Torque and rotational motion

Answer

The **angle turned per second** — the rate of change of θ. Unit: **rad s⁻¹**.

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The **rate of change of angular velocity** ω. Unit: **rad s⁻²**.

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The angle whose **arc length equals the radius**. A full turn = **2π rad = 360°**.

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Slope = **angular acceleration** α; area = **angle turned** θ.

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$\omega = \omega_0 + \alpha t$.

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Multiply by **2π** (one revolution = 2π rad).

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The **turning effect** of a force: $\tau = Fr\sin\theta$. Unit: **N m**.

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When it acts **through the pivot** (θ = 0, sin θ = 0).

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The **total torque about any point is zero** (clockwise = anticlockwise).

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A point on an **unknown force's line**, so that force has zero torque.

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Bigger **r** → bigger torque for the same force.

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Both are N m, but torque is **N m** (a turning effect); energy is the **joule**.