So i know when an object is falling down to earth its 9.8m/s, well say a person is falling for 15 seconds and the person weighs 150 pounds would the person weight add to the speed that the person would achieve while falling to earth?
In: Physics
> So i know when an object is falling down to earth its 9.8m/s
That is incorrect. A falling object accelerates by 9.8m/s^2 if you ignore air resistance.
So after t seconde are t*9.8 so you get. The average speed is half the current speed so the distance you have fallen is d=t*t*9.8/2
* 1s* 9.8m/s^2 = 9.8m/s d=4.9m
* 2s* 9.8m/s^2= 19.6m/s d=19.6m
* 3s* 9.8m/s^2= 29.4m/s d=44.1m
* 4s* 9.8m/s^2= 39.2m/s d=78.4m
* 5s* 9.8m/s^2= 49m/s d=122.5m
* 6s* 9.8m/s^2= 58.8m/s d=176.4m
* …
* 15s* 9.8m/s^2= 147m/s d=1102.5m
In practice, air resistance is relevant and is proportional to the square of the speed. So a parachutist on the stomach with arms out only reaches 56m/s and head down with arms in you can reach 89m/s.
On the belly it it takes 12s to reach a terminal velocity of 56m/s and you have fallen around 450m
So a person falling for 15 s will be at or close to the terminal velocity and travel at less the 90m/s
The weight is irrelevant if you ignore air resistance so in a vacuum chamber a [feather and a bowling ball will reach the ground at the same time.](https://www.youtube.com/watch?v=E43-CfukEgs) But there is a clear difference in air.
For a human the body size scale with weight too so you have similar terminals velocity.
If you instead drop a bowling ball versus an inflated plastic ball with the same diameter the air resistance is identical but the wight differs a lot so the bowling ball have higher terminal velocity.
Latest Answers