Two insulated metal bars are of rectangular cross$-$section with sides $1\mathrm{.}10$ cm and $3\mathrm{.}30$ cm and also have a length of $5\mathrm{.}80$ cm $.$ The bars are wedged between two walls, one held at $100\mathrm{.}30$ degrees Celsius and the other at $0$ degrees Celsius $($see figure$).$ Metal $1$ is lead and metal $2$ is silver. Find the temperature at the interface in degrees Celsius. degrees Celsius