• Support PF! Buy your school textbooks, materials and every day products Here!

Energy, Thermal Expansion

  • Thread starter ymehuuh
  • Start date
  • #1
19
0

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...
 

Answers and Replies

  • #2
LowlyPion
Homework Helper
3,090
4
Isn't 2.19*10-4m = .219 mm?
 
  • #3
19
0
Whoops...divided instead of multiplied. Thanks.
 

Related Threads for: Energy, Thermal Expansion

  • Last Post
Replies
2
Views
377
Replies
3
Views
962
  • Last Post
Replies
0
Views
1K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
2
Views
471
  • Last Post
Replies
0
Views
3K
  • Last Post
Replies
2
Views
1K
Top