- #1
GRB 080319B
- 108
- 0
Mass on a string undergoing uniform circular motion by hand:
I was taught that the centripetal force F = mV^2/R is a resultant force, and in this case was due to the tension force by the wire on the mass. I am trying to understand what is causing the tension and what causes the string to break at high speeds. Looking from above the plane of rotation, in order to keep the mass rotating, I appear to be moving my hand linearly back and forth to continue the circular motion of the mass. There has to be an applied torque to counteract the torque from friction (hand on string) trying to decrease the angular speed. I was wondering, is the torque that is causing the rotation a component of the normal force between the string and my hand? Is this normal force changing as my hand moves back and forth, or is it constant with respect to the center of mass of the system?
What force causes the string to break/ over comes the tension force? It can't be the centripetal force because the centripetal force is a resultant force. Does this have to do with the reactive centrifugal force, and what would the reactive centrifugal force be in this case (tension force by hand on wire)? Should I be thinking about this in terms of angular momentum and impulse?
Any help will be greatly appreciated
I was taught that the centripetal force F = mV^2/R is a resultant force, and in this case was due to the tension force by the wire on the mass. I am trying to understand what is causing the tension and what causes the string to break at high speeds. Looking from above the plane of rotation, in order to keep the mass rotating, I appear to be moving my hand linearly back and forth to continue the circular motion of the mass. There has to be an applied torque to counteract the torque from friction (hand on string) trying to decrease the angular speed. I was wondering, is the torque that is causing the rotation a component of the normal force between the string and my hand? Is this normal force changing as my hand moves back and forth, or is it constant with respect to the center of mass of the system?
What force causes the string to break/ over comes the tension force? It can't be the centripetal force because the centripetal force is a resultant force. Does this have to do with the reactive centrifugal force, and what would the reactive centrifugal force be in this case (tension force by hand on wire)? Should I be thinking about this in terms of angular momentum and impulse?
Any help will be greatly appreciated
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