How Many Revolutions Before the Tube Breaks in Nonuniform Circular Motion?

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A 500 g ball attached to a 1.2 m tube experiences a perpendicular force of 4 N while rotating, with the tube's maximum tension at 50 N. The discussion revolves around calculating how many revolutions the ball can make before the tube breaks, starting from rest. Participants suggest finding the maximum velocity the tube can withstand and the time required to reach that velocity, emphasizing the relationship between the applied force and linear acceleration. Clarification is provided that the motion is nonuniform due to the changing linear velocity. The focus remains on deriving the necessary equations to solve the problem effectively.
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!Nonuniform Circular Motion

a 500 g ball rotates on a table while attached to a 1.2 m long tube. A force of 4 N is applied perpendicularly to the end of the tube. the max tension the tube can withstand is 50 N. if the ball starts from rest, how many revolutions does it make before breaking. friction is negligible.

m=500
r=1.2
F_perpendicular=4
F_radial_max=50
v_o=0

revolutions=?
 

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How would you begin to solve it? It is good to say what you've thought of, so you can receive help from that perspective.

As your formula indicates, the force applied on the tube depends on the velocity. So, how about finding the max velocity the tube can hold and then find the amount of time it takes to accelerate to it?
 
Those are some mighty fine equations you got there. Looks like all you need now is an expression for the linear velocity v. What do ya' think? Think it might have something to do with that perpendicular force causing a linear acceleration parallel to v?

And how is this not uniform circular motion...?

--J
 
Justin Lazear said:
Those are some mighty fine equations you got there. Looks like all you need now is an expression for the linear velocity v. What do ya' think? Think it might have something to do with that perpendicular force causing a linear acceleration parallel to v?

And how is this not uniform circular motion...?

--J

Nonuniform in the sense that linear velocity is not constant.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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