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Problem 2 (5 pts). A blackbelt in karate chops a board in half with her hand. Just before contacting the board, the forearm has a rotational speed of 40 rad/s. Just after breaking the board, the forearm has a rotational speed of 20 rad/s. The board breaks in 0.004 s. Her fist is 0.32 m from her elbow joint and the rotational inertia of her forearm is 0.050 kg\text{m}^2. a. [2 pts] What is the rotational acceleration of her forearm while in contact with the board? Assume the rotational acceleration is constant during this time. b. [3 pts] Draw an extended force diagram for her forearm and determine the average force her hand exerts on the board while breaking it. You may assume that the force that the board exerts on the hand is much larger than any other forces on the hand/forearm and so these other forces can be neglected.

          Problem 2 (5 pts). A blackbelt in karate chops a board in half with her hand. Just before contacting the board, the forearm has a rotational speed of 40 rad/s. Just after breaking the board, the forearm has a rotational speed of 20 rad/s. The board breaks in 0.004 s. Her fist is 0.32 m from her elbow joint and the rotational inertia of her forearm is 0.050 kg\text{m}^2. a. [2 pts] What is the rotational acceleration of her forearm while in contact with the board? Assume the rotational acceleration is constant during this time. b. [3 pts] Draw an extended force diagram for her forearm and determine the average force her hand exerts on the board while breaking it. You may assume that the force that the board exerts on the hand is much larger than any other forces on the hand/forearm and so these other forces can be neglected.

Problem 2 (5 pts). A blackbelt in karate chops a board in half with her hand. Just before contacting the board, the forearm has a rotational speed of 40 rad/s. Just after breaking the board, the forearm has a rotational speed of 20 rad/s. The board breaks in 0.004 s. Her fist is 0.32 m from her elbow joint and the rotational inertia of her forearm is 0.050 kgm^2. a. [2 pts] What is the rotational acceleration of her forearm while in contact with the board? Assume the rotational acceleration is constant during this time. b. [3 pts] Draw an extended force diagram for her forearm and determine the average force her hand exerts on the board while breaking it. You may assume that the force that the board exerts on the hand is much larger than any other forces on the hand/forearm and so these other forces can be neglected.

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