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I have seen several questions about this on this site and quora and there seems to be no definite, unanimously agreed upon answer. Does static friction do work on an accelerating car.

Heres what i think: Ignoring the affects of air resistance, since the chemical energy of the car is being converted into kinetic energy, some external net force MUST be doing work. Now, although the kinetic energy itself is coming from the chemical energy, the internal engine cant do the work itself as it is not a (external) force. So the static friction is acting as an intermediate, transferring energy?

Would this be analogous to a crate on an accelerating truck. The only horizontal force acting on the crate, ignoring air resistance, is static friction and the crate is moving relative to the earth so static friction must be doing work. But the energy itself is coming from the fuel.

Qmechanic
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Vulgar Mechanick
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  • @chris im sorry but that does not answer my question. Do i need to post this all again? – Vulgar Mechanick Jul 01 '20 at 04:51
  • If the other post doesn't answer your question, just clarify what you are asking that is unanswered by the other post. You can edit this post with the "edit" button underneath, and doing so will automatically put this question into a queue to be considered for reopening. – Chris Jul 01 '20 at 04:56
  • @OVERWOOTCH if u neglect air resistance and assume wheels of the car in pure rolling then there is no need of fule consumption. – Danny LeBeau Jul 01 '20 at 05:42
  • Umm what? How is the kinetic energy of the “accelerating car. Changing? Where is the kinetic energy coming from – Vulgar Mechanick Jul 01 '20 at 05:52
  • A car can't pure roll forever .Kinetic energy indeed comes from fuel consumption. But if there is no air resistance the KE of the car remains constant (when already experiencing $f_{max}$)as car can move forever without any opposing force. – Danny LeBeau Jul 01 '20 at 06:46
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    I believe your suggested explanation is accurate. Static friction does the work as an intermediate. It is a mean of transferring the energy from the stored version to the kinetic version, in the form of work. – Steeven Jul 01 '20 at 06:56

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