Calculate the tension in the rod

[Dr.Wasim]

Homework Statement

A steel rod 4.00 cm in diameter is heated so that its temperature increases by 70.0 C. it is then fastened between tow rigid supports. The rod is allowed to cool to its original temperature. Assuming that Young's modulus for the steel is 20.6 * 10^10 N/m^2
and that its avarege coefficient of linear expansion is 11 * 10^-6 1/C , Calculate the
tension in the rod.

Homework Equations

Delta L = L1 * alfa ( avarege coefficient of linear expansion ) * delta T

and

F / A = Y delta L / L

The Attempt at a Solution

I found delta L / L from first law above

then i found tension from second law

Is this true ?? please i need the answer today

Best wishes for you

 

[Dr.Wasim]

please help me

today the last time for answer

 

[Redbelly98]

Your method is correct.

 

[Dr.Wasim]

But i doubt in my method because the rod's length will decrease by cooling

and it will exert force on supporter

and my equation for solution contain avarege coefficient of linear expansion

not for compression ... understand me ?

 

[Redbelly98]

The coefficient of expansion applies equally to the case of cooling/contraction.