Doc Brown is prepping the DeLorean for time travel. (You have seen Back to the Future, I hope!) In order to time travel, the Delorean must hit
88mph, or 39.34 m/s. The DeLorean can achieve an acceleration of 9.0
m/s^2. What is the minimum open space needed for the DeLorean to
successfully initiate time travel? *

Suppose a wheel with a tire mounted on it is rotating at the constant rate of 2.15 times a second. a tack is stuck in the tire at a distance of 0.373 m from the rotation axis. noting that for every rotation the tack travels one circumference (a) find the tack's tangential speed. (b) what is the tacks radial acceleration?