(adsbygoogle = window.adsbygoogle || []).push({}); NOTE:In playing with the symbols it appears that I've made pi to be an exponent...um...so anytime you see that, please disregard it as pi is not meant to be an exponent anywhere here. Thanks!

1. The problem statement, all variables and given/known data

A gymnast is performing a floor routine. In a tumbling run she spins through the air, increasing her angular velocity from 2.60 to 5.40 rev/s while rotating through one half of a revolution. How much time does this maneuver take?

[tex]\omega[/tex]_{o}= 2.60 rev/s

[tex]\omega[/tex]_{f}= 5.40 rev/s

t = ?

[tex]\vartheta[/tex] = 2[tex]\pi[/tex] rev ---> But she only goes through 1/2 revolution. So this would be [tex]\vartheta[/tex] = 2[tex]\pi[/tex] rev / 2 . Or so I thought...

2. Relevant equations

I figured this equation would be appropriate since all variables, except t, are known.

[tex]\vartheta[/tex] = 1/2 ([tex]\omega[/tex]_{o}+ [tex]\omega[/tex]_{f}) t

3. The attempt at a solution

[tex]\vartheta[/tex] = 1/2 ([tex]\omega[/tex]_{o}+ [tex]\omega[/tex]_{f}) t

Solve for t

t = 2[tex]\vartheta[/tex] / ([tex]\omega[/tex]_{o}+ [tex]\omega[/tex]_{f}

t = 2 (2[tex]\pi[/tex] rev / 2) / (2.60 + 5.40)

t = 6.2831 [STRIKE]rev [/STRIKE]/ 8 [STRIKE]rev[/STRIKE]/s

t = 0.785s

Buuuut.....this is wrong. Any thoughts as I seem to be missing something?

Thanks!

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# Rotational Kinematics - A gymnast is performing a

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