For a small-angle simple pendulum, angular displacement θ is defined to be positive when the bob is displaced clockwise from the lowest point. At an instant when θ=+4∘, state the sign (positive or negative) of (a) the restoring torque about the pivot and (b) the angular acceleration α, and briefly justify each answer.
(a) State the sign (positive or negative) of the restoring torque about the pivot and briefly justify your answer.
(b) State the sign (positive or negative) of the angular acceleration α and briefly justify your answer.