Answer
(a) $8.45\times 10^2m/s$
(b) less than
Work Step by Step
(a) We can find the initial required speed as
$v_{\circ}=\sqrt{2g^{\circ}h}$
We plug in the known values to obtain:
$v_{\circ}=\sqrt{2(1.8m/s^2)(2\times 10^5m)}$
$v_{\circ}=8.45\times 10^2m/s$
(b) We know that $h\propto \frac{1}{g}$ and the gravitational acceleration on Earth is greater than that on Io. Therefore, the maximum height of the ejected lava on Earth would be less than that on Io.
