(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

ABS plastic melts (and solidifies) at 105 °C. You want to inject it into a steel mold. When the part comes out at 20°C you want it to be 7.250cm long. Edit: If this isn't clear, it wants to know how big the steel mold should be.

α for ABS plastic α= 53.0x10^{6}/C°, for steel α= 11.0x10^{6}

2. Relevant equations

ΔL=αL_{0}ΔT

3. The attempt at a solution

Ok so I used the equation for linear expansion and I come out with an initial length of 7.282cm. The answer I'm given is 7.276cm. I'm think this has something to do with the steel but I have no idea what.

Edit: I tried a similar problem and got the right answer using the same method. I have no idea.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Thermal expansion: Plastic Molding

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**