2. Radial and Uniform Fields

Learning Outcomes
  • I can distinguish between radial and uniform gravitational fields.
  • I can describe the field around a planet as a radial field.
  • I can identify situations that approximate uniform fields.
  • I can compare field-line diagrams for different field types.
  • I can explain how field strength changes in radial fields.

Key Topics:
  • Field lines for spherical and planar masses
  • Examples of uniform fields

Comparison Table: Radial vs. Uniform Fields

Feature Radial Field  Uniform Field 
Field Strength () Decreases with r (\( g = \frac{GM}{r^2} \)) Constant (g = 9.81 m/s² near Earth)
Field Lines Point toward the center of mass Parallel and evenly spaced
Force on Objects Weaker at greater distances Constant everywhere
Typical Scale Large-scale (planets, stars, galaxies) Small-scale (Earth’s surface, near objects)
Equation Used g ≈ 9.81 m/s²
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