$A$ brass disc fits snugly in a hole of a steel plate. To loosen the disc from the hole, the system should be:

Two large holes are cut in a metal sheet. If this sheet is heated,what happens to the distances $AB$ and $BC$ as shown in the figure?

$A$ thin copper wire of length $l$ meters is heated by $10^{\circ}C$,resulting in a $2\%$ increase in its length. If a square copper sheet of side $l$ meters is heated by the same $10^{\circ}C$,what is the percentage change in its area?

The temperature of a metallic sphere of radius $R$ is increased by a small amount $\Delta T$. If the linear coefficient of thermal expansion of the metal is $\alpha$, the approximate increase in the volume of the sphere is :

$A$ pendulum clock shows the correct time at $20^{\circ}C$. During summer days,when the temperature rises to $40^{\circ}C$,what will be the time change in the clock in one day (in $.64$)? (Given: $\alpha = 10^{-5} {^{\circ}C}^{-1}$)

Show that the coefficient of area expansion,$(\Delta A / A) / \Delta T,$ of a rectangular sheet of a solid is twice its linear expansivity,$\alpha_{l}$.