Force of gravity and tides in conjunction

Storyboard

Gravity and centrifugal acceleration generate tides, the movement of oceans that raises and lowers their level with a frequency of 12 hours. Their origin can be generated by both the moon and the sun.

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ID:(1523, 0)



Mechanisms

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Concept

Mechanisms

ID:(15439, 0)



Variation of gravity perpendicular to the radius, in conjunction

Image

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There is a contribution from the gravitational attraction of the celestial body that pulls water towards the equatorial region:



The hypotenuse of the triangle is related to the vertical leg by:

$R\sin\theta$



and the horizontal leg by:

$d - R\cos\theta$



Using the Pythagorean theorem, we have:

$R^2\sin^2\theta+(d-R\cos\theta)^2=d^2+R^2-2Rd\cos\theta$

ID:(11635, 0)



Variation of gravity parallel to the radius, in conjunction

Image

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There is a contribution from the gravitational attraction of the celestial body that pulls water towards the radius, which tends to displace the water towards the equatorial zone:



The hypotenuse of the triangle is formed by the vertical leg:

$R\sin\theta$



and the horizontal leg:

$d - R\cos\theta$



According to the Pythagorean theorem, we have:

$R^2\sin^2\theta+(d-R\cos\theta)^2=d^2+R^2-2Rd\cos\theta$

ID:(11658, 0)



Model

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Parameters

Symbol
Text
Variable
Value
Units
Calculate
MKS Value
MKS Units
$a_c$
a_c
Acceleration generated by the celestial body, en conjunction
m/s^2
$\Delta a_{cx}$
Da_cx
Acceleration variation parallel to the ecliptic, in conyunction
m/s^2
$\Delta a_{cy}$
Da_cy
Acceleration variation perpendicular to the ecliptic
m/s^2
$\theta$
theta
Angle from the planet line - celestial object
rad
$d$
d
Celestial object planet distance
m
$M$
M
Masa del cuerpo que genera la marea
kg
$R$
R
Planet radio
m
$G$
G
Universal Gravitation Constant
m^3/kg s^2

Variables

Symbol
Text
Variable
Value
Units
Calculate
MKS Value
MKS Units

Calculations


First, select the equation: to , then, select the variable: to

Calculations

Symbol
Equation
Solved
Translated

Calculations

Symbol
Equation
Solved
Translated

Variable Given Calculate Target : Equation To be used




Equations

#
Equation

$ a_c = \displaystyle\frac{ G M }{ d ^2+ R ^2-2 d R \cos \theta }$

a_c = G * M /( d ^2+ R ^2-2* d * R *cos( theta ))


$ \displaystyle\frac{ \Delta a_{cx} }{ a_c } =\displaystyle\frac{ d - R\cos\theta }{ \sqrt{ d ^2+ R ^2-2 d R \cos \theta } }$

Da_cx / a_c = ( d - R * cos( theta ))/sqrt( d ^2 + R ^2 - 2 * d * R * cos( theta ))


$ \Delta a_{cx} = \displaystyle\frac{ G M }{ d ^2}\left(1+\displaystyle\frac{2 R \cos \theta }{ d }\right)$

Da_cx = G * M *(1 + 2* R * cos( theta )/ d )/ d ^2


$ \displaystyle\frac{ \Delta a_{cy} }{ a_c } =\displaystyle\frac{ R\sin\theta }{ \sqrt{ d ^2+ R ^2-2 d R \cos \theta } }$

Da_cy / a_c = R * sin( theta ) / sqrt( d ^2 + R ^2 - 2 * d * R * cos( theta ))


$ \Delta a_{cy} = \displaystyle\frac{ G M }{ d ^2 }\displaystyle\frac{ R \sin \theta }{ d }$

Da_cy = G * M * R * sin( theta )/ d ^3

ID:(15434, 0)



Variation of acceleration perpendicular to the radius, in conjunction

Equation

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To determine the variation of the acceleration perpendicular to the radius, we can use triangle similarity to equate the relation

$\displaystyle\frac{\Delta a_{cy}}{a_c}$



with the length

$d-R\cos\theta$



and the hypotenuse

$\sqrt{d^2+R^2-2dR\cos\theta}$

.

By triangle similarity, we have with that

$ \displaystyle\frac{ \Delta a_{cy} }{ a_c } =\displaystyle\frac{ R\sin\theta }{ \sqrt{ d ^2+ R ^2-2 d R \cos \theta } }$

$a_c$
Acceleration generated by the celestial body, en conjunction
$m/s^2$
8572
$\Delta a_{cy}$
Acceleration variation perpendicular to the ecliptic
$m/s^2$
8576
$\theta$
Angle from the planet line - celestial object
$rad$
8569
$d$
Celestial object planet distance
$m$
8567
$R$
Planet radio
$m$
8566

.

