Does the sun or the moon have a greater affect on the tides?

In summary, the tides are caused by the variation in the force of gravity, which can be calculated using the equation F = GMm/r2 and its spatial derivative. This results in a 1/r3 term in the equation for tides.
  • #1
Vitani11
275
3

Homework Statement



I know the moon does. I know it is because tidal forces fall off as 1/r3. But why? Mathematically, I mean.

Homework Equations


F = GMm/r2

The Attempt at a Solution


None
 
Physics news on Phys.org
  • #2
Vitani11 said:
I know the moon does. I know it is because tidal forces fall off as 1/r3. But why? Mathematically, I mean.
In what way does this statement not contain both the question and the answer?
 
  • #3
I should have been more specific. How do you get from F = GMm/r2 to an equation for tides that has a 1/r3 in it?
 
  • #4
Vitani11 said:
I should have been more specific. How do you get from F = GMm/r2 to an equation for tides that has a 1/r3 in it?
Did you try a search on Tidal Force? Even the Wikipedia article on Tidal Force shows a short derivation (granted it's for the locations lying along the line joining the centers of the two interacting bodies, but it avoids the vector math required for the more general solution for points located anywhere on the surface of the smaller body).
 
  • #5
Vitani11 said:
I should have been more specific. How do you get from F = GMm/r2 to an equation for tides that has a 1/r3 in it?

Tides result because of the variation of the force of gravity. Points on the side of the Earth near to the moon are more strongly attracted than points on the far side.

In other words, the tides are not caused by the force of gravity which is proportional to 1/r2 but rather by the variation in that force over a distance the size of the earth, that is to say the spatial derivative . And the derivative of 1/r2 is ...
 

FAQ: Does the sun or the moon have a greater affect on the tides?

1. Does the sun or the moon have a greater effect on the tides?

The moon has a greater effect on the tides due to its closer proximity to Earth and its stronger gravitational pull.

2. How does the sun's position affect tides?

The sun's position does have an impact on tides, but it is not as significant as the moon's. When the sun and moon align, their gravitational forces combine, resulting in higher high tides and lower low tides, known as spring tides.

3. Why do we have two high tides and two low tides each day?

The Earth rotates through two tidal bulges created by the gravitational pull of the moon and sun. As a result, any given location experiences two high tides and two low tides each day.

4. How do the moon phases affect tides?

During a full moon or new moon, the sun, moon, and Earth are aligned, resulting in the strongest gravitational pull and the highest high tides and lowest low tides, known as spring tides. Quarter moons create neap tides, which are weaker due to the sun and moon's gravitational forces working against each other.

5. Is there a difference in tides between the side of Earth facing the moon and the opposite side?

Yes, the side of Earth facing the moon experiences the highest high tides and lowest low tides, while the opposite side experiences the lowest high tides and highest low tides. This is due to the moon's gravitational pull being stronger on the side facing it.

Similar threads

Back
Top