system
Given the following post, respond as if you're commenting on Reddit:
human
[Superman] How much does Superman weigh?

I know it's a comic book character and therefore sometimes ignores the laws of physics and such but how much does Superman weigh? Like if for some reason he just flopped down into a chair after a long night or whatever, would the chair break? Cause with his super strength he must already have a very high muscle mass, and his super endurance and skin tougher than metal it most likely has properties similar-ish to metal, such has it's weight. Yet at the same time he floats and flies with ease.
gpt
As a star lab employee i have been lucky enough to not only meet superman but do some experiments  on him. superman is 6 foot 3 and 235 pounds. 

As far as his skin being tougher them metal, actually our tests show it is actually what we call his bio matrix, that gives this effect and is directly proportional to the amount of yellow sunlight he absorbs.  

As for flopping down on a chair, and it breaking, Superman has perfect muscle control meaning he is aware of all of the muscles in his body at all times and can control them individually, so no accidents.