a circle of radius 1.50x10^11m. (earth's mass= 5.98x10^29kg, Sun's mass= 1.99x10^30kg)
*April 27, 2010 by krista*

**Physics**

When the space shuttle (mass of the shuttle = 2 x10^6 kg) was at the outer limit of Earth's atmosphere (distance = 350 km above Earth's surface), astronauts measured the gravitational force from Earth to be equal to 1.7 x 10^7 newtons. Assuming that both Earth and the shuttle ...
*May 20, 2012 by Leila*

**science**

A distant spaceship carrying a red headlight, emitting light with wavelength 600nm, is heading towards the earth. Observers on the earth detect the light from the headlight as ultraviolet light with wavelength 200nm. What is the velocity of the spaceship? b) As the space ship ...
*March 9, 2014 by Relativity quest. help pls*

**geometry**

The Hubble Space Telescope is orbiting Earth 600 km above Earth's surface. Earth's radius is about 6370 km. Use the Pythagorean Theorem to find he distance a from the telescope to Earth's horizon. Round your answer to the nearest ten kilometers.
*December 9, 2008 by sarah*

**Physics**

Calculate the force of gravity on a spacecraft 19200 km (3 earth radii) above the Earth's surface if its mass is 1600 kg. Hint: At three earth radii from the surface of the Earth, the gravity force (weight) of the spacecraft will be reduced to (1/4)^2 = 1/16 of the weight when...
*January 7, 2007 by Scotty*

**science**

The pull of gravity keeps the Moon in orbit around Earth. The distance between the Earth and Moon is about 380,000 kilometers. A crew of astronauts leaves Earth on a Monday and lands on the Moon on a Thursday. They land on the side of the Moon facing away from the Earth. On ...
*February 2, 2012 by Bryan*

**physics **

radius R of the orbit of a geosynchronous satellite that circles the earth. (Note that R is measured from the center of the earth, not the surface.) You may use the following constants: The universal gravitational constant G is 6.67×10−11N⋅m2/kg2. The mass of the ...
*December 14, 2014 by cara*

**physics/math**

Calculate the magnitude of the gravitational force between the Earth and an m = 6.00 kg mass on the surface of the Earth. The distance to the center of the Earth from the surface is 6.37×103 km and the mass of the Earth is 5.98×1024 kg.
*March 22, 2013 by HP*

**earth**

a space traveller determines the radius of a planet to be half of earth . After landing on its surface , he finds the acceleration due to gravity to be twice of that of surface of earth. Find the ratio of mass of planet to the earth
*September 19, 2012 by hanu*

**Physics**

Determine the ratio of Earth's gravitational force exerted on an 80-kg person when at Earth's surface and when 1000km above Earth's surface. The radius of Earth is 6370 km. I have tried (6370)^2/(7370)^2 = 0.747 and it is wrong??
*February 5, 2015 by Anonymous *

**Physics**

The earth has about 80 times the mass of the earth’s moon. The gravitational force exerted on the moon by the earth has what relation to the gravitational force exerted on the earth by the moon? 1. the same as 2. zero; the earth exerts a force on the moon,but the moon is too ...
*January 18, 2015 by Tiffany*

**Physics**

A 1.0kg mass weighs 9.8 Newton on earth's surface, and the radius of Earth is roughly 6.4 x 10 to the power of 6. The mass of the earth is 6.02 x 10 to the power of 24. Calculate the average density of Earth?
*December 24, 2012 by Rebecca*

**English**

1. What makes our earth sick? Gases from cars make the earth sick. Paper cups make the earth sick. _________ make(s) the earth sick. _________ make(s) the earth sick. (Would you name what makes the earth sick? The more,the better. The things suitable for the subject? Thank you.)
*November 10, 2009 by rfvv*

**Physics**

The Hubble Space Telescope orbits the Earth at an approximate altitude of 612 km. Its mass is 11,100 kg and the mass of the Earth is 5.97×1024 kg. The Earth's average radius is 6.38×106 m. What is the magnitude of the gravitational force that the Earth exerts on the Hubble?
*April 6, 2011 by Denise*

**Physics**

The Hubble Space Telescope orbits the Earth at an approximate altitude of 612 km. Its mass is 11,100 kg and the mass of the Earth is 5.97×1024 kg. The Earth's average radius is 6.38×106 m. What is the magnitude of the gravitational force that the Earth exerts on the Hubble?
*April 6, 2011 by Denise*

