How Do You Calculate the Probability Density Function in a Classical Ideal Gas?

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SUMMARY

The discussion focuses on calculating the probability density function for a classical ideal gas in three dimensions, specifically addressing the relationship between velocity and kinetic energy. The probability density function for the velocities is given by p(Vx,Vy,Vz) = C * exp(-(Vx^2 + Vy^2 + Vz^2)). The task involves deriving the overall probability P(E) that gas particles have kinetic energy less than E, and subsequently finding the probability density p(E) by relating it to the velocity components. Participants seek guidance on transforming the velocity-based expression into one that depends on energy.

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  • Understanding of classical mechanics, particularly kinetic energy concepts
  • Familiarity with probability density functions and statistical independence
  • Knowledge of multivariable calculus for integrating over velocity space
  • Basic grasp of exponential functions and their properties
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Homework Statement



Classical Ideal Gas in 3 Dimensions
In a classical ideal gas, we treat molecules as non-interacting point particles moving in the x,y, and z directions. These particles' velocities (in each respective direction) are statistically independent:

p(Vx,Vy,Vz)=C*exp-(Vx^2+Vy^2+Vz^2)

The energy is E=1/2*m*|v|^2

(a) Find P(E), the overall probability that these gas particles will have a KE \<E.
(b) By noting that dP=p(E)dE, derive the probability density p(E).

Homework Equations


No clue

The Attempt at a Solution


Don't even know how to start...any tips would be much appreciated
 
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Can you re-write the expression for p(Vx,Vy,Vz) so that the probability depends on E rather than Vx, Vy, and Vz?
 

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