- #1
yandao87
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Homework Statement
A 16.00 lead sphere is hanging from a hook by a thin wire 3.20 long, and is free to swing in a complete circle. Suddenly it is struck horizontally by a 5.50 steel dart that embeds itself in the lead sphere.
What must be the minimum initial speed of the dart so that the combination makes a complete circular loop after the collision?
Homework Equations
The Attempt at a Solution
1) I've try equating T = mv^2 / r = mg when the sphere reaches the top of the swing.
v=5.6 as r = 3.2 and m cancels out.
2) then initial p = final p
5.5 v = (16+5.5) (5.6)
i'll get initial v of 21.9m/s for the dart but its wrong.
can anyone tell me what's wrong? or should i just the mgh PE at the top approach?