$A$ horizontal steel railroad track has a length of $100 \, m$ when the temperature is $25^{\circ} C$. The track is constrained from expanding or bending. The stress on the track on a hot summer day,when the temperature is $40^{\circ} C$,is ............. $\times 10^7 \, Pa$. (Note: The linear coefficient of thermal expansion for steel is $1.1 \times 10^{-5} /^{\circ} C$ and the Young's modulus of steel is $2 \times 10^{11} \, Pa$.)

$A$ wire is suspended from a rigid support and a weight $W$ is attached to its free end,causing an extension of $1.0 \, mm$. If the same wire is passed over a pulley and a weight $W$ is attached to each of its two ends,what will be the extension in the wire in $mm$?

The adjacent graph shows the extension $(\Delta l)$ of a wire of length $1\, m$ suspended from the top of a roof at one end and with a load $W$ connected to the other end. If the cross-sectional area of the wire is $10^{-6}\, m^2$,calculate the Young's modulus of the material of the wire.

$A$ metallic bar of Young's modulus $0.5 \times 10^{11} \,N \,m^{-2}$, coefficient of linear thermal expansion $10^{-5} \,^{\circ}C^{-1}$, length $1 \,m$, and area of cross-section $10^{-3} \,m^2$ is heated from $0^{\circ}C$ to $100^{\circ}C$ without expansion or bending. The compressive force developed in it is:

The modulus of elasticity is dimensionally equivalent to

$A$ student performs an experiment to determine the Young's modulus of a wire, exactly $2 \,m$ long, by Searle's method. In a particular reading, the student measures the extension in the length of the wire to be $0.8 \,mm$ with an uncertainty of $\pm 0.05 \,mm$ at a load of exactly $1.0 \,kg$. The student also measures the diameter of the wire to be $0.4 \,mm$ with an uncertainty of $\pm 0.01 \,mm$. Take $g=9.8 \,m/s^2$ (exact). The Young's modulus obtained from the reading is