If the breaking force for a given wire is $F$, then the breaking force of two wires of the same material and same dimensions joined together in parallel will be

What is buckling? What should be the shape of a rod for preventing buckling?

For the tensile stress on the cross-section $PQRS$ to be maximum,$\theta =$ ......... $^o$

What are the factors on which the modulus of elasticity depends?

Two identical steel cubes (masses $50\,g$,side $1\,cm$) collide head-on face to face with a speed of $10\,cm/s$ each. Find the maximum compression of each. Young's modulus for steel $Y = 2 \times 10^{11}\,N/m^2$.

$A$ string $AB$ of unstretched length $L$ is stretched by applying a force $F$ at the mid-point $C$ such that the segments $AC$ and $BC$ make an angle $\theta$ with $AB$ as shown in the figure. The string may be considered as an elastic element with a force to elongation ratio $K$. The force $F$ is given by