The "Screaming Swing" is a carnival ride that is-not surprisingly—a giant swing. It's actually two swings moving in opposite directions. At the bottom of its arc, a rider in one swing is moving at \(30 \mathrm{~m} / \mathrm{s}\) with respect to the ground in a \(50-\mathrm{m}\)-diameter circle. The rider in the other swing is moving in a similar circle at the same speed, but in the exact opposite direction.

a. What is the acceleration, in \(\mathrm{m} / \mathrm{s}^{2}\) and in units of \(g\), that riders experience?

b. At the bottom of the ride, as they pass each other, how fast do the riders move with respect to each other?