Published March 2011 | Version v1
Journal article

Rules for rolling as a rotation about the instantaneous point of contact

  • 1. IMFUFA, Department of Sciences, Roskilde University, DK-4000 Roskilde (Denmark)

Description

It is a widespread misunderstanding in introductory physics courses that the motion of rolling bodies in general can be calculated using the point of contact as a reference point when equating the rate of change of angular momentum to the torque. In this paper I discuss in general two correct rules to be used instead, in order to derive the equation of motion of rolling bodies, taking moments about the point of contact. I also clarify that the point of contact either can be reckoned the fixed point on the rolling body instantly at the point of contact or the geometrical point defined as the point of contact at any time. Altogether this gives four different ways of deriving the equation of motion with some of them being easier than others depending on the case under consideration. The four different methods are as an illustration applied to a case presented recently by Turner and Turner (2010 Am. J. Phys. 78 905-7).

Availability note (English)

Available from http://dx.doi.org/10.1088/0143-0807/32/2/012

Additional details

Identifiers

DOI
10.1088/0143-0807/32/2/012;
PII
S0143-0807(11)76981-6;

Publishing Information

Journal Title
European Journal of Physics
Journal Volume
32
Journal Issue
2
Journal Page Range
p. 389-397
ISSN
0143-0807
CODEN
EJPHD4

INIS

Country of Publication
United Kingdom
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
43029474
Subject category
S71: CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS;
Descriptors DEI
ANGULAR MOMENTUM; EQUATIONS OF MOTION; ROLLING; ROTATION; TORQUE
Descriptors DEC
DIFFERENTIAL EQUATIONS; EQUATIONS; FABRICATION; MATERIALS WORKING; MOTION; PARTIAL DIFFERENTIAL EQUATIONS