# Why friction causes energy to be lost in terms of heat when it appears to be an energy transfer mechanicsm?

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.

• 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? – Gert Feb 16 at 23:29
• 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! – Gert Feb 16 at 23:43
• 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. – Bill Watts Feb 17 at 0:56
• 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. – Chet Miller Feb 17 at 2:35
• @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. – Farcher Feb 17 at 9:18