At time t = 0, the arm is rotating about the fixed z-axis with an angular velocity = 200 rad/s in the direction shown.

At time t = 0, the arm is rotating about the fixed z-axis with an angular velocity ω = 200 rad/s in the direction shown. At that time, a constant angular deceleration begins and the arm comes to a stop in 10 seconds. At what time t does the acceleration of point P make a 15° angle with the arm AB?

550 mm P 150 mm B 250 mm