The energy required to completely vaporise something as Roshi did (as suggested by its complete destruction and smoke/steam coming from the explosion), and the energy required for this feat would be at least Small City level going by most calcs: https://www.narutoforums.org/xfa-blog-entry/size-of-mount-fry-pan-revised.14344/
https://vsbattles.fandom.com/wiki/User_blog:FanofRPGs/Master_Roshi_destroys_Mount_Frypan
Goku kicked the missile before it detonated and was in complete awe at the power of the explosion, so him kicking it away means little. Someone capable of being fatally wounded by a grenade like Tao Pai Pai was capable of still damaging Goku, yet Goku could kick the grenade away before it explosion.