Two structural steel support rods, P P\,P and QQQ, are made of the same steel alloy.
Rod P P\,P has an original length LLL, diameter ddd, and is subjected to a tensile force FFF. Under this force, rod P P\,P extends by a distance Δx\Delta xΔx.
Rod Q Q\,Q has an original length 3L, diameter 2d2d2d, and is subjected to a tensile force 6F6F6F.
Which statement is correct?
The strain in QQQ is 1.51.51.5 times the strain in PPP.
The stress in QQQ is 3.03.03.0 times the stress in PPP.
The extension of QQQ is 9.0Δx9.0 \Delta x9.0Δx.
The Young modulus of rod QQQ is 4.54.54.5 times that of rod PPP.
