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Question :
36. A baseball pitcher loosens up his pitching arm. He : 2102173

36. A baseball pitcher loosens up his pitching arm. He tosses a 0.15-kg ball using only the rotation of his forearm, 0.32 m in length, to accelerate the ball. If the ball starts at rest and is released with a speed of 12 m/s in a time of 0.40 s, what torque is applied to the ball while being held by the pitcher's hand to produce the angular acceleration?

A. 1.1 N?m

B. 11 N?m

C. 7.2 N?m

D. 1.4 N?m

37. A bucket of water with total mass 23 kg is attached to a rope, which in turn is wound around a 0.050-m radius cylinder at the top of a well. A crank with a turning radius of 0.25 m is attached to the end of the cylinder and the moment of inertia of cylinder and crank is 0.12 kg?m^{2}. If the bucket is raised to the top of the well and released, what is the acceleration of the bucket as it falls toward the bottom of the well? (Assume rope's mass is negligible, that cylinder turns on frictionless bearings and that *g* = 9.8 m/s^{2}.)

A. 3.2 m/s^{2}

B. 6.3 m/s^{2}

C. 7.4 m/s^{2}

D. 9.8 m/s^{2}

38. A bucket of water with total mass 23 kg is attached to a rope, which in turn is wound around a 0.050-m radius cylinder at the top of a well. The bucket is raised to the top of the well and released. The bucket is moving with a speed of 8.0 m/s upon hitting the water surface in the well. What is the angular speed of the cylinder at this instant?

A. 39 rad/s

B. 79 rad/s

C. 120 rad/s

D. 160 rad/s

39. A majorette takes two batons and fastens them together in the middle at right angles to make an "x" shape. Each baton was 0.80 m long and each ball on the end is 0.20 kg. (Ignore the mass of the rods.) What is the moment of inertia if the arrangement is spun around an axis formed by one of the batons?

A. 0.048 kg?m^{2}

B. 0.064 kg?m^{2}

C. 0.19 kg?m^{2}

D. 0.32 kg?m^{2}

40. A majorette takes two batons and fastens them together in the middle at right angles to make an "x" shape. Each baton was 0.80 m long and each ball on the end is 0.20 kg. (Ignore the mass of the rods.) What is the moment of inertia if the arrangement is spun around an axis through the center perpendicular to both rods?

A. 0.064 kg?m^{2}

B. 0.096 kg?m^{2}

C. 0.13 kg?m^{2}

D. 0.32 kg?m^{2}