Applying work energy theorem to unifrom circular motion

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SUMMARY

The discussion focuses on deriving the equation of centripetal acceleration using the work-energy theorem in the context of uniform circular motion. The key equation derived is F = mv^2/2R, where F represents the centripetal force, m is mass, v is velocity, and R is the radius of the circular path. A critical error identified is the misunderstanding that work is done in uniform circular motion, as the force and displacement are perpendicular, resulting in zero work. Additionally, kinetic energy is clarified as a scalar quantity, not a vector.

PREREQUISITES
  • Understanding of the work-energy theorem
  • Knowledge of uniform circular motion principles
  • Familiarity with centripetal acceleration concepts
  • Basic grasp of kinetic energy as a scalar quantity
NEXT STEPS
  • Study the relationship between centripetal force and acceleration in uniform circular motion
  • Explore the implications of the work-energy theorem in non-linear motion
  • Learn about the role of angular momentum in circular motion
  • Investigate the differences between scalar and vector quantities in physics
USEFUL FOR

Students studying physics, particularly those focusing on mechanics, educators teaching circular motion concepts, and anyone preparing for exams involving the work-energy theorem and centripetal acceleration.

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Homework Statement


attempt to derive the equation of centripetal acceleration using work energy theorem

Homework Equations



work done = Change in kinetic energy

The Attempt at a Solution



consider diametrically opposed points occurring in uniform circular motion - displacement = 2*R and let force be denoted by F

By work energy theorem ; F*2R = 1/2mv^2 - (-1/2mv^2)
F = mv^2/2R

...
So close...
Where did I go wrong
 
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In uniform circular motion, the force and displacement are always at right angles--no work is done.
 
Also, kinetic energy is not a vector. It is incorrect to say that kinetic energy is positive when the mass is moving in one direction and negative when moving in the opposite direction.
 

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