Centroid of a Parametric Curve

Centroid of a Parametric Curve
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2023-06-30 04:38
This GeoGebra worksheet demonstrates the dynamic computation of the centroid (center of mass) of a parametric curve. The centroid is calculated using the formulas \(\bar x = \frac{\int x(t)\,ds/dt\,dt}{L}, \quad \bar y = \frac{\int y(t)\,ds/dt\,dt}{L}\) where \(ds/dt = \sqrt{(dx/dt)^2 + (dy/dt)^2}\). The curve is defined with the CurveCartesian command, the integrals are evaluated numerically by NIntegral, and LaTeX is used to display the formulas. Interactive InputBoxes allow users to change curve parameters a, b, k, while a slider and an animation button animate the parameter t, showing a point moving along the curve and the resulting centroid point C with its coordinates \(\bar x, \bar y\). This example is suitable for high‑school or undergraduate calculus courses, providing a visual and computational insight into the concept of the centroid of a parametric curve.

GeoGebra Commands & Parameters

  1. If(bSketch, tval, b) → tend
  2. Textfield(fx) → InputBox1
  3. Textfield(fy) → InputBox2
  4. Textfield(a) → InputBox3
  5. Textfield(b) → InputBox4
  6. CurveCartesian(fx(t), fy(t), t, a, If[bSketch, tval, b]) → crv
  7. NIntegral(dsdt, a, tend) → L
  8. Textfield(tval) → InputBox6
  9. LaTeX(L, true, true) → text3

AI Drawing Prompt Reference

Draw a parametric curve in the plane, with its centroid dynamically shown. The curve's shape is controlled by three adjustable parameters, which can be changed via input boxes. A slider controls the parameter t, with an animation button to move a point along the curve. The centroid is computed using arc-length integrals, and its coordinates are displayed as a point and text. Also show the total arc length and the centroid formula in LaTeX. The layout should clearly present the curve, moving point, centroid, input boxes, slider, and formula text.
The prompt above was compiled from the original drawing commands and is for reference only.