Jupiter's moon Io has active volcanoes (in fact, it is the most volcanically active body in the solar system) that eject material as high as 500km (or even higher) above the surface. Io has a mass of 8.94×10^22 [kg] and a radius of 1815km . Ignore any variation in gravity over the 500km range of the debris. How high (in km) would this material go on earth if it were ejected with the same speed as on Io? I've calculated g from g = GM/R^2. What equation would I use to calculate the launch speed, v_0, for y= 500,000 m?