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Name: Unknown
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: Around 1993


Question:
Does Centrifugal force really exist? If not, then why do so many people use it to explain everyday occurrences? For example, when you swing a bucket of water around, what keeps the water in? Most people would say centrifugal force.



Replies:
Yes, this idea does have a sound meaning and valid existence. It does not represent a "real" force in the sense that Newton uses, which is: something that gives rise to accelerations in a reference frame which is not rotating or being accelerated (a frame in which objects at rest tend to stay at rest unless acted on by a force) (these frames are called inertial frames). However, in a rotating reference frame (or coordinate system) such as a merry go round, objects that are at rest tend to slide and objects with no "real" force do not move in straight lines. Have you ever tipped over a glass full of liquid in a turning car? From the point of view of the rotating coordinate system what tipped the glass over is the "centrifugal force". From the point of view of the inertial frame of reference outside the car, the glass was still trying to go forward in a straight line when the car turned and the force acting on the bottom of the cup flipped it over. Both perspectives are valid and you can calculate the results from both perspectives as dictated by convenience, but there is no "real" force of this type. It is however very useful to think this way.

Sam Bowen



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