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Forces on hockey players : Vectors, work, energy and angular momentum

Nässén, Nina ; Nässén, Hans Ake ; Eriksson, Urban LU orcid and Pendrill, Ann Marie LU orcid (2019) In European Journal of Physics 40(6).
Abstract

Non-traditional examples can be very inspiring for students. This paper applies classical mechanics to different ways of skating in ice hockey. Skating blades glide easily along the ice in the direction of the blade. Horizontal forces on the skates are thus essentially perpendicular to the blade. Speed skaters glide long distances on each skate before pushing off for the next stride. A hockey player running for the puck may take a number quite short steps in a short explosive rush before shifting to longer strides, where the recurring need to change direction requires additional work by the skater. This paper investigates an alternative stride, with a longer gliding phase in a circular arc, where the centripetal force provided by the... (More)

Non-traditional examples can be very inspiring for students. This paper applies classical mechanics to different ways of skating in ice hockey. Skating blades glide easily along the ice in the direction of the blade. Horizontal forces on the skates are thus essentially perpendicular to the blade. Speed skaters glide long distances on each skate before pushing off for the next stride. A hockey player running for the puck may take a number quite short steps in a short explosive rush before shifting to longer strides, where the recurring need to change direction requires additional work by the skater. This paper investigates an alternative stride, with a longer gliding phase in a circular arc, where the centripetal force provided by the ice acting on the skates changes the direction of motion, without the need for additional energy. In addition, the conservation of angular momentum leads to increased speed as the centre of mass is shifted closer to the centre of the circular arc. Finally, we discuss an angular-momentum-based technique to reverse the direction of motion as fast as possible.

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Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
angular momentum, energy, hockey, mechanics, skating
in
European Journal of Physics
volume
40
issue
6
article number
065005
publisher
IOP Publishing
external identifiers
  • scopus:85076420280
ISSN
0143-0807
DOI
10.1088/1361-6404/ab3146
language
English
LU publication?
yes
id
f629327a-77bc-4b77-97cd-91794570095d
date added to LUP
2020-01-13 13:15:54
date last changed
2022-04-18 20:05:11
@article{f629327a-77bc-4b77-97cd-91794570095d,
  abstract     = {{<p>Non-traditional examples can be very inspiring for students. This paper applies classical mechanics to different ways of skating in ice hockey. Skating blades glide easily along the ice in the direction of the blade. Horizontal forces on the skates are thus essentially perpendicular to the blade. Speed skaters glide long distances on each skate before pushing off for the next stride. A hockey player running for the puck may take a number quite short steps in a short explosive rush before shifting to longer strides, where the recurring need to change direction requires additional work by the skater. This paper investigates an alternative stride, with a longer gliding phase in a circular arc, where the centripetal force provided by the ice acting on the skates changes the direction of motion, without the need for additional energy. In addition, the conservation of angular momentum leads to increased speed as the centre of mass is shifted closer to the centre of the circular arc. Finally, we discuss an angular-momentum-based technique to reverse the direction of motion as fast as possible.</p>}},
  author       = {{Nässén, Nina and Nässén, Hans Ake and Eriksson, Urban and Pendrill, Ann Marie}},
  issn         = {{0143-0807}},
  keywords     = {{angular momentum; energy; hockey; mechanics; skating}},
  language     = {{eng}},
  number       = {{6}},
  publisher    = {{IOP Publishing}},
  series       = {{European Journal of Physics}},
  title        = {{Forces on hockey players : Vectors, work, energy and angular momentum}},
  url          = {{http://dx.doi.org/10.1088/1361-6404/ab3146}},
  doi          = {{10.1088/1361-6404/ab3146}},
  volume       = {{40}},
  year         = {{2019}},
}