A flexible loop of conducting wire has a radius of $0.12 \mathrm{m}$ and is perpendicular to a uniform magnetic field with a strength of $0.15 \mathrm{T}$, as in figure (a) below. The loop is grasped at opposite ends and stretched until it closes to an area of $3 \times 10^{-3} \mathrm{m}^{2},$ as in figure (b) below. If it takes $0.20 \mathrm{s}$ to close the loop, find the magnitude of the average emf induced in the loop during this time. (FIGURE CAN'T COPY)