As a result of friction, the angular speed of a wheel c hanges with time according to
d θ = ω0 e-σ t , dt
where ω0 and σ are constants. The angular speed changes from an initial angular speed of 2.67 rad/s to 1.27 rad/s in 3.92 s .
Determine the magnitude of the angular acceleration after 1.39 s.
Answer in units of rad/s2.