For a rotating body, the angular displacement as a function of time is given by θ(t)=4t2−2t (in radians) for 0≤t≤3s. Which of the following correctly states the angular acceleration and the direction of rotation at t=2.5s? (Take counter-clockwise as positive.)
a) The angular acceleration is +20rad/s2, and the body is rotating counter-clockwise.
b) The angular acceleration is +8rad/s2, and the body is rotating counter-clockwise.
c) The angular acceleration is +8rad/s2, and the body is rotating clockwise.
d) The angular acceleration is −8rad/s2, and the body is rotating counter-clockwise.