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Chapter 11 – Equilibrium and Elasticity - UCF Physics

Chapter 11 – Equilibrium and Elasticity - UCF Physics

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Proof:<br />

Each force F gi produces a torque τ i on the element<br />

of mass about the origin O, with moment arm x i .<br />

∑<br />

τ = r ⊥ F →τ<br />

i = xiFgi<br />

→τ<br />

net = τ i =<br />

i i<br />

∑<br />

x<br />

i<br />

F<br />

gi<br />

τ = x F = x ∑ F = τ<br />

cog<br />

g<br />

cog<br />

i<br />

gi<br />

net<br />

x<br />

cog<br />

→<br />

x<br />

∑<br />

i<br />

cog<br />

F<br />

gi<br />

=<br />

1<br />

=<br />

M<br />

∑<br />

i<br />

∑<br />

i<br />

x<br />

i<br />

F<br />

i<br />

gi<br />

x m<br />

i<br />

→x<br />

=<br />

x<br />

cog<br />

com<br />

∑<br />

i<br />

m g<br />

i<br />

i<br />

=<br />

∑<br />

i<br />

x m g<br />

i<br />

i<br />

i<br />

→<br />

x<br />

cog<br />

∑<br />

i<br />

m<br />

i<br />

=<br />

∑<br />

i<br />

x m<br />

i<br />

i

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