Consider the following diagram of the knee joint during the landing in a sprinting movement of a 60 kg individual with a leg of length 0.30 meters. The knee joint is flexed to 155 degrees. The quadriceps muscle produces 500 newtons of force and insert at a distance of 0.05 meters from the knee joint. The weight of the thigh acts from the center of gravity of the thigh, a distance of 0.21 meters from the knee joint, and produces a flexion torque. The gastrocnemius muscle can produce 600 newtons of force and inserts at a distance of 0.07 meters from the knee joint and would produce a flexion torque. What is the resultant angular acceleration of the knee in this example?