1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Wires in an circuit, different materials, heat

Tags:
  1. Jan 2, 2018 #1
    1. The problem statement, all variables and given/known data
    In an electric circuit, consisting of copper wires with cross section area of Sc=5mm2 and a temperature of t=25C, a lead fuse is added melting when the copper wire temperature increases by Δt=25C. Find the cross section area of the lead fuse wire Sl=x.
    specific heat: cc=400J/kg*C cl=140J/kg*C.
    Lead melting point tl=327C, latent heat λ=25000J/kg.
    Specific electrical resistances of the materials: ρc=0,017*10-6Ωm, ρl=0,21*10-6Ωm.
    material density: ρc1=8,9*103kg/m3, ρl1=11,34*103kg/m3.

    2. Relevant equations
    Q=cmΔt
    Q=λm
    R=lρ/S

    Thank you for any ideas on how to solve this, if there is something confusing please ask, this equation is translated from a different language so there may be inaccuracies and such.
     
  2. jcsd
  3. Jan 2, 2018 #2

    BvU

    User Avatar
    Science Advisor
    Homework Helper
    2017 Award

    Don't erase the part 3. Attempt at solution. We can't help if you don't post that...
     
  4. Jan 2, 2018 #3
    I was asking for ideas, directions to try going towards, I'm not asking people to solve it. Anyway, I was thinking about Q1=Q2 Q1=ccm1Δt Q2=cl(tl-t). But I don't know the masses nor anything derivative from it since I need to find the cross section area.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted