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I think that the rate would be the same on moon and earth. i was thinking it had something to do with the universal law of gravitation, but i think i am off track. can someone please help me?

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I think that the rate would be the same on moon and earth. i was thinking it had something to do with the universal law of gravitation, but i think i am off track. can someone please help me?

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Kurdt

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Kurdt

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[tex] F = ma [/tex] and [tex] F=G\frac{mM}{r^2} [/tex]

It is not true to say that the moon has no gravity. The moon exerts a gravitational force on an object because it has mass like the Earth.

Have you seen the second equation before?

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Kurdt

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Ok. The second equation is the universal law of gravitation. It is the force between two objects one of mass m and another of mass M separated by distance r. G is just a constant. So if this second equation is the force between two objects consider the following.

Say the Earth was mass M

Then do the same for the moon with mass M

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Just to add on what the units are-Ok. The second equation is the universal law of gravitation. It is the force between two objects one of mass m and another of mass M separated by distance r. G is just a constant. So if this second equation is the force between two objects consider the following. ?

[tex] F=G\frac{mM}{r^2} [/tex]

G = 6.67300 × 10-11

M or m = mass measured in kilograms

R = Distance from center in meters

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Kurdt

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If you want to state what the units are then G has units of mJust to add on what the units are-

[tex] F=G\frac{mM}{r^2} [/tex]

G = 6.67300 × 10-11

M or m = mass measured in kilograms

R = Distance from center in meters

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woops, forgot that Also the outcome force is measured in newtons.If you want to state what the units are then G has units of m^{3}kg^{-1}s^{-2}

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M = a??? Your saying mass = acceleration?? Thats not correct.

You are right that acceleration is greater here on earth than the moon, though.

If you really want to know acceleration caused by a mass then use the equation-

[tex] F=G\frac{M}{r^2} [/tex]

units are the same but the outcome is m/s instead of newtons.

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You are almost correct. With the highlighted equation you can easily obtain acceleration by cancelling the mass of the falling object to give.

[tex] a=G \frac{M}{r^2} [/tex]

As you correctly deduced the rate of falling on the moon and Earth will therefore be different because the masses of the Earth and Moon are different.

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Kurdt

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That is the acceleration due to gravity not the force as you have implied with your notation.If you really want to know acceleration caused by a mass then use the equation-

[tex] F=G\frac{M}{r^2} [/tex]

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What are you talking about?? Of course its due to gravity, i don't know what your implying.That is the acceleration due to gravity not the force as you have implied with your notation.

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[tex] a=G\frac{M}{r^2} [/tex]

The earth has a mass of 5.9742*10^24 kilograms. The radius of the earth is 6378100 meters. Of course G is 6.67*10^-11. So plugging that in you have

[tex] a=6.67*10-11\frac{5.9742*10^24}{6378100^2} [/tex]

So here we see that acceleration here is 9.8m/s which is the true acceleration of gravity on earth.

Since i did the earth try doing the moon.

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He's implying that it should have been a = GM/r^2, not F = GM/r^2.What are you talking about?? Of course its due to gravity, i don't know what your implying.

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Kurdt

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I was saying your notation implied force was given by that equation which it is not. Its acceleration that is given by that equation just as Mace has replied.What are you talking about?? Of course its due to gravity, i don't know what your implying.

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