I think if Alom Shaha really wants to be a hit with younger people, 5 minute clips are too long. I reckon 2-3 minutes, the average Mtv length, is just about enough.
I dunno. I think it depends on which kids you're trying to reach & what you're trying to communicate, and I imagine this is a problem in general with conceiving science ed for kids. My 3-year-old is capable of sitting zombielike in front of a movie for 1.5 hours, and she'll follow argument & instruction through 45 minutes of educational kid video, if the narrator's friendly.
It's easy, too, to underestimate what the kids will pay attention to. Last summer I wrote a short piece on Shostakovich's 5th symphony for some remedial 9th-grade classes, for a unit questioning how important freedom of expression is to self-knowledge. I thought, well, this is culturally imperialist, and what do they care about a Russian guy with round glasses from a hundred years ago, but I don't care; I'll write about him & the music anyway because String Quartet No. 8 scares the hell out of me and I'm a Cold War antique. Which is not a great attitude businesswise, but as it turned out it was a hit; it seems the kids paid attention and got it.