Newton's Second Law for Rotation
Topic 5.5 was about when a body's rotation doesn't change: $\sum\tau = 0$. Topic 5.6 is what happens when the torques don't cancel. The body angularly accelerates, and the size of $\alpha$ is set by the rotational version of Newton's second law: $\sum\tau = I\alpha$. Same shape as $\sum F = m a$, with rotational inertia $I$ in place of mass.
The lesson closes by knocking down three traps. Confusing constant net torque with constant $\omega$ (constant $\tau$ actually gives constant $\alpha$, so $\omega$ grows steadily). Reading "same mass" as "same $I$", since distribution matters as much as total mass. And at the turnaround of a swing, concluding $\alpha = 0$ from $\omega = 0$, which $\sum\tau = I\alpha$ never says.
The work
3 ways in · any order
Lesson
Newton's Second Law for Rotation
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Build $\sum\tau = I\alpha$ as Newton's second law for rotation. Two worked examples: a rod released from horizontal, and a pulley with a hanging mass. Ten-scenario applet hits the $\omega$ vs $\alpha$ confusion, the zero-$\omega$-means-zero-$\alpha$ trap, and the mass-distribution effect on $\alpha$.
Diagnostic
10-item topic check
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Ten multiple-choice items mapped to the misconception traps active in this topic. Each wrong answer is tied to a specific failure mode, so a miss tells you exactly which trap fired.
Targeted Practice
Drill a single misconception
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Pick one of the failure modes you've missed and grind it on its own. The round is adaptive: two correct in a row clears the misconception and you move on.