Find the diameter of a steel rod with a length of 1 m, if it is stretched by a force P = 65 kN, and its elongation \( \Delta l = 1.2 \ mm. E = 200 \cdot 10^9 Pa\)

Calculate the minimum diameter of the reinforcing steel rod with a design strength of R=205 MPa, subjected to a tensile force of N=10 kN.

At what value of compressive force P did the relative shortening \(\varepsilon=-0.0007\) of a steel rod with a cross-sectional area \(F=10\ cm^2\) occur? Data: \(E=200\ GPa\)

A steel rod with a diameter of d=32 mm and a length of l=35 cm was subjected to tensile stress with a force of P=135 kN. The strain measurements showed a decrease in diameter of \( \Delta d=0.0062\ mm\) and an elongation of \( \Delta l=0.04 mm \) over a measured section with a length of L=5 cm. Calculate the modulus of elasticity E and Poisson's ratio \( \nu \) for the material of the rod.

Calculate the stress in a flat bar 90×8 mm, weakened by holes for rivets with a diameter d=16 mm, subjected to a tensile force N=84 kN.