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Heat and Kinetic Energy Question

  • Thread starter a_narain
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Homework Statement


Two cars collide as both are traveling at 90km/hr. What is the increase in temperature of the wrecks, assuming that the cars have c = 447 joules/kelvin.


Homework Equations


Q= mc(change in T)


The Attempt at a Solution


I found the joules of kinetic energy equal to 625 joules * mass of car (25 m/s speed = 625/2 joules of KE per car X two cars).
I then divided that by 447 for the c value, to get 1.4 K. But the answer is not correct?
 

Answers and Replies

  • #2
LowlyPion
Homework Helper
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Homework Statement


Two cars collide as both are traveling at 90km/hr. What is the increase in temperature of the wrecks, assuming that the cars have c = 447 joules/kelvin.

Homework Equations


Q= mc(change in T)

The Attempt at a Solution


I found the joules of kinetic energy equal to 625 joules * mass of car (25 m/s speed = 625/2 joules of KE per car X two cars).
I then divided that by 447 for the c value, to get 1.4 K. But the answer is not correct?
Half of that would be correct though wouldn't it?

Don't you have to consider the total heat into the total mass?
 

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