How Fast Can a Ring with Uneven Mass Distribution Roll Without Hopping?

AI Thread Summary
The discussion focuses on determining the maximum velocity at which a ring with uneven mass distribution can roll without hopping. It involves a ring of mass m and radius r, with three attached masses (O, P, and Q) affecting its dynamics. Key equations include the moment of inertia of the ring and torque related to angular acceleration. Participants emphasize the importance of understanding the forces at play, particularly the upward force and normal reaction, to prevent the ring from losing contact with the ground. The conversation highlights the need for clarity on the conditions that lead to hopping during motion.
C-137
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Homework Statement
Let there be a ring of mass m and radius r. Let 3 masses be attached to the ring and named as O,P and Q. Mass of O and Q is 2m and mass of p is M. The angle between 2 masses is 15 degrees as shown in the figure.
Find the maximum velocity the ring must roll so that it doesn't hop while rolling i.e. to roll normally (without slipping), not bouncing.
Relevant Equations
Moment of inertia of a ring= mr^2
torque= I*(alpha)
Problem Statement: Let there be a ring of mass m and radius r. Let 3 masses be attached to the ring and named as O,P and Q. Mass of O and Q is 2m and mass of p is M. The angle between 2 masses is 15 degrees as shown in the figure.
Find the maximum velocity the ring must roll so that it doesn't hop while rolling i.e. to roll normally (without slipping), not bouncing.
Relevant Equations: Moment of inertia of a ring= mr^2
torque= I*(alpha)

Tried hard.
 

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Hello Cs, :welcome:
C-137 said:
Tried hard.
That's always good. But not good enough at PF. So post your trials to allow us to assist! What's the criterion for hopping off the ground ? At what point in the rotation would that happen ?
 
I guess when
total upward force + normal reaction >= mg
 
What upward force is there except for normal reaction force ?

And what expressions do you have for these ?
 
C-137 said:
I guess when
total upward force + normal reaction >= mg
You are assuming that leaving the ground means the mass centre of the system is accelerating upwards. If I trip while running, I am likely airborne while accelerating downwards,
 
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