(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A 45.0-cm diameter wheel, consisting of a rim and six spokes, is constructed from a thin rigid plastic material having a linear mass density of 25.0 g/cm. This wheel is released from rest at the top of a hill 52.0m high.

a.) How fast is it rolling when it reaches the bottom of the hill?

b.) How would your answer change if the linear mass density and the diameter of the wheel were each doubled?

2. Relevant equations

ME_{i}= ME_{f}

[itex]\omega[/itex] = V / R

3. The attempt at a solution

mgh_{i}= .5m*v^{2}+ .5I*(v^{2}/ R^{2})

v^{2}= (2*mgh_{i}) / (m + (I/R^{2}))

I = mR^2 + 6/3 *mR^2

= 3mR^2

v^2 = 2mgh / (m + (3mR^2 / R^2))

= .5 * gh_{i}

I get v = 15.96

but that is wrong?

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# Homework Help: Rotational kinematics using energy

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