HELP! Pysics test tomorrow

[acoult]

[o)] Hello anyone that can help. I am trying to gain an understanding of rotational motion, including (tangential speed, angular momentum, centripetal force and so on). The first question I was hoping that someone could help me is:

An automobile speedometer is configured yo read speed proportional to the rotational speed of its wheels. If larger wheels are used, will the speedometer reading be higher, lower or the same.



I understand the question but I was hoping someone could help explain this to me in a mathamatical equation.


Thank you for your help. I promise not to bug you guys to much!

[Ambitwistor]

An automobile speedometer is configured yo read speed proportional to the rotational speed of its wheels. If larger wheels are used, will the speedometer reading be higher, lower or the same.

The question is slightly ill-posed, since it didn't specify what is kept the same when the wheels are changed. But I assume they mean that the ground speed of the automobile is kept the same. The ground speed is the same as the tangential speed v of a point on the wheel. By v = R\omega, the rotational speed ω must decrease if R increases, if we hold v constant.