A Wheel Rotating About a Fixed Axis Has a Constant

Multiple Choice

A wheel rotating about a fixed axis has a constant angular acceleration of 4.0 rad/s2. In a 4.0-s interval the wheel turns through an angle of 80 radians. Assuming the wheel started from rest, how long had it been in motion at the start of the 4.0-s interval?

A) 2.5 s
B) 4.0 s
C) 3.5 s
D) 3.0 s
E) 4.5 s