This description, up to changes in the numbers involved, seems to be a common exercise set to physics students. I've found people asking for help with this problem or trivial variants at Yahoo Answers, Chegg, Physics Forums, PTC, Express Helpline, as well as actual answer sheets from a college physics course ... and all of these links were just on the first page of Google results for
superman hurls asteroid.
Having studied maths and physics, I can tell you two things from experience.
- Firstly, there are many specific exercises which 'do the rounds' and somehow crop up in dozens of textbooks and courses on a given topic from all over the place. Sometimes there's a seminal textbook in the field which has influenced all the others; sometimes the 'original source' (if there is one) is more or less impossible to track down and teachers have just been copying the exercise from each other since time immemorial. So, don't expect to always be able to find an original source for much-reused problems.
- Secondly, it's common practice to make these kinds of exercise more 'fun' by involving some fictional characters. If you're going to set your class a problem about an object moving through space, why not make it Davros or the USS Enterprise? If you're going to set them a problem about an object interacting with a much larger one, why not make it Superman doing something heroic? But few teachers have the dedication to design an exercise around a real sci-fi story, instead picking facts and variables to make the story fit the exercise. So, don't expect there to be a real story behind a physics problem in a sci-fi context.
However, all that being said ... I did find a potential real source for the Superman asteroid problem!
Thanks to the book The Ages of Superman: Essays on the Man of Steel in Changing Times, edited by JJ Darowski, I discovered the comic issue World's Finest Comics #68 (1954), in which:
"The Menace from the Stars!" (Superman) written by Unknown, penciled by Wayne Boring and inked by Stan Kaye. Superman stops an asteroid on a collision course with Earth - but Kryptonite in the asteroid's make-up leave him with amnesia, and the effects of the asteroid are far from over on Earth too!
This story seems to have been based on an episode of the TV series Adventures of Superman, which seems to be better known than the comic, namely "Panic in the Sky" (1953), in which:
Superman rams a giant asteroid on a collision course with Earth. The impact causes the asteroid to now orbit the planet. However, Superman is staggered as he returns to Earth. He manages to change back to Clark Kent (apparently a reflex action) but doesn't remember who he is. Meanwhile, the orbiting asteroid still presents hazards for Earth. Only Superman can place an explosive device that will demolish the asteroid -- and no one, including Clark, knows where Superman is.
Both of these stories feature Superman dealing with an asteroid, and the TV episode for sure (probably the comic too) specifically features him colliding with it in space, as in the physics problem you cite. So these stories, if anything, were probably the inspiration for your exercise.