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Q & A: 'Acceleration' due to gravity

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Most recent answer: 11/17/2014
Q:
Why is it said that we and all objects on the Earth are "accelerated" towards the Earth by it's gravitational field, even if we nor the objects are moving towards it at all?
- Kyle (age 21)
California
A:

Hi Kyle,

Acceleration of a body is proportional to the sum of all the forces.  When you are standing still on the ground there two forces involved, that of gravity pushing you down and that of the ground pushing you up.  They are equal and opposite so they cancel out and you don't accelerate.   However if you jump off of a roof there is no ground force and so you will indeed accelerate downward at the usual rate,   32 feet per second per second.

 

LeeH


(published on 11/17/2014)

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