Terminal Velocity: What is it?

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Discussion Overview

The discussion centers on the concept of terminal velocity, exploring the conditions under which an object reaches a constant velocity during free fall. Participants examine the roles of gravitational force and air resistance, and how these forces interact to produce terminal velocity. The conversation includes theoretical considerations and examples related to the physics of falling objects.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant suggests that terminal velocity occurs when air resistance equals gravitational force (mg), leading to a constant downward velocity.
  • Another participant argues that during terminal velocity, there is no acceleration, and thus the velocity does not continue to increase as it would in a vacuum.
  • A participant expresses confusion regarding the implications of initial velocity in the context of terminal velocity.
  • Some participants clarify that terminal velocity is often treated as a fixed value, although they note that actual velocity may vary slightly due to changing air resistance with altitude.
  • There is a discussion about the analogy of a car maintaining a constant speed, which parallels the concept of terminal velocity where forces are balanced.

Areas of Agreement / Disagreement

Participants generally agree on the basic principle that terminal velocity is reached when air resistance equals gravitational force, but there is some disagreement regarding the implications of initial velocity and the nature of acceleration at terminal velocity. The discussion remains unresolved on certain technical aspects.

Contextual Notes

There are limitations in the discussion regarding the assumptions made about initial conditions and the effects of changing air resistance with altitude. Some mathematical steps and definitions are not fully explored, leaving room for further clarification.

Who May Find This Useful

This discussion may be useful for individuals interested in physics concepts related to motion, forces, and the dynamics of falling objects, particularly in understanding the nuances of terminal velocity.

Hardik Batra
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I want to know about terminal velocity.

As my point of view, when air resistance and force(=mg) become same then the object

moving downward has constant velocity.

This is right?

If right then v = (initial velocity)v + g*t; becomes v = g*t;

then velocity increases by time !
 
Last edited:
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Velocity increases in time when you have an acceleration. Your equation has a "g" in there as though its accelerating in a vacuum. If you want to consider terminal velocity then you have air resistance providing an opposite force to gravity (not the same). When this happens you don't have accereleration at "g", you have 0 acceleration. This would make your equation v = (initial velocity)v + 0*t; becomes v = (initial velocity)v.
 
I am not understanding what you are saying?

Example : If you are drop down a ball from 1000 m height of a building, Now As you are saying

that v = initial velocity(v)?
 
when air resistance and force(=mg) become same then the object

moving downward has constant velocity.

This is right?

yes. When the drag [or force] of air resistance equals the force of gravity, mg, the object
falls at some terminal velocity...often taken to be some fixed velocity.

Of course as air resistance increases as altitude decreases the ACTUAL velocity of a falling object might increase slightly, but this is often ignored.
 
Naty1 said:
yes. When the drag [or force] of air resistance equals the force of gravity, mg, the object
falls at some terminal velocity...often taken to be some fixed velocity.

Of course as air resistance increases as altitude decreases the ACTUAL velocity of a falling object might increase slightly, but this is often ignored.

I want to know how terminal velocity is being constant?
 
I want to know how terminal velocity is being constant?

Are you asking WHY it is constant?? because when air drag equals mg, there is no net force to accelerate an object.

so no acceleration...

Just like a car cruising down the highway at say, a steady 60 mph,...rolling friction and air drag and mechanical losses equals the force provided by the engine...
 

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