**physics**

Assuming the Earth's magnetic field averages about 0.50×10−4 T near Earth's surface, estimate the total energy stored in this field in the first 15km above Earth's surface. The radius of Earth is 6380 km.
*March 23, 2014 by Jennifer*

**phy.**

check my understanding please. Larry weighs 300 N at the surface of the earth. what is the weight of the earth in the gravitational field of Larry? -would it still be 300 N an astronaugt lands on a planet that has twice the mass as earth and twice the diameter. how does the ...
*October 16, 2007 by Julie*

**physics**

When a spacecraft travels from Earth to the Moon, the gravitational force from Earth initially opposes this journey. Eventually, the spacecraft reaches a point where the Moon's gravitational attraction overcomes the Earth's gravity. How far from Earth must the spacecraft be ...
*October 4, 2012 by Garcia*

**physics**

A child learns in school that the earth is traveling faster than 100,000 kilometers per hour around the sun, and in a frightened tone asks why we arent swept off. What statement about the motion of the Earth is, on average,true? A. We are traveling slower than the Earth B. We ...
*July 12, 2011 by alexa*

**Physics:upward acc of earth**

If the Earth's gravitational force causes a falling 93 kg student to accelerate downward at 9.8 m/s2, determine the upward acceleration of the Earth during the student's fall. Take the mass of the Earth to be Mearth = 5.98 x 1024 kg. Answer in units of m/s2.
*April 20, 2010 by HELP ME!!*

**earth**

how far should a man go from the centre of the earth such that his weight is 1\4th of that on the earth?radius=6400km.
*October 20, 2010 by jahnvi*

**earth**

if you are in a spacecraft moving away from earth, how would your weight change as your distance from earth increases?
*May 31, 2011 by deanna*

**earth**

When earth is seen from outer space,it looks mainly blue. This is because most of the earth is covered with.
*March 14, 2015 by leslie*

**environmental science**

The earth's differentiation and size were significant factors for life on Earth because Earth's composition and gravitational attraction
*December 28, 2010 by Anonymous*

**physics**

Calculate the force of gravity on a 12 kg mass if it were 6.4 106 m above Earth's surface (that is, if it were 2 Earth radii from Earth's center.)
*January 24, 2011 by Anonymous*

**physics**

Calculate the force of gravity on a 12 kg mass if it were 6.4 106 m above Earth's surface (that is, if it were 2 Earth radii from Earth's center.)
*January 24, 2011 by taylor*

**physics**

Calculate the force of gravity on a 10 kg mass if it were 6.4x10^6 m above Earth's surface (that is, if it were 2 Earth radii from Earth's center.)
*January 26, 2012 by ginger*

**physics-mechanics**

A 1.0 kg mass weighs 9.8 N on Earth's surface, and the radius of Earth is roughly 6.4 x 10^6 m. Calculate the average density of Earth
*December 27, 2012 by Rebecca*

**physics**

Calculate the radius of a “super- Earth” with 10 times the mass of Earth, using Earth data as a starting point.
*November 24, 2014 by dale*

**earth**

The radius of the Earth is approximately 3,960 miles. Find the approximate surface-area-to-volume ratio of the Earth.
*January 23, 2015 by Anonymous*

**physics- please help me!**

Earth turns on its axis approximately once every 24 hours. The radius of Earth is 6.38 X 10^6 m. a.) If some astronomical catastrophe suddenly brought Earth to a screeching halt (a physical impossibility as far as we know), with what speed would Earth's inhabitants who live at...
*December 9, 2008 by rory*

**Science**

Compared with the strength of Earth's gravity at its surface, how much weaker is gravity at a distance of 10 Earth radii from Earth's center? At 20 Earth radii?
*June 13, 2013 by Mia*

**earth**

A satellite's escape velocity is 6.mi./sec, the radius of the earth is 3960 mi, and the earth's gravitational constant (g) is 32.2 ft./sec^2. How far is the satellite from the surface of the earth?
*December 4, 2013 by Ernie*

**college**

Calculate the force of Earth's gravity on a spacecraft 12,800 km (2 Earth radii) above the Earth's surface if its mass is 1550 kg.
*February 22, 2010 by Anonymous*

**physics**

A boulder weighs 800N at the surface of the earth. What would be its weight at a distance of three earth's radii from the center of the earth?
*July 7, 2010 by weng*

**physics**

A boulder weighs 800N at the surface of the earth. What would be its weight at a distance of three earth's radii from the center of the earth?
*July 8, 2010 by weng*

**earth science**

describe a possible pathway of carbon through the four spheres of the earth.Identifty what each the fourspheres of the earth contains
*February 13, 2011 by jason*

