The discussion centers on determining the speed at which an object falls from a known height, specifically addressing the influence of weight and the role of drag forces. Participants explore the physics behind free fall, including energy conservation principles and the effects of air resistance.
Participants express differing views on the role of weight in determining falling speed, with some agreeing on the independence of weight under certain conditions, while others emphasize the importance of considering drag forces, leading to an unresolved discussion regarding real-world applications.
The discussion includes assumptions about neglecting drag forces, which may not hold true in practical scenarios. The dependence of drag on geometry rather than mass is also noted, but not fully explored.
I know that you know this Fred, but for the benefit of the OP I will mention the caveat that an objects' instantaneous velocity is only independent of mass provided that the effects of drag are ignored.FredGarvin said:You do know that the speed an object falls is independent of its weight...right?
True. However it should be pointed out that drag is not proportional in any way to mass either. It is a function of geometry.Hootenanny said:I know that you know this Fred, but for the benefit of the OP I will mention the caveat that an objects' instantaneous velocity is only independent of mass provided that the effects of drag are ignored.
ATCLanser said:I am looking for a formula to determine what speed an object will fall with a known height and weight. For example a 220 pound man falls from 65 ft, what speed will he be going when he hits the ground?
aniketp said:There is a simple derivation for the formula below.
The kinetic energy at the moment the object hits the ground is 0.5mv^2 which is equal to its potential energy at given height "h"
Thus 0.5mv^2=mgh
And v=(2gh)^0.5 which is independent of the weight.