Can Physics Help Athletes Run Faster on a Curve Track

Sprinting on a curve is slower than sprinting on a straight lane. To explain this phenomenon, various models based on a combination of biological and physical assumptions have been developed. These models depend on detailed parameters that significantly differ for each individual athlete. Here, we propose a general model solely based on kinetic theory of physics that can be universally applied to all athletes. By solving the force and torque equations for the running speed of the athletes on a curved track, we analyzed sprinting speeds between the inner and outer curves. Applying the data from the classic works into our models, we find that our results and conclusions are mostly aligned with the previous works while our approach is built on the accurate physics principles and contains no uncontrollable parameters. Further we show how runners can alleviate the centrifugal effect of curved track by tilting their bodies and we quantitatively determine the optimal tilting angle for a given curvature.

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On the Planning and Construction of Railway Curved Track

International Journal of Vehicle Structures and Systems ◽

10.4273/ijvss.13.2.04 ◽

2021 ◽

Vol 13 (2) ◽

Author(s):

Sono Bhardawaj ◽

Rakesh Chandmal Sharma ◽

Sunil Kumar Sharma ◽

Neeraj Sharma

Keyword(s):

High Speed ◽

Time Derivative ◽

Railway Track ◽

Lateral Acceleration ◽

Transition Curve ◽

Railway Vehicle ◽

Geometric Conditions ◽

Curve Track ◽

Curved Track ◽

Transition Curves

Increasing demand for railway vehicle speed has pushed the railway track designers to develop high-quality track. An important measure of track quality is the character of the transition curve track connecting different intersecting straight tracks. A good transition curve track must be able to negotiate the intermittent stresses and dynamic effects caused by changes in lateral acceleration at high speed. This paper presents the constructional methods for planning transition curves considering the dynamics of movement. These methods consider the non-compensated lateral acceleration, deviation in lateral acceleration and its higher time derivatives. This paper discusses the laying methods of circular, vertical and transition curves. Key aspects in laying a curved track e.g. widening of gauge on curves are discussed in this paper. This paper also suggests a transition curve which is effective not only from a dynamic point of view considering lateral acceleration and its higher time derivative but also consider the geometric conditions along with the required deflection angle.

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A KINETIC DESCRIPTION OF PARTICLE FRAGMENTATION

Mathematical Models and Methods in Applied Sciences ◽

10.1142/s0218202506001406 ◽

2006 ◽

Vol 16 (06) ◽

pp. 933-948 ◽

Cited By ~ 5

Author(s):

PIERRE-EMMANUEL JABIN ◽

JUAN SOLER

Keyword(s):

Kinetic Theory ◽

Internal Energy ◽

General Model ◽

External Medium ◽

Mathematical Approach ◽

Kinetic Description ◽

Particle Fragmentation ◽

Proposed Model ◽

Internal Configuration ◽

Fragmentation Processes

This paper is concerned with the formulation and analysis of particle fragmentation by a mathematical approach of the kinetic theory. We consider a fairly general model which may require a description of the internal configuration of each particle, like internal energy. The fragmentation process is assumed to occur due to the configuration of the corresponding particle; an easy modification would allow one to consider the interaction with some external medium (typically a fluid) but we do not deal with fragmentation processes induced by particles collision here. The proposed model is therefore linear and may be analyzed with the use of correct entropies.

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Impacting Analysis on the Coupler and Buffer of a Subway Vehicle for the Shunting Operations

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.44-47.1687 ◽

2010 ◽

Vol 44-47 ◽

pp. 1687-1692

Author(s):

Suo Huai Zhang ◽

Ping Man Zhang ◽

Kun Jia

Keyword(s):

Kinetic Theory ◽

General Model ◽

Spline Function ◽

Theory Method ◽

Damping Force ◽

Moving Vehicles ◽

Non Linear ◽

Linear Damping ◽

The Relationship

After the general model of shunting operation was established, non-linear damping force was imported into ADAMS by means of spline function. Under the same coupling speed, the relationship between different shunting groups, the maximum impacting force and the buffer stroke was researched; the different impacting characteristics of the system were also analyzed under different shunting operations by means of the impulse transmission and kinetic theory method. In the condition of the same coupling speed and vehicles, the results are that the number difference of moving vehicles and static vehicles between the coupling interface was more, the maximum impacting force was smaller, and the buffer stroke was shorter.

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