Eclipse and the Accelleration of the Earth ?

[Bjarne]

So soon the moon moves between the Sun and the Earth, by eclipse, - and the 3 objects will be aligned, - how fast can the Earth possible accelerate due to that ?

And how can it be calculated ?

 

 

[swansont]

Newton's law of gravitation should suffice.

[Bjarne]

^{Newton's law of gravitation should suffice.}

 

^{Is it so simple that I only need to add the acceleration due to gravity of the Moon (based on MG/r^2)}

^{7,35E22*6,67@E-11/384000000^2 = 0,000033 m/s^2}

 

^{I think not, it must be calculated from the common gravitational centre (near the center of the Sun) right =?}

[swansont]

It's a vector, so the two contributions add as vectors.

[Strange]

In fact, it seems to be the easiest point in time to calculate the combined effect of the two on the Earth as the two vectors will be aligned so you can simply add the two forces. At any other point, you will have to take into account the angle between the two vectors.

[imatfaal]

In fact, it seems to be the easiest point in time to calculate the combined effect of the two on the Earth as the two vectors will be aligned so you can simply add the two forces. At any other point, you will have to take into account the angle between the two vectors.

 

One of the two easiest places

[Strange]

One of the two easiest places

 

Unless you find subtraction harder than addition.

[Janus]

Unless you find subtraction harder than addition.

In which case you can just convert to 10's complement and subtract by adding.

Edited September 27, 2013 by Janus

[Ophiolite]

The division on this point seems to have multiplied the responses.

[michel123456]

IIRC an eclipse is not seen as such from everywhere on the globe. In order to get perfect alignment you need a very specific eclipse.

 

And IIRC it is the Earth-Moon system that is orbiting the Sun, anyway.

 

You can call me IIRC.

[Bjarne]

In fact, it seems to be the easiest point in time to calculate the combined effect of the two on the Earth as the two vectors will be aligned so you can simply add the two forces. At any other point, you will have to take into account the angle between the two vectors.

 

Let’s say that the angle from a point between the Earth and Moon is 90 degree, - and the angle from the same point on Earth to the Sun zero degree.

 

To keep it simple let’s say that the acceleration due to gravity against the Sun and the Moon is the same acceleration

 

What still confuses me is that according to Newton’s second law (so far as I understand it) the resulting force will point between the two forces, which only mean only change of direction and therefore no change of force acting on the Earth so far.

 

On the other hand there is no doubt that so soon the Eaeth/Moon/Sun alignment is completed (total eclipse) then 2 forces must have united , and therefore double so strong

 

But where does the unification of the 2 forces start ?

Does the 2 force already start to unite after the angle between the 2 forces (Sun and Moon) begins to decrease to less as 90 degree relative to a point on Earth?

Or first when the eclipse starts ?

 

I am lost

Edited December 31, 2013 by Bjarne

[swansont]

 

Let’s say that the angle from a point between the Earth and Moon is 90 degree, - and the angle from the same point on Earth to the Sun zero degree.

 

To keep it simple let’s say that the acceleration due to gravity against the Sun and the Moon is the same

 

What still confuses me is that according to Newton’s second law (so far as I understand it) the resulting force will point between the two forces, which only mean only change of direction and therefore still the same

 

 

That's not how you add vectors. The resultant at 90 degrees will follow the Pythagorean theorem. c² = a² + b²

 

0.000042 in this case.

[Bjarne]

 

That's not how you add vectors. The resultant at 90 degrees will follow the Pythagorean theorem. c² = a² + b²

 

0.000042 in this case.

Thank you what then is the angle is 45 degree and 10 degree ?

[swansont]

http://www.mathwarehouse.com/vectors/resultant-vector.php