No Work Done during Circular Motion

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SUMMARY

In circular motion, no work is done because the force acting on the object is always perpendicular to the displacement vector. The formula for work done, W = F x d x cos(θ), indicates that when θ equals 90 degrees, the work done is zero. The discussion emphasizes that in circular motion, the velocity vector remains constant in direction, reinforcing that the displacement is always perpendicular to the centripetal force. Thus, regardless of the velocity's magnitude, the work done remains zero.

PREREQUISITES
  • Understanding of basic physics concepts such as force, displacement, and work.
  • Familiarity with the principles of circular motion.
  • Knowledge of vector addition and directionality in physics.
  • Basic grasp of trigonometric functions, particularly cosine.
NEXT STEPS
  • Study the principles of centripetal force in circular motion.
  • Learn about the relationship between force and displacement in different motion types.
  • Explore the implications of work-energy theorem in various physical scenarios.
  • Investigate the role of angular velocity in circular motion dynamics.
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Students of physics, educators teaching mechanics, and anyone interested in understanding the dynamics of circular motion and work-energy principles.

Peter G.
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Hi guys, :smile:

Work Done = Force x Distance x cos of Theta - the angle between the Force and the Displacement Vector / direction of motion

In Circular motion I know the force but I am given velocity. In order to prove that no work is done is it correct to say the following:

If we have two velocities, one horizontal and another vertical and find the resultant, the direction of the resultant velocity will be the direction of the displacement vector.

Hence, in circular motion, we only have one velocity vector, we don't need to add. We can then consider it to be the direction of the displacement vector - this would always be at 90 degrees to the force making me understand that no work is done.

Thanks,
Peter G.
 
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Ok, so I will try and make my point clearer: Check the attachment.
 

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