Block moving on a circular track-Work energy Circular Motion problem

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Homework Help Overview

The problem involves a block of mass 1 kg being pulled by a constant force of 100 N along a smooth circular track with a radius of 10 m. The objective is to find the velocity of the block when it reaches a specific point making an angle of 60 degrees with the vertical. The discussion centers around the work-energy principle and the calculation of work done by the force as the block moves along the circular path.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the nature of the force acting on the block, questioning whether it is truly constant given the changing direction of the tension in the string. There are attempts to clarify how to calculate the work done by the force, with some participants suggesting that the angle between the force and displacement changes continuously.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the problem. Some have provided insights into the relationship between the force, tension, and displacement, while others are seeking clarification on how to properly calculate work done in this context. There is no explicit consensus yet, but productive questions and guidance have been shared.

Contextual Notes

Participants are navigating the complexities of the problem, including the implications of a massless string and the nature of the forces involved. There is a focus on understanding the relationship between the applied force and the resulting tension in the string, as well as the work done on the block during its motion.

  • #31
Tanya Sharma said:
echild...i perfectly understand the first method...regarding second method...work done by pulling force is FL which is work done on the system...but system comprises of block and string wherein string is massless so its mechanical energy is zero .Total energy of system is equal to total energy of block ...?am i right ...this means if the string were having mass then we would not be able to apply the second method?because here

When you calculate the speed of the block, do not forget the work of gravity. The change of KE is equal to the work of all forces...

ehild
 
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  • #32
echild ...thanks a ton... what an explanation...u have made physics enjoyable...i m very very grateful:smile:

thanks to Doc Al ...u were correct but the language confused me...
 
  • #33
Thanks Tania. You are really very kind. I am pleased that you feel Physics enjoyable. It is.
Remember Doc Al sentence: The work done on a system by a force is
The force applied times the displacement of the point of application of that force
. It is very important.

ehild
 
  • #34
ehild said:
Well, have you got that coffee since then? :smile: You totally confused me, so as I deleted my post and had to rewrite it when the example of the simple pulley occurred to me. And I was surprised by the result of the integral method. (I blame it to the hot damp weather here. It is difficult to think.)

ehild
Sorry about that, ehild! And yes, I've been drinking a lot of coffee since then. :-p
 
  • #35
Doc Al said:
Sorry about that, ehild! And yes, I've been drinking a lot of coffee since then. :-p

Take care, too much coffee is bad to hearth. (I also had a coffee since then. :biggrin: )

ehild
 

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