A skater holds her arms outstretched as she spins at 180 rpm.
180rpm = 3 rotations per second
i.e. 3 x 360 degrees per second
=1080 degrees a second.
i rotation is equivalent to travelling 2 x 3.14 x 70 (as radius of rotational motion is 140/2 = 70cm)
that is equal to 439.6cm
therefore distance travelled in 1 second = 4.39m x 3=13.188m/s