- #1
Vitani11
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- 3
Homework Statement
A rod swings freely about a pivot. Is has mass M and length L. The average force and duration of hit are Fo and t respectively. A) What is the speed of the com of the rod just after It is hit? B) what is the horizontal component of the force exerted by the pivot on the rod? At what value of x is the center of percussion?
Homework Equations
V = (L^2) (omega) / (12x)
I of rod = (1/12)ML^2
X is distance down rod of applied force
The Attempt at a Solution
A has been found. I think C) is one third - and if it is that means I don't need help with b. To find B I just used the equation from A and multiplied it by mass and divided by time and reduced to m(L^2)*alpha/(12x). I set this equal to I*alpha for the pivot - the I of which I THINK is just mr^2. The moment of inertia of the pivot needs to be accounted for because it exerts a force on the rod in this case. This gave me 1/3 for part c. Is this correct? Because I used r for the pivot as L/2 (same L as rod) which can't possibly make sense...