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mihuhifitechno
mihuhifitechno
Student
High School - 10th Grade

By heating a metal ring, it's thickness has raised with f=0.40%. How many percent raised its inside diameter?

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Posted by mihuhifitechno on Monday June 22, 2009 at 9:37 AM and tagged with diameter, heat, metal, percent, science.

Answers:

  1. giorgiana1976
    giorgiana1976 Teacher
    Doctorate

    eNotes Editor

    By heating an isotropic body, all it's linear dimensions are raising in the same proportion:

    l1=l0(1+ alfa*t1)

    l2=l0(1+ alfa*t2)

    delta l= l2-l1=l0*alfa*(t2-t1)

    delta l= l0*alfa*delta t

    f=delta l/l0= l0*alfa*delta t/l0=alfa*delta t, fact which is obvious from the definition of the linear expansion coefficient: alfa=delta l/(l0*delta t).

    CONCLUSION: The inside diameter is increasing with f=0.40%, also!

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    Posted by giorgiana1976 on Monday June 22, 2009 at 9:56 AM

  2. neela
    neela Teacher
    Graduate School

    eNotes Editor

    The metal ring has not undergone any distorted  expansion,due to the heat.It has expanded according to the law in a related linear, surfacial and volume expansion-The ratio of rate of increases in linear , surface and volume expansion due to heat  is 1:2:3.

    Both thickness and diameter are a linear measure and so, the the diameter  increse is by the same % as the that of increse in thickness, i.e., 40%.

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    Posted by neela on Thursday June 25, 2009 at 9:35 PM