I recently saw a trailer advertising the upcoming film "Passengers", starring Chris Pratt and Jennifer Lawrence. The movie is a science fiction thriller that takes place in outer space. The trailer can be seen here: https://www.youtube.com/watch?v=ATlwHzJKssQ . As shown in the trailer, a malfunction on the space shuttle causes the artificial gravity of the ship to be turned off while the character played by Jennifer Lawrence is taking a dip in the swimming pool. The result is that she is caught in a bubble that is rising upwards. I was curious about the physics behind this scene, and decided to think about it using some of the knowledge that we have learned in class this semester. Would it be possible to actually get stuck in that bubble? When the character is swimming she is able to float on the water. This is a result of both the force of gravity and the buoyancy force, we are assuming the volume of a human to be 0.069 cubic meters.
Fb= ρ fluidVfluid(g)= 1000 kg/m2*0.069m3*9.8m/s2= 1690N
As we can see, the buoyancy force is much greater than the force of gravity, so she is pushed upwards while in the water. However, when the gravity stops, the buoyancy force becomes 0, as there is no Fg. It is therefore actually considerable that she would no longer be able to float to the top of the bubble, as shown in the trailer.