Uniform Circular Motion and centripetal force

AI Thread Summary
The discussion focuses on uniform circular motion (UCM) and the role of centripetal force in an experiment involving a stopper and a weight. It highlights the contradiction in maintaining a horizontal circular path, as the vertical tension required to support the stopper's mass cannot be achieved. The participants agree that a horizontal circle is not physically feasible without vertical tension. The need for experimental precision is questioned, suggesting a deeper understanding of the forces at play is necessary. Overall, the conversation emphasizes the complexities of UCM and the conditions required for stability in circular motion.
BlueEight
Messages
18
Reaction score
0

Homework Statement


http://img.skitch.com/20091201-pxecs3d574itggpejybhdbp3qr.jpg

Essentially, as an experiment, our physics class whirled a stopper attached to a string that went through a tube that was finally attached to a weight on the bottom of the string.

The Attempt at a Solution


I'm not really sure, unless the centripetal force is somehow not adequate to hold the weight up, but it should be, as long as the stopper is swung around quickly enough.. This seems contradictory to everything that we've learned about UCM this semester.
 
Physics news on Phys.org
I think you need to show that a horizontal circle as show in the diagram is not physically possible?
 
Oh yeah! Because if it was horizontal, there would be no "vertical tension" holding up the mass of the stopper?
 
BlueEight said:
Oh yeah! Because if it was horizontal, there would be no "vertical tension" holding up the mass of the stopper?
yes

Tsinθ=mg, θ=0, the mass will not stay in a horizontal circle.
 
Ah, thanks. But why would it be "necessary for experimental precision?"
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Thread 'A cylinder connected to a hanged mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top