Question: How are jetpacks able to lift up your whole body?

Ciarán O'Brien answered on 17 Nov 2014:

It’s because of something a smart chap called Isaac Newton figured out. If a force acts on an object, then that object exerts and equal force in the opposite direction.

Jetpacks shoot out gas. they shoot it downwards at great force. This creates and equal force on the jetpack in the opposite direction, so it will move upwards to balance out. If you happen to be wearing the jetpack, you’ll move with it! Jetpacks shoot out the gas hard enough that the force is enough to lift a person.

It’s hard to store that much gas in a jetpack though, so they don’t let you fly for very long 🙁