Dust-off is a difluoroethane based compressed air duster that we decided to use for our Floata-Buddy. Difluoroethane is about 2.97 kg per meter cubed. Based on the fact that water is 1000 kgs per meter cubed, we figured out that each meter cubed of Difluoroethane displaces 997 kgs of water. The average adult is about 0.08 cubic meters, displacing around 80 kgs of water, meaning that we only need to displace about 40 kgs of water to lift our goal of 250 pounds. Using calculations, we figured out that at 1 atm we only need 1.4 cubic feet of Difluoroethane. In a nutshell, here was our process:
- Figure out the densities of water and Difluoroethane
- Figure out how to use the ideal gas law
- Realise the ideal gas law has nothing to do with what we are doing
- Realize we made a mistake and use a different correct equation
- Find a correct number and at a pressure, we can use this much Difluoroethane(2 atm, 1.95 cubic feet)
- Realize we forgot the water displaced by the adult
- Include that in our equation and get a new number
