## Essential University Physics: Volume 1 (4th Edition) Clone

We know that the necessary centripetal force must equal the force of friction. Thus: $\frac{mv^2}{r} = \mu_s mg \\ v = \sqrt{\mu_s gr}$ Thus, we find: a) $v_{max} = \sqrt{\mu_s gr} = \sqrt{.21\times9.81\times73} = 12 \ m/s$ b) $v_{max} = \sqrt{\mu_s gr} = \sqrt{.88\times9.81\times73} = 25 \ m/s$