Centrifugal Force In Newtonian Mechanics

1438 Words null Page
In Newtonian mechanics, the term centrifugal force is used to refer to an inertial force (also called a 'fictitious ' force) directed away from the axis of rotation that appears to act on all objects when viewed in a rotating reference frame.

The concept of centrifugal force can be applied in rotating devices such as centrifuges, centrifugal pumps, centrifugal governors, centrifugal clutches, etc., as well as in centrifugal railways, planetary orbits, banked curves, etc. when they are analyzed in a rotating coordinate system.

The name has historically sometimes also been used to refer to the reaction force to the centripetal force.

Centrifugal force is an outward force apparent in a rotating reference frame; it does not exist when measurements
…show more content…
Together, these three fictitious forces are necessary for the formulation of correct equations of motion in a rotating reference frame and allow Newton 's Laws to be used in their normal form in such a frame.
Consider a stone being whirled round on a string. The only real force acting on the stone is the tension in the string. There are no other forces acting on the stone so there is a net force on the stone.

In an inertial frame of reference, were it not for this net force acting on the stone, the stone would travel in a straight line, according to Newton 's first law of motion. In order to keep the stone moving in a circular path, this force, known as the centripetal force, must be continuously applied to the stone. As soon as it is removed (for example if the string breaks) the stone moves in a straight line. In this inertial frame, the concept of centrifugal force is not required as all motion can be properly described using only real forces and Newton 's laws of
…show more content…
However, the object is moving in a circular path as the Earth rotates.

When considered in an inertial frame (that is to say, one that is not rotating with the Earth), some of the force of gravity is expended just to keep the object in its circular path (centripetal force). As such, less tension in the spring is required to counteract the 'remaining ' force of gravity. Less tension in the spring would be reflected on a scale as less weight - for this reason the object will weigh about 0.5% less at the equator than at the poles. The concept of centrifugal force is not required.

However, it is generally more convenient to take measurements in a frame of reference rotating with the Earth. In this reference frame the object is stationary and to account for the loss in measured weight when the object is measured at the equator it is necessary to include the upward acting (inertial or fictitious) centrifugal force. In practice, this is often observed as a reduction in the force of gravity.

An equatorial railway
This thought experiment is more complicated than the previous two examples in that it requires the use of the Coriolis force as well as the centrifugal

Related Documents