Two cars collide, find temperature change

AI Thread Summary
Two cars collide head-on at 80 km/hr, converting their kinetic energy into thermal energy. The kinetic energy formula K = 0.5mv^2 is used to calculate the total energy, resulting in K = 492.8m after converting speed to meters per second. The heat transfer equation Q = cm(delta T) is applied, but the user mistakenly calculates a change in temperature rather than an absolute temperature. The discussion reveals confusion about unit conversion and the correct application of temperature change, with the user seeking clarification on their calculations. The final temperature increase remains unresolved, indicating further assistance is needed.
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Homework Statement



Two cars collide head on while each is traveling at 80 km/hr. Suppose all their kinetic energy is transformed into the thermal energy of the wrecks. What is the temperature increase of each car? (Assume each car's specific heat is that of iron)

Homework Equations



K = .5mv^2
Q = cm(delta T)
iron specific heat = .449 J/(g*K)

The Attempt at a Solution



K = 2(.5m(22.2)^2) = 492.8m

(converted 80 km/hr to m/s)

Q = 492.8m = (.449)(2m)T
T = 548.8 K
= 275.6 C

Which is the wrong answer. I don't know what i am doing wrong. Can someone please help me. Thanks
 
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Well, for one, there is no reason to convert your units. You calculated a \Delta T, not a temperature, and \Delta °C = \Delta K. Is the correct answer 549.9 K?
 
Oh yeah, I see what your saying. However 549 is still the wrong answer, so i must be doing something else wrong too.
 
Can anyone help me? I am really stuck...
 

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