Physics - Elasticity Question with Solution | TestHub

A bottle has an opening of radius$\mathrm{a}$and length$\mathrm{b}$. A cork of length$\mathrm{b}$and radius$\left(\mathrm{a}+∆\mathrm{a}\right)$where$\left(∆\mathrm{a}\ll \mathrm{a}\right)$, is compressed to fit into the opening completely (see figure). If the bulk modulus of cork is$\mathrm{B}$and the coefficient of friction between the bottle and cork is$\mathrm{\mu }$, then the force needed to push the cork into the bottle is