The Coriolis force is the cause, while Ferrel's Law is the effect or description of that effect. Ferrel's Law describes the deflection of moving objects (like wind and ocean currents) on Earth due to the Coriolis force.
Here's a breakdown:
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Coriolis Force:
- An apparent force resulting from the Earth's rotation. It's not a real force in the Newtonian sense, but rather an effect observed from a rotating frame of reference (like being on Earth).
- Acts perpendicular to the direction of motion of an object.
- Its magnitude depends on the object's velocity and the latitude.
- Is strongest at the poles and nonexistent at the equator.
- Simply put, it's why things deflect.
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Ferrel's Law:
- A description of the effect of the Coriolis force.
- States that in the Northern Hemisphere, moving objects are deflected to the right of their intended path, and in the Southern Hemisphere, they are deflected to the left.
- Applies primarily to large-scale movements like wind and ocean currents.
- Ferrel's Law describes what happens as a result of the Coriolis Force.
| Feature | Coriolis Force | Ferrel's Law |
|---|---|---|
| Nature | Apparent force | Description of an effect |
| Role | Cause | Effect |
| Definition | An apparent force caused by the Earth's rotation that deflects moving objects. | Describes the deflection of moving objects due to the Coriolis force (right in NH, left in SH). |
| Application | Applicable to any moving object on Earth, but most noticeable with large-scale movements. | Primarily applied to wind and ocean currents, large-scale atmospheric and oceanic phenomena. |
In essence, you can think of the Coriolis force as the physics explanation, and Ferrel's Law as a simplified rule of thumb describing the outcome of that physics. Ferrel's Law describes what we observe due to the why of the Coriolis force.