**Science**

What is the circular velocity of an Earth satellite 1000. km above Earth's surface? (Note: Earth's average radius is 6371 km.)
*June 13, 2013 by Mia*

**Physics**

The Earth has an angular speed of 7.272·10-5 rad/s in its rotation. Find the new angular speed if an asteroid (m = 3.45·1022 kg) hits the Earth while traveling at a speed of 4.41·103 m/s (assume the asteroid is a point mass compared to the radius of the Earth) in each of the ...
*November 8, 2012 by Joe Frank*

**physics help**

The earth orbits the sun once a year (3.16 10^7 s) in a nearly circular orbit radius 1.50 10^11 m. With respect to the sun, determine the following. (a) the angular speed of the earth 1 rad/s (b) the tangential speed of the earth 2 m/s (c) the magnitude and direction of the ...
*November 19, 2010 by john*

**Physics HELP!!**

What is the acceleration due to gravity at 7220km above the Earth's surface? Take the radius of the Earth to be 6.37e6m and the mass of the Earth to be 5.972e24kg.
*October 16, 2012 by LS*

**physics**

3. A satellite of mass 500 kg orbits the Earth with a period of 6000 s. The Earth has a mass of 5.98 x 1024 kg. (a) Calculate the magnitude of the Earth's gravitational force on the satellite. (b) Determine the altitude of the satellite above the Earth's surface.
*October 15, 2012 by BO*

**maths**

The Weight of an object varies inversely as the square of its distance from the centre of the earth.the weight of a spacecraft is observed to be only a quater of its weight on earth.How far is the spacecraft from the surface of the earth? [take radius of the earth to be 6400km ]
*July 28, 2015 by ashong benjamin*

**principles of physics**

If the Earth had two identical moons in one circular orbit, and the moons were as far apart in that orbit as they could be, the center of gravity of the Earth-moons system would beA) at the center of the Earth.B) outside the Earth, but beyond the orbital path of the moons.C) ...
*March 2, 2012 by CHRIS*

**physics**

If the Earth had two identical moons in one circular orbit, and the moons were as far apart in that orbit as they could be, the center of gravity of the Earth-moons system would beA) at the center of the Earth.B) outside the Earth, but beyond the orbital path of the moons.C) ...
*March 3, 2012 by Mrs G*

**science **

A person who weighs 600 newtons on Earth would weigh only 100 newtons on the Moon. Which statement best explains why? A.The circumference of Earth is larger than that of the Moon. B.The density of Earth is greater than that of the Moon. C.The mass of Earth is greater than that...
*February 17, 2014 by victoria *

**Math**

The gravitational acceleration, g, on the Earth is proportional to the mass, M, of the Earth and inversely proportional to the square of the distance, r, from the Earth's center. If the gravitational acceleration on the center of the Earth is 9.8 m/s^2, what is the ...
*April 1, 2013 by Lorie*

**Physics**

A projectile is fired vertically from Earth's surface with an initial speed v0. Neglecting air drag, how far above the surface of Earth will it go? (Use any variable or symbol stated above along with the following as necessary: ME for the mass of the Earth, rE for the radius ...
*April 11, 2013 by Rachel*

**Physics**

Escape velocity from the surface of earth depends upon mass of the earth and radius of the earth. Find the realtion between these quantities dimensionely.
*April 5, 2009 by Akash*

**math**

Calculate the speed of an artificial earth satellite, assuming that it is travelling at an altitude h of 140 Km above the surface of the earth where g=9.8m/s2. The radius of earth R is 6373Km.
*August 2, 2010 by alobi*

**physics**

A satellite of mass m in a circular orbit at a height of 400Km above the earth's surface. What is the Radius of the Earth (given: 6.35 * 10^6) with respect to the center C of the Earth?
*April 23, 2011 by Lisa*

**science**

How far away from the earth does acceleration due to gravity become 1% of its value at the earth's surface. Assume that the earth is a sphere of radius 638000000cm.
*September 30, 2011 by Derrick*

**Physics**

Compute the angular momentum of the earth arising from the following motions. (a) Earth's orbital motion around the sun. (b) Earth's rotation on its axis.
*October 22, 2012 by Pat*

**physics**

I need help! i don't know how to do this problem. average atmospheric pressure at earth's surface is 1.01 x 10^5 N/m^2. Earth's radius is 6.37 x 10^6m. Show that the total weight of earth's atmosphere is about 5.15 x 10^19 N.
*May 28, 2013 by Chandler*

