Angular Velocity of a turntable after weights are added

AI Thread Summary
The discussion revolves around calculating the angular velocity of a turntable after two weights are added. The turntable, initially rotating at 100 rpm, has a mass of 2.0 kg and a diameter of 20 cm. When two 500 g blocks fall onto it and stick, the conservation of angular momentum principle is applicable. Participants suggest using this principle to determine the new angular velocity post-event. The conversation emphasizes the importance of understanding angular momentum for solving the problem effectively.
doneganstm
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A 2.0 {\rm kg}, 20-cm-diameter turntable rotates at 100 {\rm rpm} on frictionless bearings. Two 500 {\rm g} blocks fall from above, hit the turntable simultaneously at opposite ends of a diagonal, and stick. What is the turntable's angular velocity, in rpm, just after this event?

I'm not quite sure on how to set this one up or what equation to use, can anyone give me a push in the right direction?
 
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Welcome to PF!

Hi doneganstm! Welcome to PF! :wink:

Hint: conservation of angular momentum. :smile:
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
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