Question

A disk with a radial line painted on it is mounted on an axle perpendicular to it and running through its center. It is initially at rest, with the line at q0 = -90°. The disk then undergoes constant angular acceleration. After accelerating for 3.1 s, the reference line has been moved part way around the circle (in a counterclockwise direction) to qf = 130°.

Given this information, what is the angular speed of the disk after it has traveled one complete revolution (when it returns to its original position at -90°)?

|w| = rad/s

Answer 1

It is not certain to me what the measurement of angles is, and the impact of counterclockwise. It matters.

I assume the displacement was 90+130=220deg . Assuming the other direction would have been 140 deg.

Assuming 220 deg, then

220deg/360deg * 2PI=1/2 angacc*time
solve for angacceleration.

then:
wf^2=2*angacceleration*2PI

watch your units