What is the formula to calculate the gravity on the moon ?

Question

to calculate gravity on earth you use the formula Fz = M×10 ( mass × 10 ) so whitch formula you use to calculate the gravity on the moon ?

Answer 1

A better formula for gravity on the Earth is:

Fg=m(9.8 m/sec^2) where m is the mass of the object.

Your formula is rounded off, which is okay, but with 9.8 m/sec^2 being a known constant, it's easier to see how the equation has to be modified for the Moon. 9.8 m/sec^2 is the acceleration due to gravity on the surface of the Earth. It comes from the formula:

Fg=(G M1 m2)/r^2

The G is the universal gravitational constant of 6.67 x 10^(-11) m^3 sec^2/kg

M1 is the mass of the Earth (5.97 x 10^24 kg)

At the surface of the Earth, your distance from the center of Earth is equal to the Earth's radius (app 6,378,000 meters)

None of those three values change, so the math on them is done ahead of time leaving you with a constant times whatever the mass of the object is.

Two things change if you want the gravity on the Moon.

The mass of the Moon is 73.5 x 10^21 kg.
The radius of the Moon is 1,738,000 meters.

Plug those into your equation for the force of gravity:

Fg = (G M1)/r^2 * m2

And, yes, the force of gravity is about 1/6 as strong as it is on the Earth's surface.

Edit: Let me add one thing about the problem of using 10 for acceleration due to gravity. You're using a constant with only 1 significant digit, so, technically, your final answer should be rounded off to 1 significant digit, which will be a problem when you try dividing 10 by 6. Then again, if you're using 10 as acceleration, you might not be maintaining some stringent adherence to significant digits, either.

Answer 2

Acceleration Due To Gravity Formula

Answer 3

F = G *M1*M2/R^2

Substitute the mass of the moon for the mass of the Earth (the other mass is your reference mass and does not change); change the radius of the Moon for the radius of the Earth.

I an save you a lot of calculations though. Gravity on the surface of the Moon is about 1/6 of one G.

Answer 4

You said "Fz = M×10". You may be still studying in school, because I've seen that kids say the same formula above.

But the correct formula is:
Gravitational force acting on a body of mass m is
  F = m×g
where g = 9.80665 (this value is written as '10' in your text book).

Now this value of g = 9.8 or 10 is applicable for earth.
In the case of moon, you need to have a new value for g.

The value for g of moon is 1.63. This value is approximately 1/6th of value of g of earth.

So the formula to calculate gravitational force on moon would be
  F=m×1.63
or, to be compliant with your text book, it can be written as:
       M×10
F = ---------
           6

If you're curious to know more about the value of g for moon, check out pages I list as sources.
_______
Viva La Dvorak! - www.dvzine.org

Answer 5

You use the same formula that you would on Earth. Except for the moon you use the mass of the moon and the radius of the moon at it's surface.

Answer 6

You know Newton's famous formula:
F=ma

In order to calculate weight of a mass (which is a force) on earth you substitute 9.86m/s^2 in the formula: F=9.86*m

9.86 m/s^2 is accelaration of free falling mass on earth. Now you need the accelaration of free falling mass on moon:

a=G*Mm/R^2

G: Gravitational Constant (6.6742*10^(-11))
Mm: Mass of Moon
R: Distance from center of moon (for short falls it is reasonable to consider it as the radius of moon)

After substitution, it can be calculated:
a=1.57m/s^2

Finally for calculating weight of a body on eart you can use the following formula:

F=1.57*m
(m is the mass of body)

Answer 7

I actaully dont know who are you like some kind of scientist? i think thats cr azy i dont think i would ever be able to figure that out.