IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: pikutata on August 30, 2009, 05:02:58 am

Title: Physics Question.
Post by: pikutata on August 30, 2009, 05:02:58 am

hi,

the kinetic theory of gases leads to the equation

1/2m<c^2>=3/2kT.

mind explaining to me the significance of the quantity 1/2m<c^2>?

and using the equation to suggest what is meant by the absolute zero of temperature.

ps: this is past year questions for CIE PHYSICS A2 may/june 2002. paper 9704/4. question 3.

Title: Re: Physics Question.
Post by: abdullahnisar2005 on September 18, 2009, 09:47:03 am

see paper mark scheme

Title: Re: Physics Question.
Post by: astarmathsandphysics on September 18, 2009, 11:54:43 am

Quote from: pikutata on August 30, 2009, 05:02:58 am

hi,

the kinetic theory of gases leads to the equation

1/2m<c^2>=3/2kT.

mind explaining to me the significance of the quantity 1/2m<c^2>?

and using the equation to suggest what is meant by the absolute zero of temperature.

ps: this is past year questions for CIE PHYSICS A2 may/june 2002. paper 9704/4. question 3.

1/2m<c^2> is the average kinetic energy of the gas molecules
If this energy is zero then the left hand side is zero, so the right hand side must be zero, which can only happen if T=0, ie absolute zero since it is not possible for the left hand side to be less than zero.