What is the derivation of the centripetal acceleration in terms of position?

AI Thread Summary
The discussion focuses on deriving centripetal acceleration in terms of position using the equation r(t) = Rcos(ωt) i + Rsin(ωt) j. The key equations include v = ωR and a = v²/R, leading to the conclusion that a(t) = -ω²r(t). Participants express concerns about the clarity of their derivations and the correctness of their answers, particularly in relation to a Mastering Engineering question. The final consensus confirms that expressing acceleration in vector form is accurate. The thread emphasizes the relationship between position, velocity, and acceleration in uniform circular motion.
unknown_2
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This problem has been discussed before, but one of the parts were not discussed.

Homework Statement


Your calculation is actually a derivation of the centripetal acceleration. To see this, express the acceleration of the particle in terms of its position r(t).

r(t) = Rcos(\omega t)\textbf{i} + Rsin(\omega t)\textbf{j}

Homework Equations



v = \omega R
a = \frac{v^2}{R}
a = \omega v

The Attempt at a Solution



v = \frac{d}{dt}r(t) \times \omega

btw, this is a Mastering engineering question, so i submitted and it says that:
The correct answer does not depend on the variables and functions: d, d, r.

is there another way to display this or am i missing something?

thx,
 
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Acceleration = V^2/R = w^2*R. In a uniform circular motion w and R are constant.
 
rl.bhat said:
Acceleration = V^2/R = w^2*R. In a uniform circular motion w and R are constant.

omg...too stressed out about finals...i think i got it =_=

please correct me if I'm wrong (again)...

a(t) = -\omega^{2}r(t)
 
unknown_2 said:
omg...too stressed out about finals...i think i got it =_=

please correct me if I'm wrong (again)...

a(t) = -<b>\omega^{2}r(t)</b>

If you express in the vector form, it is correct.
 
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