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vicTURBO
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Homework Statement
Hey everyone I'm new here and I'm completely stuck on the logic behind this question.
A 230 kg beam 2.7m in length slides broadside down the ice with a speed of 18 m/s. A 65 kg man at rest grabs one end as it goes past and hangs on as both he and the beam go spinning down the ice. Assume friction less motion. With what angular velocity does the system rotate about its Center of Mass?
Homework Equations
L= Iw
L_initial = L_final
(I_rod + I_man )w = mvr
The Attempt at a Solution
So first I found the new center of mass when the man grabs the beam.
New CM = [m_beam(0) + m_man(2.7/2)]/(m_beam + m_man)
L_initial = L_final
The answer key uses this as their primary equation, with r_beam = the new center of mass of the man with the beam
(m_beam)(v_initial)(r_beam) = (I_rod + I_man) w
My question is why does the initial angular momentum include the new center of mass (with the man and the beam)? Shouldn't it only include variables of only the beam since the beam is moving by itself initially?
Thanks for your help