I just saw an experiment where a heavy object (bowling ball) and a light object (feather) are dropped in a vacuum and they both fall at the same speed (almost like a slow motion video) and reach the bottom at the same time. But when the same two objects are dropped in a non vacuum environment, the ball hits the ground immediately while the feather has not even covered half the distance. I know this is somehow related to air resistance and terminal velocity and he air resistance reduces the acceleration of the ball to zero. but what I do not understand is that how come air resistance helps in increasing the speed of the ball ? Isn't it a kind of resistance ? Is it that in the vacuum experiment, the ball reaches the ground very quick and only the video is in slow motion ?
Thought of adding the video link as well:
https://www.youtube.com/watch?v=E43-CfukEgs
Best Answer
Well, the experiment was obviously filmed at a slower speed or shown at a slower speed. Both feather and ball should accelerate at around $9.8~\mathrm{m/s^2}$ and their velocities will be the same at all times. When there is air, the feather falls at much slower rate compared to the ball. Air resistance will decrease the acceleration of both but the effect of it will be much more on the feather.