Proving the equations of motion

AI Thread Summary
The discussion revolves around the integration of the equation of motion, v = u + at, leading to the position equation s = ut + (1/2)at^2 + C. The integration constant C represents the initial position of the particle at time t = 0. It can be set to zero by choosing the origin of the coordinate system at that point. Participants clarify that the constant is not something to be dismissed but is essential for accurately describing motion. The conversation concludes with an acknowledgment of the clarity provided regarding the integration constant.
misogynisticfeminist
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If I got v=u+at

i get, \int v = \int (u+at) dt

which is s=ut+\frac {1}{2} at^2 + C

how do i explain away the integration constant in this derivation?
 
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You can't.It's x(0),the initial position.You can set it to zero,if u want by chosing the origin of the coordinate system in that very point.

Daniel.
 
misogynisticfeminist said:
If I got v=u+at

i get, \int v = \int (u+at) dt

which is s=ut+\frac {1}{2} at^2 + C

how do i explain away the integration constant in this derivation?

Why do you need to `explain away' the constant of integration. The constant C corresponds to the position of the particle when t = 0. Thus you have
<br /> \begin{align*}<br /> x &amp; = \frac{1}{2} a_xt^2 + u_xt + x_0 \\<br /> x - x_0 &amp; = \frac{1}{2} a_xt^2 + u_xt \\<br /> s_x &amp; = \frac{1}{2} a_x t^2 + u_xt.<br /> \end{align*}<br />
 
jdstokes said:
Why do you need to `explain away' the constant of integration. The constant C corresponds to the position of the particle when t = 0.

that's the explanation i needed lol, thanks alot...it didn't occur to me then.
 
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