A helium-filled balloon is being transported in a car. As the car accelerates away from a stop light, in which direction does the balloon move relative to the car?
The balloon will go forward as the car accelerates. This is because the "up" direction points more forward in an accelerating car. The reason the balloon knows the "up" direction points forward in an accelerating car is that the air ...
The solution uses theory of classical mechanics to describe the movement of a helium-filled balloon inside an accelerating car, relative to that car.