what are some proxys that can get me on youtube at school?
A smoke detector doesn't know the difference between smoke from burning and vapor smoke or similar from a fog machine. If the particles in smoke or fog vapor interfere with the optics of the alarms, they will sound. Edit: The hookah doesn't make as much smoke or vapors as a fog machine. If your friend was directly under the smoke detector, it would go off. I've had a slightly burnt dinner or cook something too long in oil, and have the smoke set the alarm off. You couldn't see the smoke unless you lit it from behind. So it doesn't take much. It all depends on the location of said detector.
Congratulations! Your calculations are all dead on. If you're right about all of these things, then ask yourself, Self! Why is my answer is wrong? HINT: why didn't they tell tra7 There are some very nice trajectory calculators there. Don't use them unless absolutely necessary or you'll eat it on the test.