Deriving Big 5 Motion Laws Non-Calculus and Calculus

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The discussion focuses on deriving the five fundamental motion laws using both calculus and non-calculus methods. Key derivations include the equations for velocity (v = at + v0) and displacement (x = v0t + 1/2 at^2) through integration and basic definitions of acceleration. The user seeks clarification on the average velocity formula (vavg = (v0 + v)/2) and the derivation of the equation (Δv^2 = 2ax) using both methods. The conversation highlights the importance of understanding these principles in physics.

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  • Understanding of basic kinematics concepts
  • Familiarity with calculus, specifically integration
  • Knowledge of the definitions of velocity and acceleration
  • Ability to manipulate algebraic equations
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  • Study the derivation of the average velocity formula using calculus techniques
  • Explore non-calculus methods for deriving Δv^2 = 2ax
  • Learn about the implications of constant acceleration in motion equations
  • Investigate graphical representations of motion to reinforce understanding of kinematic equations
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Students of physics, educators teaching kinematics, and anyone interested in understanding motion laws through both calculus and non-calculus approaches.

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"Simple" derivations

I set out trying to derive the big 5 motion laws not only regularly, but calculus-style:

dv=adt
Integration yields v=at + C, and thus we get v=at+v0.
Non-calculus method is just using the definition of a=deltav/deltat and is trivial.

dx=vdt
x=(v0+at)dt
x=v0t + 1/2at^2 + C, and thus x=v0t + 1/2 at^2 + x0.

dx=v0dt
x=(v-at)dt
x=vt-1/2at^2+C, and thus x=vt-1/2at^2 + x0.

vavg=xt, and vavg=(v0+v)/2...i get that because of simple math and graphing with constant acceleration, but is there a calculus way to prove this?

What are the non-calculus derivations for the two i just mentione above.
Also, the last one has completely stumped me...(deltav^2=2ax), both non-calculus and calculus methods. If you have any hints/derivations with which to enlighten me, that would be much appreciated. Thanks.
 
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quincyboy7 said:
I set out trying to derive the big 5 motion laws not only regularly, but calculus-style:

dv=adt
Integration yields v=at + C, and thus we get v=at+v0.
Non-calculus method is just using the definition of a=deltav/deltat and is trivial.

dx=vdt
x=(v0+at)dt
x=v0t + 1/2at^2 + C, and thus x=v0t + 1/2 at^2 + x0.

dx=v0dt
x=(v-at)dt
x=vt-1/2at^2+C, and thus x=vt-1/2at^2 + x0.

vavg=xt, and vavg=(v0+v)/2...i get that because of simple math and graphing with constant acceleration, but is there a calculus way to prove this?

What are the non-calculus derivations for the two i just mentioned above.
Also, the last one has completely stumped me...(deltav^2=2ax), both non-calculus and calculus methods. If you have any hints/derivations with which to enlighten me, that would be much appreciated. Thanks.

Somewhat solved. a=dv/dt=(dv/dx)(dx/dt)=vdv/dx. Then adx=vdv and ax=v^2/2 + C and so the show goes on. Wicked relieved, but still would appreciate any calculus answers to why vavg=1/2 (v0+v) and a non-calculus answer to the last rule still.
 

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