Friction Paradox: The Mystery of Constant Speed Motion

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    Friction Paradox
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SUMMARY

The discussion centers on the friction paradox as described in Derek Raine's mechanics book. It explores the scenario where a block moves at constant speed, with friction balancing the external force, leading to heat dissipation. When an observer runs alongside the block, they perceive the block as stationary, seemingly eliminating the need for energy input. However, it is clarified that the observer is still expending energy to move relative to the ground, thus not removing the energy requirement.

PREREQUISITES
  • Understanding of Newtonian mechanics
  • Familiarity with the concept of friction
  • Knowledge of reference frames in physics
  • Basic principles of energy conservation
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  • Study the principles of Newton's laws of motion
  • Explore the concept of reference frames in classical mechanics
  • Investigate the thermodynamics of friction and heat dissipation
  • Examine energy conservation in different physical systems
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Students of physics, educators teaching mechanics, and anyone interested in the nuances of motion and energy in classical mechanics.

VVS2000
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I was reading this book on mechanics by derek raine and came up on something called friction paraddox.
Suppose a block is is moving with constant speed and the external force is balanced by friction. We know friction causes heat dissipation and the external force supplies some energy so as to keep the speed constant.suppose I run along with the block at same speed and with respect to me, block is in rest and there is no heat dissipation. So how come I have beem able to remove the need for supplying energy just by changing my frame of reference? Thanks in advance!
 
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VVS2000 said:
So how come I have beem able to remove the need for supplying energy just by changing my frame of reference?
You haven't. In your frame of reference you are expending energy to move the floor under you.
 
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