A disk is free to rotate about a vertical axis through its center

PHYSICS · Single correct · AP · Physics 1: Algebra-based · Energy and Momentum of Rotating Systems · Energy and Momentum of Rotating Systems

Problem

A disk is free to rotate about a vertical axis through its center. A constant net external torque of

2.0\,\text{N}\cdot\text{m}

acts clockwise on the disk for

4.0\,\text{s}

. Which of the following is most consistent with the effect of this torque on the disk’s angular momentum? (a)

\Delta L = 8.0\,\text{N}\cdot\text{m}\cdot\text{s}

in the counter-clockwise direction (b)

\Delta L = 0.50\,\text{N}\cdot\text{m}\cdot\text{s}

in the clockwise direction (c)

\Delta L = 8.0\,\text{N}\cdot\text{m}\cdot\text{s}

in the clockwise direction (d)

\Delta L = 4.0\,\text{N}\cdot\text{m}\cdot\text{s}

in the clockwise direction