Answer:
91.5 km
Explanation:
Hi!
If we are to ignore the variation in gravity we can use the formula for teh potential energy near the surface of a planet:
mgh
If the energy of the material ejected from the volcano on Io's surface is the same on earth's surface we have:

where subindexes Io and e means Jupiter's moon Io, and Earth, respectively
solving for h_e

The acceleration due to the gravity of a planet can be calculated as:

Where R and m are the radius and mass of the planet
Therefore:

m_e = 5,972 × 10^24 kg
R_e = 6 371 km
Replacing all given values:
h_e = 500 km *(0.183) = 91.515 990 km