If the surface gravity of the moon is 1/6 of the earth, why isn't the mass of the moon 1/6?

Answer 1

Because while gravity may be directly proportional to Mass, it's also inversely proportional to the square of the radius. If the moon had the same radius as the Earth and 1/6 gravity, that would mean it had 1/6 mass, but the moon has a smaller radius that the Earth.

Answer 2

Because the Moon has a smaller diameter than the Earth. The strength of gravity varies with the mass and inversely with the square of the distance from the CENTER OF MASS, not distance from the surface of the body. The Earth is about 8,000 miles in diameter, so we on the surface are 4,000 miles from the center of mass. The Moon is only about 2,200 miles in diameter, so on the surface you are only 1,100 miles from the center. That is almost 4 times closer than on Earth, so the Moon has almost 16 times more gravitational pull that you might expect just from the mass difference alone.

Answer 3

The mass of the Earth is 80.3 times the mass of the Moon.The gravity of the Earth is about 6 time that of the Moon. The reason is that the Earth is denser than the Moon.It has a gravtity time of Te=802 seconds. While the Moon has a gravity time Tm=1068.09seconds
Acceleration on earth surface is(Ae)= Radius of earth /Time^2 at surface=9.8 meteres/seconds^2

Acceleration at moon surface (Am)=(moonradius=1785km)/Tm^2
equals=1.56467 Meters/seconds^2

Ae/Am = 9.8/1.56=6.3
The gravity time on the surface of the moon is Inversely proportional to the Square root of its acceleration(gravity)

Answer 4

Now, that is an interesting question.

The mass of the Earth is 5.9720E+24 kg and the mass of the Moon is 7.3500E+22 kg. Divide that out and you get 1.2307E-02. Much less then the ratio of gravitation forces which is 1.6571E-01.

There is, of course, a very good reason for this. The radius of the Moon is much less than the radius of the Earth.

The formula for finding gravitational force is g=Gm/r².

As you can see, a difference in the radius affects the force much more than the mass.

Answer 5

The mass of The moon in moon is 1/6 th of the weight that it would weigh on earth. This is the mass of moon 7.3477×10^22 kg.

Hope that helps

Answer 6

because of fact its smaller and the stress of gravity is inversely proportional on your distance from the centre of the planet. So, if the moon's radius grow to be 4 circumstances smaller than the earth then the stress may well be made sixteen circumstances greater desirable. in spite of the undeniable fact that, if its density grow to be the comparable then its quantity and mass may well be sixty 4 circumstances much less. ordinary, this might make its gravity 4 circumstances decrease than the earth's.

Answer 7

The answer above is correct. The reason is Gravity is = G*mass1*mass2 / Radius^2

(G is a constant) mass1 is moon, mass2 is you or any object. Radius is distance from center of gravity.

So when on the surface of the moon, ur distance from center of gravity is R. The farther u are away from the center of gravity, the less force there is, eventhough the mass stays the same.

Answer 8

Gravity is not directly proportional to mass. The equation is more complex than that.

Jupiter's gravity is only 12 times Earth's, yet it is about 300 times the mass of Earth.

Answer 9

The force of gravity is a particular form of energy. Stephen Hawking in “A Brief History of Time,” page 92, paragraph 3, states; “Like light, gravitational waves carry energy away from the objects that emit them.” We find that in order for a gravitational field to form, there must exist a particular energy structure. This is described in the physics trilogy, which is: E = mc2, m = E/c2, and c2 = E/m. The last is that of a field of physical time, or that of a gravitational field.

Notice as the energy or mass relationships change so, also, does the gravitational field intensity. Were our moon to have an increase of heat energy within (E), then the gravitational field would increase. Were our moon to retain its heat energy, but the mass of it were to decrease in proportion to the energy, then the gravitational field would also increase. Were our moon to have no heat energy within, then it would have no gravitational field.

Our planet expends 0.00444 kg. of mass in form of gravitational waves every second in order for all things to remains where they should be. Our sun expends 665 lbs. a second in order for the planets to remain in place.

http://360.yahoo.com/noddarc there is a short writing entitled "Magnetism and Gravity." It is short and easy to read. It may be of interest.