When a Fan Is Turned Off, Its Angular Speed Decreases $0,74 \mathrm { rad } / \mathrm { s } ^ { 2 }$

Multiple Choice

When a fan is turned off, its angular speed decreases from 10 rad/s to 6.3 rad/s in 5.0 s. What is the magnitude of the average angular acceleration of the fan?

A) $0,74 \mathrm { rad } / \mathrm { s } ^ { 2 }$
B) $1.2 \mathrm { rad } / \mathrm { s } ^ { 2 }$
C) $11 \mathrm { rad } / \mathrm { s } ^ { 2 }$
D) $0.37 \mathrm { rad } / \mathrm { s } ^ { 2 }$
E) $0.86 \mathrm { rad } / \mathrm { s } 2$