Heat and Kinetic Energy Question

AI Thread Summary
In a collision of two cars traveling at 90 km/hr, the kinetic energy calculated is 625 joules per car, resulting in a total of 1250 joules. The specific heat capacity is given as 447 joules/kelvin. The initial calculation of temperature increase was found to be 1.4 K, but this was deemed incorrect. The discussion highlights the need to consider the total heat and mass in the calculations for an accurate temperature change. Proper application of the heat equation is crucial for determining the correct increase in temperature of the wrecks.
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?
 
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a_narain said:

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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