✔ 最佳答案
Q: Why is the Coriolis effect equal to zero at the equator and maximum at the poles?
A: Coriolis force (which is a fictitious force) arises because of inertia in a rotational system in which the object in question must have a motion (i.e. possesses velocity). In the situation of the earth, the motion must be along a longitude, or have a velocity component along the longitude ( i.e. across the latitudes).
Hence, if the object moves along the equator, there is no Coriolis force arisen.
Likewise, if the object is motionless at the pole, no Coriolis force is observed. Coriolis force only arises when the object moves away from the equator or the poles.
Q2: Why can we use that law to explain an object with uniform motion?
A: For example, when an object moves northward from the equator, it revolves at a circle of smaller radius. As such, the moment of inertia of the object about the earth axis tends to decrease. In order for angular momentum to be conserved, the speed of the object in the rotational direction of the earth would be increased.
For the same argument, if an object moves southward from the north-pole, its moment if inertia about the earth axis tends to increases because the object revolves with the earth in a circle of larger radius. Hence, for angular momentum of the object to be conserved, the object must moves at a slower speed relative to the rotation of the earth..
2012-11-18 16:45:03 補充：
Your suppl question: if an object move northeasternly at the equator, v is not parallel to w then will there be any coriolis effect?
A: If the object moves north-easternly from the equator, the north moving component gives rise to a Coriolis force, which deflects the object towards the east....
2012-11-18 16:50:08 補充：
The easterly velocity component doesn't lead to any Coriolis force. As a result, the object will be deflected more towards the east.
