Gohan VS Superman
Can Superman survive a full power Kamehameha from Ultimate Gohan?
The propulsive power of one of SSJ2 Gohan's Kamehamehas can drive objects into the sun in seconds, it can destroy the mass of a solar system, and that was when he was 11 years old.
Ultimate Gohan was Gohan at his maximum potential, at the point where he couldn't get any stronger, he was infinitely more powerful than Gohan SSJ2.
So Gohan SSJ2's Kamehameha should be able to destroy thousand upon thousands of Solar Masses, thats a fraction of the entire galaxy, but thats just the explosion, the actually Kamehameha's push usually annihilates the cell's of beings that are durable enough to survive nukes without a scratch (Like Cell) Because in Manga Vo 19 Gohan SSJ2's Kamehameha beam alone annihilates Super Perfect Cell down to his cells, and blew him into the sun.