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Q & A: Would your weight decrease closer to the center of the earth?

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Most recent answer: 09/22/2014
Q:
A person standing on the surface of the earth weighs X lbs. Lets ignore any gravitational anomalies such as mass-cons. If the person were able to move toward the center of the earth would their weight decrease as they progressed toward the center? Thanks in advance.
- Alvin (age 61)
Minneapolis, MN USA
A:

Yes! Your weight would decrease as you moved towards the center of the earth. Only the part of the Earth that's closer to the center than you are contributes to your weight. As you move towards the center, there is less and less of the Earth closer to the center than you are, so the gravitational field gets weaker and your weight decreases. (Your mass, however, stays the same.) In general, gravity also gets stronger as you get closer to the center of a massive object, but it turns out that the effect of having less mass closer to the center than you are is more important. At the exact center of the Earth, the gravitational field is actually zero. This can all be shown with some calculus.

You might be interested in these other Q&As on similar questions: , , and . Also, considers what would happen if you dropped a ball into a hole that passes all the way through the center of the earth and out the other side.

Rebecca Holmes


(published on 09/22/2014)

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