Calculating Change in Entropy: 1100 kg Cars Colliding at 75km/hr

[notsam]

Homework Statement

Two 1100 kg cars are traveling 75 km/hr in opposite directions when they collide and are brought to rest. Estimate the change in entropy of the universe as a result of this collision. Assume T= 15oC

Homework Equations

The Attempt at a Solution

PLEASE GET ME STARTED I am physics retarded an equation would be nice...

 

[pelmel92]

i imagine you're meant to use the relationship ∆S=k*log(w) where ∆s=entropy change, k is 1.380 6504(24)×10-23 J/K, and w is work...
work is kinetic energy, so...
got it?

 

[eliassiguenza]

Entropy can be calculated as:


S = k ln W ( w not as in work)

also you can use S = Q/T ---> Q being heat T ----> temperature,
I have learned that in thermo when they refer at universe is just whatever is outside your system. so define your boundary and i think it's pretty simple.

 

[eliassiguenza]

Also forgot to mention... you have an inelastic collision where two masses have momentum.! Remember that there is a release of energy in the form of heat because of the collision. I think that's the key for you to plug the formula as mentioned above.

However that guy who said w is work WRONG WRONG WRONG

W is the Wahrscheinlichkeit, the frequency of occurrence of a macrostate or, more precisely, the number of possible microstates corresponding to the macroscopic state of a system — number of (unobservable) "ways" in the (observable) thermodynamic state of a system can be realized by assigning different positions and momenta to the various molecules.

I know this because I just did a test on classical thermodynamics at uni ! =)
hope this helps you

 

[notsam]

Wait, how do I get Q (heat) from my mass and speed?