What must be the lengths of steel and copper rods at $0^o C$ for the difference in their lengths to be $10\,cm$ at any common temperature? $(\alpha_{steel}=1.2 \times {10^{-5}} \;^o C^{-1})$ and $(\alpha_{copper} = 1.8 \times 10^{-5} \;^o C^{-1})$
$30\, cm$ for steel and $20\,cm$ for copper
$20\,cm$ for steel and $30\,cm$ for copper
$40\,cm$ for steel and $30\,cm$ for copper
$30\,cm$ for steel and $40\,cm$ for copper
A structural steel rod has a radius of $10\,mm$ and length of $1.0\,m.$ A $100\,kN$ force stretches it along its length . Young's modulus of structural steel is $2 \times 10^{11}\,Nm^{-2}.$ The percentage strain is about ....... $\%$
A rigid bar of mass $15\; kg$ is supported symmetrically by three wires each $2.0\; m$ long. Those at each end are of copper and the middle one is of iron. Determine the ratios of their diameters if each is to have the same tension.
The following four wires are made of the same material. Which of these will have the largest extension when the same tension is applied ?
Figure shows the strain-stress curve for a given material. What are $(a)$ Young’s modulus and $(b)$ approximate yield strength for this material?
A stone is tied to an elastic string of negligible mass and spring constant $k$. The unstretched length of the string is $L$ and has negligible mass. The other end of the string is fixed to a nail at a point $P$. Initially the stone is at the same level as the point $P$. The stone is dropped vertically from point $P$.
$(a)$ Find the distance $'y'$ from the top when the mass comes to rest for an instant, for the first time.
$(b)$ What is the maximum velocity attained by the stone in this drop ?
$(c)$ What shall be the nature of the motion after the stone has reached its lowest point ?