ID:(11643, 0)



Acceleration perpendicular to the radius, in conjunction

Equation

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Con la ley de la gravitación de Newton, con , es:

$ F = G \displaystyle\frac{ m_g M }{ r ^2}$



Se puede, con la definición de la fuerza, con :

$ F = m_i a $



Y el radio al cuadrado:

$r^2=d^2+R^2-2dR\cos\theta$



Calcular la aceleración reemplazando el radio en la fuerza y despejando la aceleración. Esto da con la aceleración:

$ a_c = \displaystyle\frac{ G M }{ d ^2+ R ^2-2 d R \cos \theta }$

$a_c$
Acceleration generated by the celestial body, en conjunction
$m/s^2$
8572
$\theta$
Angle from the planet line - celestial object
$rad$
8569
$d$
Celestial object planet distance
$m$
8567
$M$
Masa del cuerpo que genera la marea
$kg$
8568
$R$
Planet radio
$m$
8566
$G$
Universal Gravitation Constant
$m^3/kg s^2$
8564

ID:(11644, 0)



Acceleration approximation perpendicular to the radius, in conjunction

Equation

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With acceleration generated by the celestial body, en conjunction $m/s^2$, acceleration variation perpendicular to the ecliptic $m/s^2$, angle from the planet line - celestial object $rad$, celestial object planet distance $m$ and planet radio $m$, the relationship between the variation of acceleration and acceleration is:

$ \displaystyle\frac{ \Delta a_{cy} }{ a_c } =\displaystyle\frac{ R\sin\theta }{ \sqrt{ d ^2+ R ^2-2 d R \cos \theta } }$



And since the expression for acceleration is with acceleration generated by the celestial body, en conjunction $m/s^2$, angle from the planet line - celestial object $rad$, celestial object planet distance $m$, masa del cuerpo que genera la marea $kg$, planet radio $m$ and universal Gravitation Constant $m^3/kg s^2$:

$ a_c = \displaystyle\frac{ G M }{ d ^2+ R ^2-2 d R \cos \theta }$



It follows that:

$\Delta a_{cy} = GM\displaystyle\frac{R\sin\theta}{(d^2 + R^2 - 2dR\cos\theta)^{3/2}}\sim \displaystyle\frac{GM}{d^2}\displaystyle\frac{R\sin\theta}{d}$



Therefore, in the approximation d\gg R, we can approximate with by:

$ \Delta a_{cy} = \displaystyle\frac{ G M }{ d ^2 }\displaystyle\frac{ R \sin \theta }{ d }$

$\Delta a_{cy}$
Acceleration variation perpendicular to the ecliptic
$m/s^2$
8576
$\theta$
Angle from the planet line - celestial object
$rad$
8569
$d$
Celestial object planet distance
$m$
8567
$M$
Masa del cuerpo que genera la marea
$kg$
8568
$R$
Planet radio
$m$
8566
$G$
Universal Gravitation Constant
$m^3/kg s^2$
8564

ID:(11645, 0)



Acceleration variation parallel to the radius, in conjunction

Equation

>Top, >Model


To determine the variation of the acceleration parallel to the radius, we can use triangle similarity to equate the relation

$\displaystyle\frac{\Delta a_{cx}}{a_c}$



with the length

$d+R\cos\theta$



and the hypotenuse

$\sqrt{d^2+R^2-2dR\cos\theta}$



By triangle similarity, we have with that

$ \displaystyle\frac{ \Delta a_{cx} }{ a_c } =\displaystyle\frac{ d - R\cos\theta }{ \sqrt{ d ^2+ R ^2-2 d R \cos \theta } }$

$a_c$
Acceleration generated by the celestial body, en conjunction
$m/s^2$
8572
$\Delta a_{cx}$
Acceleration variation parallel to the ecliptic, in conyunction
$m/s^2$
8575
$\theta$
Angle from the planet line - celestial object
$rad$
8569
$d$
Celestial object planet distance
$m$
8567
$R$
Planet radio
$m$
8566

ID:(11647, 0)



Approach acceleration parallel to the radius, in conjunction

Equation

>Top, >Model


With acceleration generated by the celestial body, en conjunction $m/s^2$, acceleration variation parallel to the ecliptic, in conyunction $m/s^2$, angle from the planet line - celestial object $rad$, celestial object planet distance $m$ and planet radio $m$, the relationship is:

$ \displaystyle\frac{ \Delta a_{cx} }{ a_c } =\displaystyle\frac{ d - R\cos\theta }{ \sqrt{ d ^2+ R ^2-2 d R \cos \theta } }$



And as for acceleration generated by the celestial body, en conjunction $m/s^2$, angle from the planet line - celestial object $rad$, celestial object planet distance $m$, masa del cuerpo que genera la marea $kg$, planet radio $m$ and universal Gravitation Constant $m^3/kg s^2$,

$ a_c = \displaystyle\frac{ G M }{ d ^2+ R ^2-2 d R \cos \theta }$



Thus, we have:

$\Delta a_{cx} =GM\displaystyle\frac{d - R\cos\theta}{(d^2 + R^2 - 2dR\cos\theta)^{3/2}}\sim \displaystyle\frac{GM}{d^2}\left(1+\displaystyle\frac{2R\cos\theta}{d}\right)$



Therefore, in the approximation d\gg R, we can approximate with by:

$ \Delta a_{cx} = \displaystyle\frac{ G M }{ d ^2}\left(1+\displaystyle\frac{2 R \cos \theta }{ d }\right)$

$\Delta a_{cx}$
Acceleration variation parallel to the ecliptic, in conyunction
$m/s^2$
8575
$\theta$
Angle from the planet line - celestial object
$rad$
8569
$d$
Celestial object planet distance
$m$
8567
$M$
Masa del cuerpo que genera la marea
$kg$
8568
$R$
Planet radio
$m$
8566
$G$
Universal Gravitation Constant
$m^3/kg s^2$
8564

ID:(11650, 0)