For example, when we move/walk, we apply a force (via friction) on earth, and the earth in turn on us. So essentially I see it as an energy transfer as follows:

Suppose I move in same direction as earths rotation. Here I am applying a force in such a way as to increase my velocity from initial $\Omega_{earth} \times radius_{earth}$ , so as to move relative to earth. I also reduce earth's angular rotation during this walking motion due to force I applied on earth. As a whole the system has the same energy.

In light of this, friction doesn't appear as a heat dissipative force to me.

  • $\begingroup$ As long as your feet aren't dragging or sliding, the friction force does no work and no heat is generated. Ask yourself: do tire threads heat up when driving your car? $\endgroup$ – Gert Feb 16 '19 at 23:29
  • $\begingroup$ In light of this, friction doesn't appear as a heat dissipative force to me. Oh but it is: just rub your hands together vigorously for a minute or so! $\endgroup$ – Gert Feb 16 '19 at 23:43
  • $\begingroup$ Friction doesn't just produce heat. Most sliding objects also produce sound, which is acoustic energy leaving the scene. Friction can also cause particles to move. $\endgroup$ – Bill Watts Feb 17 '19 at 0:56
  • $\begingroup$ Static friction does not cause energy dissipation to heat. Only kinetic friction causes such energy dissipation due to the relative movement of the adjacent surfaces. $\endgroup$ – Chet Miller Feb 17 '19 at 2:35
  • $\begingroup$ @Gert I understand exactly what you are getting at when writing *do tire threads heat up when driving a car” but unfortunately? Tires do heat up due to another mechanism - hysteresis. $\endgroup$ – Farcher Feb 17 '19 at 9:18

You are describing static friction. Static friction is not dissipative. It's only when your foot skids on the surface that the friction force becomes sliding or kinetic friction. It is only sliding or kinetic friction that dissipates energy in the form of heat.

Hope this helps.

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