physics answers test 2

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2.1 J

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3

The block, because it does not gain rotational kinetic energy, but the sphere does

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1:1

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The angular impulse is 0

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7

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  The torque increases in magnitude and is in the opposite direction of the angular momentum.

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      B: Constant & Decreasing

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·         No, because the torques exerted on the rod and the disk are internal to the system.

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 The cube, because the cube’s kinetic energy will all be in the form of translational kinetic energy, while some of the sphere’s kinetic energy will be in the form of rotational kinetic energy.

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2.5 S

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B, A, C

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·         The child moves toward the center of the platform, decreasing the rotational inertia of the system.

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