What is bending ? How bending problems prevents and what is buckling ?
A bridge has to be designed such that it can withstand the load of the flowing traffic, the force of winds and its own weight. Means it should not bend too much or break.
Similarly, in the design of building use of beams and column is very common.
In both the cases, the overcoming of the problem of bending of beam under a load is important.
Let us consider the case of a beam loaded at the centre and supported near its ends as shown in figure $(a)$.
A bar of length $l$, breadth $b$ and depth $d$ when loaded at the centre by a load $\mathrm{W}$ sags by an amount given by,
$\delta=\frac{\mathrm{W} l^{3}}{4 b d^{3} \mathrm{Y}}$
where $\mathrm{Y}=$ Young modulus
This equation shows that,
Bending $\delta \propto \frac{l^{3}}{b d^{3} \mathrm{Y}}$
Means for reduce the bending for the given load, the distance between two support must be small or one should use a material of beam with large Young's modulus.
When a weight of $10\, kg$ is suspended from a copper wire of length $3$ metres and diameter $0.4\, mm,$ its length increases by $2.4\, cm$. If the diameter of the wire is doubled, then the extension in its length will be ........ $cm$
If in case $A$, elongation in wire of length $L$ is $l$, then for same wire elongation in case $B$ will be ......
A uniform rod of length $L$ has a mass per unit length $\lambda$ and area of cross-section $A$. If the Young's modulus of the rod is $Y$. Then elongation in the rod due to its own weight is ...........
A steel rod of length $1\,m$ and area of cross section $1\,cm^2$ is heated from $0\,^oC$ to $200\,^oC$ without being allowed to extend or bend. Find the tension produced in the rod $(Y = 2.0 \times 10^{11}\,Nm^{-2}$, $\alpha = 10^{-5} C^{-1})$
A steel wire of diameter $2 \,mm$ has a breaking strength of $4 \times 10^5 \,N$.the breaking force ......... $\times 10^5 \,N$ of similar steel wire of diameter $1.5 \,mm$ ?