While punting a football, a kicker rotates his leg about the hip joint. The moment of inertia of the leg is 3.75 kg ? m2 and its rotational kinetic energy is 175 J. (a) What is the angular velocity of the leg? (b) What is the velocity of tip of the punter’s shoe if it is 1.05 m from the hip joint? (c) Explain how the football can be given a velocity greater than the tip of the shoe (necessary for a decent kick distance).
Step-by-step solution Step 1 of 4 The rotational kinetic energy of the leg is given as, Where, I is the moment of inertia of the leg and is the angular velocity. Step 2 of 4 (a) The moment of inertia of the leg is given as, Also the rotational kinetic energy of the leg is given as, The angular velocity from above is, Substitute and 175 J for . Hence, the angular velocity is .