What is the change in length of an aluminum rod after adding 12500 J of energy?

AI Thread Summary
The discussion focuses on calculating the change in length of an aluminum rod after adding 12,500 J of energy. The initial parameters include a 23.0 cm rod at 20°C with a mass of 350 g. The relevant equations involve heat transfer and thermal expansion, with specific values for the coefficient of linear expansion and specific heat capacity. The user initially miscalculated the final temperature and the resulting change in length, confusing the conversion from meters to millimeters. Ultimately, the correct change in length is clarified as 0.219 mm after correcting the calculation error.
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Homework Statement


An aluminum rod is 23.0 cm long at 20°C and has a mass of 350 g. If 12500 J of energy is added to the rod by heat, what is the change in length of the rod?

Answer is in mm

Homework Equations


Q=m*c*delta T
deltaL=alpha*L0*deltaT
alpha=24x10^-6
c=900j/kg


The Attempt at a Solution


12500=.35kg*900(Tf-20C)
Tf=59.68

deltaL=24x10^-6*.23m*39.68
The answer I get is 2.19*10-4m which is wrong
That /1000 to get mm is 2.19*10-7 which is wrong

I don't understand what I did wrong...
 
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Isn't 2.19*10-4m = .219 mm?
 
Whoops...divided instead of multiplied. Thanks.
 

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