Hello there - this is my first time here, and I apologize for my lack of hard knowledge on physics. I'm a screenwriter working on a screenplay about Superman. I've always had a love of superheroes (especially Superman), but always wondered about some of the more physical aspects of it. Which brings me to the topic at hand: how hard can Superman punch? For the sake of argument, let's assume Superman has the same mass and proportions as a large human, so his fist would weigh about 2 kilos (I believe) and his body would weigh about 100 kilograms. Also, assume he's punching someone as durable as he is - say, General Zod, another resident of his home planet of Krypton who boasts the same powers on Earth as Superman. So proportionally to one another, it would be just like two humans duking it out. The final step, of course, comes down to the speed his fist can accelerate at. For let's argument's sake, let's do two separate calculations: First of all, let's say he can accelerate at one million times the speed of a human, to a million times the velocity. Basically, here his punch is a million times stronger than a human's (I believe) - but how powerful is that? And what is the acceleration and terminal velocity of his fist when it hits Zod? Secondly, let's take it to the limit. Say he can accelerate his fist to 99 percent of the speed of light when he throws a punch. How hard does that hit? I'm trying to look for bases of comparison for these, so if you could either provide them in Joules - or even better, simply give me analogous incidents of energy production. I'm trying to get a sense of the damage caused to the world around him when Superman gets into a fight. Are we talking 500 pound bomb blasts? Nuclear explosions? Earthquakes? Thank you very much - it really means a lot to me.