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This programme is a general introduction to the kinetic theory of gases, making extensive use of large-scale models of molecules. John Walters introduces the programme with a look at the gas equat...ion PV = nrtT and the assumptions of kinetic theory. Keith Hodgkinson then shews us a mechanical analogue: elastically colliding pucks on an air table. He uses a "piston" to give us a fixed "volume" and shows that an increase in "T" leads to an increase in "V". He then shows us (electronically) the "random walk" of a single puck. John then uses a few frames of the pucks to build up the Maxwell-Boltzman distribution of velocities, shows us random motion of smoke particles viewed through a microscope, and describes Zartman's experiment to measure the distribution of speeds. Keith considers whether kinetic theory might be extended to liquids, and models evaporation as if it were a kinetic phenomenon. With the help of a model, John discusses evaporation in more detail, and then goes on to the importance of root mean square velocity, its molecular mass dependence, and diffusion. Keith shows us diffusion through a porous barrier, and John describes its application in purifying uranium.
Metadata describing this Open University video programme
Module code and title: S271, Discovering physics
Item code: S271; 13
First transmission date: 21-07-1982
Published: 1982
Rights Statement:
Restrictions on use:
Duration: 00:23:00
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Producer: Nick Brenton
Contributors: Keith Hodgkinson; John Walters
Publisher: BBC Open University
Keyword(s): Brownian motion; Kinetic theory of gases; Maxwell-Boltzmann distribution of velocities; Models of molecules; Uranium purification; Zartman's experiment
Master spool number: HOU3847
Production number: FOUS236R
Videofinder number: 1792
Available to public: no