Answer
$\int~E\cdot ds = 1.07\times 10^{-3}~V$
Work Step by Step
$\int~E\cdot ds = -\frac{d\Phi}{dt}$
$\int~E\cdot ds = -A~\frac{dB}{dt}$
$\int~E\cdot ds = -(\pi~r_1^2)~\frac{dB}{dt}$
$\int~E\cdot ds = -(\pi)~(0.20~m)^2~(-8.50~mT/s)$
$\int~E\cdot ds = 1.07\times 10^{-3}~V$
