Understanding the Motion of a Falling Rod on a Frictionless Surface

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SUMMARY

The discussion centers on the motion of a falling rod on a frictionless surface when given a slight push. It is established that the rod experiences both translational motion and rotational motion about its center of mass (CM). As the lower end of the rod slips on the surface, the CM moves vertically downward while the rod rotates. The combination of these motions is crucial for understanding the dynamics of the system.

PREREQUISITES
  • Understanding of rotational dynamics and center of mass (CM)
  • Familiarity with Newton's laws of motion
  • Knowledge of frictionless surfaces in physics
  • Basic concepts of kinematics and motion analysis
NEXT STEPS
  • Study the principles of rotational motion and angular momentum
  • Explore the concept of center of mass in rigid body dynamics
  • Learn about the effects of friction on motion and how it alters dynamics
  • Investigate the mathematical modeling of motion on frictionless surfaces
USEFUL FOR

Physics students, educators, and anyone interested in understanding the dynamics of rigid bodies in motion, particularly in scenarios involving frictionless surfaces and rotational dynamics.

nil1996
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A rod initially held vertically is falling on a frictionless surface when given a slight push.I just want to how the rod would move.I am thinking that the rod as a whole will move forward and also rotate about the point on the ground.

Why the rod is moving forward?(if you ask me)
I think that the CM is going in circular motion and thus will experience an outward pull. This force will take the rod forward.

But i have heard that the rod purely rotates and does not move forward as a whole.
check this link http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2541
What is wrong in my argument?
 
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I'm having trouble visualizing what you are saying. Could you be a little more explicit? Then I, as well as others, would be able to help you.
 
Legaldose said:
I'm having trouble visualizing what you are saying. Could you be a little more explicit? Then I, as well as others, would be able to help you.

here is a picture
http://img191.imageshack.us/img191/3926/lyj9.png

I want to know if the rod will rotate purely or have a translational velocity with rotation?
 
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nil1996 said:
I want to know if the rod will rotate purely or have a translational velocity with rotation?

If the surface is frictionless ,as in the picture,the lower end slips on the surface towards right ,in a manner such that the CM of the rod moves vertically downwards .You can consider the motion of the rod as a combination of translation of CM + Rotation around the CM.

I have made a rough sketch .The red dot shows the CM.
 

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Tanya Sharma said:
If the surface is frictionless ,as in the picture,the lower end slips on the surface towards right ,in a manner such that the CM of the rod moves vertically downwards .You can consider the motion of the rod as a combination of translation of CM + Rotation around the CM.

I have made a rough sketch .The red dot shows the CM.

For the end to slip should there be any net force acting on it?
 
I got it
thanks a lot:smile:
 

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