Lecture

Foucault Pendulum: Newtonian Physics and Rotating Reference Frames

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Description

This lecture explores the physics of a simple pendulum in both an absolute and a rotating reference frame, highlighting the differences in the equations of motion and the introduction of pseudo-forces to account for the rotation. The instructor demonstrates how the pendulum's oscillation plane deviates when viewed from a rotating disc, emphasizing the importance of choosing the correct reference frame for accurate analysis.

Official source

Ontological neighbourhood

Physics

Mechanics: Classical mechanics

Related concepts (15)

Centrifugal force

In Newtonian mechanics, the centrifugal force is an inertial force (also called a "fictitious" or "pseudo" force) that appears to act on all objects when viewed in a rotating frame of reference. It is directed away from an axis which is parallel to the axis of rotation and passing through the coordinate system's origin. If the axis of rotation passes through the coordinate system's origin, the centrifugal force is directed radially outwards from that axis.

Rotating reference frame

A rotating frame of reference is a special case of a non-inertial reference frame that is rotating relative to an inertial reference frame. An everyday example of a rotating reference frame is the surface of the Earth. (This article considers only frames rotating about a fixed axis. For more general rotations, see Euler angles.) Fictitious force All non-inertial reference frames exhibit fictitious forces; rotating reference frames are characterized by three: the centrifugal force, the Coriolis force, and, for non-uniformly rotating reference frames, the Euler force.

Non-inertial reference frame

A non-inertial reference frame is a frame of reference that undergoes acceleration with respect to an inertial frame. An accelerometer at rest in a non-inertial frame will, in general, detect a non-zero acceleration. While the laws of motion are the same in all inertial frames, in non-inertial frames, they vary from frame to frame depending on the acceleration. In classical mechanics it is often possible to explain the motion of bodies in non-inertial reference frames by introducing additional fictitious forces (also called inertial forces, pseudo-forces and d'Alembert forces) to Newton's second law.

Pendulum

A pendulum is a weight suspended from a pivot so that it can swing freely. When a pendulum is displaced sideways from its resting, equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the equilibrium position. When released, the restoring force acting on the pendulum's mass causes it to oscillate about the equilibrium position, swinging back and forth. The time for one complete cycle, a left swing and a right swing, is called the period.

Equations of motion

In physics, equations of motion are equations that describe the behavior of a physical system in terms of its motion as a function of time. More specifically, the equations of motion describe the behavior of a physical system as a set of mathematical functions in terms of dynamic variables. These variables are usually spatial coordinates and time, but may include momentum components. The most general choice are generalized coordinates which can be any convenient variables characteristic of the physical system.

Related lectures (64)

Inertial Forces and Reference Frames

Explores inertial forces, reference frames, Newton's laws, and apparent weight in an accelerated elevator.

Mechanics: Inertial and Non-Inertial Frames

Explores mechanics in inertial and non-inertial frames, covering forces, Coriolis effect, and Poisson formula.

Uniform Rectilinear Motion: Carousel

Explores uniform rectilinear motion on a carousel, including coriolis force and inertial forces.

Forces in Accelerated Frames

Explores mechanics in accelerated frames, emphasizing inertial forces and their effects on motion.

Mechanics: Equilibrium Points and Stability