An astronaut is being tested in a centrifuge. The centrifuge has a radius of 10 m and, in starting, rotates according to ? = 0.30t2, where t is in seconds and ? is in radians. (a) When t = 15.0 s, what is the magnitude of the astronaut's angular velocity? (b) When t = 15.0 s, what is the magnitude of the astronaut's linear speed? (c) When t = 15.0 s, what is the magnitude of the astronaut's tangential acceleration?(d) When t = 15.0 s, what is the magnitude of the astronaut's radial acceleration?