A Phonograph Turntable, Initially Rotating at 0 $\pi$ C) $\pi$ /40
D) $\pi$

Multiple Choice

A phonograph turntable, initially rotating at 0.75 rev/s, slows down and stops in 30 s. The magnitude of its average angular acceleration in rad/s² for this process is:

A) 1.5
B) 1.5 $\pi$
C) $\pi$ /40
D) $\pi$ /20
E) 0.75