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My Physics teacher stated that Pluto has a gravitational pull on objects on Earth, namely humans. Is this true? What is the free-fall acceleration of Pluto with respect to being on the Earth's surface? (i.e. the Earth's free-fall acceleration is 9.8 m/s*s).

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This is true. Newton's law of universal gravitation says everything attracts everything. To get the free-fall acceleration of some object on Earth towards Pluto, take Newton's law and divide by the object's mass to get $$a=\frac{F}{m}=\frac{GM}{r^2}.$$ Subbing in reasonable values - $M=0.002$ Earth masses, and $r$ between 29 and 49 AU you get something like $10^{-14}\textrm{ m s}^{-2}$.

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Next step: compare this to the gravitational attraction between you and that cute member of the apposite sex on the other side of the classroom... –  dmckee Apr 24 '12 at 1:25
ah! but the attraction between me and Pluto is symmetric, whereas... –  Emilio Pisanty Apr 24 '12 at 1:28
Thank you so much! –  zzg Apr 24 '12 at 21:41
@dmckee $G (70 kg) / (3 m)^2 = 5 \times 10^{-11} m s^{-2}$, so the attraction is five thousand times greater. –  AlanSE Sep 18 '12 at 14:30
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I am not a physicist but this will answer your query; According to Newton's law of universal gravitation every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.


for example: lets say r is the distance between earth and pluto, G the universal gravitation constant, m1 is the mass of pluto and m2 be the mass of a human on earth, we can then calculate the gravitational force exerted by m1 to m2.

you can also refer this site http://www.physicsclassroom.com/class/circles/u6l3c.cfm

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