If Kofi and Mei-Ling are in a room with a helium balloon on a string that Kofi is holding, and suddenly the gravity in the room is reversed, what will happen to the balloon? Provide a very brief response.
When gravity is reversed, the balloon will be pulled towards the new "down" direction, which is now the ceiling. Since the balloon is lighter than air, it usually floats upwards due to buoyancy when gravity acts normally, but if gravity reverses, the balloon, still being less dense than the air around it, will float towards the ceiling, which is now the direction of gravitational pull. The string will be taut and will point from Kofi's hand to the balloon on the ceiling. Kofi and Mei-Ling will also feel their own bodies being pulled towards the ceiling, assuming they are not anchored to the floor.