# Search results

1. ### Mass distribution and gravitational field

I return to the topic after a long time ... A tangible example, the moon will not be a celestial body in perfect spherical symmetry. How this affect on its motion around the earth? thanks
2. ### Mass distribution and gravitational field

Thank you, questions: what effects on the general motion of the earth are due to its non-spherical symmetry? astrophysicists will take account of this.... Even artificial satellites are definitely not spherically symmetric objects (although relatively small): as we can account for this?
3. ### Mass distribution and gravitational field

The field outside a body with spherical mass distribution is well known but for a non simmetrical body (or a almost simmetrical body like the earth) which is the approach?. Do you know any reference? thank you
4. ### 3.6 + 4.4 + 5.8 = 13.8

just a simple question: having to round up the following numbers: 3.6 + 4.4 + 5.8 = 13.8 I could do this: 4.0 + 4.0 + 6.0 = 14.0 but wanting to keep the sum?
5. ### Cosmic rays

most of the cosmic rays that hit the earth is made up of positively charged particles, like protons. This suggests that the earth has a growing excess of positive charge .... Is this true?
6. ### Magnetic forces

May be a trivial question.... The forces that arise from the magnetic field are Lorentz forces that not make mechanical work. When a piece of iron is attracted by a magnet is accelerated and its kinetic energy increases: Who does the work necessary?
7. ### Action and reaction

But the law of action/reaction indicates a precise direction and versus of the total force on the body. It seems there was also a point of application...or not? Which is the meaning of this?
8. ### Action and reaction

In a generic case of a mass point and an extended body to interact with gravitational force, the total force on the point admits a reaction to be construed as, on the extended body ? The total force on the extended body do not arise from the interaction between two points, but between a...
9. ### Gravitational force

thank you, Have you reference? Where can I found the calculus?
10. ### Gravitational force

Hi, it is well know that the force on a mass point outside to an homogeneous sphere is as the whole sphere's mass is concentred on its centre. It seems that the reaction of this force (the total force of the point on the shepre) is applied on the centre of the sphere but, is it true? If this...