**physics**

A satellite is in a circular orbit around the Earth at an altitude of 3.30 106 m. (a) Find the period of the orbit. (Hint: Modify Kepler's third law so it is suitable for objects orbiting the Earth rather than the Sun. The radius of the Earth is 6.38 106 m, and the mass of the...
*February 22, 2015 by alba*

**Physics **

A spaceship is on a straight-line path between the Earth and the Moon. At what distance from Earth is the net gravitational pull on the probe from the Earth and the moon zero? Mass of Earth = 6×10^24 kg. Mass of Moon = 7×10^22 kg. Can someone please confirm if my answer of ...
*August 9, 2015 by Yoyo*

**physics**

GPS satellites orbit the earth about 20,000 km above the surface of the earth. The radius of the earth is 6,371 km. What is the acceleration due to earth’s gravity on the GPS satellites? i've tried fooling around with the A = V^2/ R and V = 2pir/T equations, but I cant seem to...
*May 1, 2015 by Dylan*

**Pearson**

Calculate the acceleration due to the rotation of the Earth of a person in a location 22° northern geographical latitude. Use R Earth = 3,680 km for the value of the radius of the Earth.
*November 4, 2010 by Crystal*

**Physics**

When a spacecraft travels from the Earth to the Moon, both the Earth and the Moon exert a gravitational force on the spacecraft. Eventually, the spacecraft reaches a point where the Moon's gravitational attraction overcomes the Earth's gravity. How far from the Earth's surface...
*October 13, 2012 by Sam*

**physics**

Two meteoroids 250,000 km from Earth are moving at 2.1 km/s. Meteor one is headed in a straight path for Earth, while meteor two is on a path that will come within 8500 km from the Earth's center. (A) What is the speed of the first meteroid when it strikes Earth. (B) What is ...
*March 17, 2009 by James*

**Physics**

Two meteoroids 250,000 km from Earth are moving at 2.1 km/s. Meteor one is headed in a straight path for Earth, while meteor two is on a path that will come within 8500 km from the Earth's center. (A) What is the speed of the first meteroid when it strikes Earth. (B) What is ...
*March 19, 2009 by James*

**physics**

The Moon's mass is 7.34 x 10^22 kg, and it is 3.8 x 10^8 away from Earth. Earth's mass if 5.97 x 10^24 kg. a. Calculate the gravitional force of attraction between Earth and the Moon. b. Find Earth's gravitional field at the moon. GIVEN: Moon's mass = 7.34 x 10^22 kg Earth's ...
*December 24, 2009 by Heart*

**physics**

can you walk me through this problem At what distance from teh Earth will a spacecraft on the way to the Moon esperience zero net force due to these two bodies because the EArth and Mon pull with equal and opposite forces? mass of earth = m1 = 5.98 E 24 kg mass of moon = m2 = ...
*September 13, 2009 by Physics*

**calculus**

the weight of a person on or above the surface of the earth varies inversely as the square of the distance the person is from the center of the earth. if a person weighs 180 pounds on the surface of the earth and the radius of the earth is 3900 miles, what will the person ...
*June 23, 2014 by Anonymous*

**Physics **

A spaceship is on a straight-line path between the Earth and the Moon. At what distance from (the centre of) Earth is the net gravitational pull on the probe from the Earth and the moon zero? Mass of Earth = 6×10^24 kg. Mass of Moon = 7×10^22 kg. The distance from the Earth to...
*August 14, 2015 by Jim*

**physics**

The auroral zone is defined by the last field line from the Earth that returns to the Earth. If the field of the earth extends no further than 10RE in the sunward direction, at what angle (in degrees) in the picture above does the last field line that returns to the earth on ...
*April 10, 2013 by Ruben *

**puzzles**

does this puzzle mean "down to earth" ------------- this is a box [ ] [ ] [ ] [ earth earth ] -------------
*April 13, 2009 by Delaney*

**earth science**

What are two lines of evidence that indicate that earth is rotating? What is the motion of the stars at night? What does the Sun do in the day? i want to seach features of the earth in its inner structure
*August 30, 2006 by steph*

**Earth Science**

Earth is always changing. What are two forces that cause the earth's surface to constantly change and what are their effects on the planet? Please answer within a few minutes.
*November 4, 2009 by Elizabeth*

**AP environmental Science**

What formula would i use to solve: If the earth has an annual growth rate of 1.2% how many people are added to the earth each year? what will be the population of earth in 2050? thanks, any help is appreciated!! :D
*October 16, 2011 by Nicole*