Learning objectives
- Measure rotation relative to a starting orientation.
- Convert degrees, radians and revolutions.
- Distinguish signed angular displacement from total angular distance.
- Connect radius, angle and arc length.
Key concepts
Δθ = θ − θ₀ uses a continuous, unwrapped angle. One full turn is 2π radians or 360°. Counterclockwise is positive here.
Arc length = radius × angle in radians for a single-direction sweep. Total path length uses total angular distance. Two points on one rigid object share angular displacement and angular velocity, but their path lengths differ with radius.
The inner point has half the outer radius. The angle sector shows the current partial turn (or one full turn at exact multiples). It cannot depict every completed turn at once; use the signed readout to see the accumulated history.
Motion has prescribed constant angular velocity until you reverse or change it. No torque or acceleration model is included. Narration slows the visible motion for observation; the physical simulation clock and equations stay consistent.