What is wrong with following physics equations? (velocity and acceleration)

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Discussion Overview

The discussion revolves around the correctness of various physics equations related to velocity and acceleration, particularly focusing on the relationships between average velocity, final velocity, and displacement. Participants explore the implications of different formulations and the conditions under which they hold true.

Discussion Character

  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant presents a series of equations relating average velocity, initial velocity, final velocity, and displacement, questioning the correctness of a commonly referenced formula.
  • Another participant challenges the equation Vf=at, suggesting it is not generally correct without additional context.
  • A later reply proposes that the correct formulation should include the initial velocity, leading to the equation Vf=Vi+at, indicating a misunderstanding in the application of the equations.
  • One participant raises a question about the fundamental units of acceleration, indicating a potential area of confusion or exploration.
  • Another participant reiterates the initial equations and points out that Vf=at assumes an initial velocity of zero, which contradicts the earlier equations where Vi is not zero.

Areas of Agreement / Disagreement

Participants express differing views on the correctness of the equations presented, with no consensus reached on the proper formulation or interpretation of the relationships between the variables.

Contextual Notes

There are unresolved assumptions regarding the initial conditions of the motion (e.g., whether initial velocity is zero) and the definitions of the variables used in the equations.

Selfphysicslearner
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vavg=(Vi+Vf)/2
vavg=h/t
then vavg*t=h
h=(Vi+Vf)/2 * t
Vf=at
(Vit+at2)*1/2=h
But formula on every resource I found says it should be;
(Vit+at2*1/2)=h
What mistake did I do ?
 

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Selfphysicslearner said:
Vf=at
Is it?
Are you missing anything here?
 
Last edited by a moderator:
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Selfphysicslearner said:
Vf=at
This is not generally correct.
 
cnh1995 said:
Is it?
Are you missing anything here?
I see it must be actually:Vf=Vi+at then there is 2 Vi in formula which eliminates 1/2 multiplied makes it
h=1/at^2 +2*1/2Vi
 
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What are the fundamental units of acceleration?
 
Selfphysicslearner said:
vavg=(Vi+Vf)/2
vavg=h/t
then vavg*t=h
h=(Vi+Vf)/2 * t
Vf=at
(Vit+at2)*1/2=h
But formula on every resource I found says it should be;
(Vit+at2*1/2)=h
What mistake did I do ?
Vf=at , this equation means final velocity = acceleration * time. This can happen only if initial velocity is 0, but in the equation Vi is the initial velocity and Vi is not 0 as per the equations wrriten.
 

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