1. The problem statement, all variables and given/known data hello there. i'm tried to design a fan which can overcome a force of 40N place on it. the project is actually somthng like future skateboard, where there are fans below the board. one more thing, i not too sure about the suitable power supply to use. any idea? 2. Relevant equations i just want to know what exactly need to be consider in order to build it. the RPM of the fan blade, the suitble size of the fan, the theory i need to know and any formula included in this project. 3. The attempt at a solution hopefully this project will work.