Radiation pressure: The intensity of solar radiation near the earth is 1.4 kW/m². What force is exerted by solar radiation impinging normally on a 5.0 m² perfectly reflecting panel of an artificial satellite orbiting the earth? (c = 3.00 × 10⁸ m/s, μ₀ = 4π × 10^-7 T ∙ m/A, ε₀ = 8.85 × 10^-12 C²/N ∙ m²)

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Quizplus · Accepted Answer

The force exerted by solar radiation on a perfectly reflecting surface is given by $F = \frac{2I A}{c}$, where $I$ is the intensity of the solar radiation, $A$ is the area of the surface, and $c$ is the speed of light. Given $I = 1.4 \, \text{kW/m}^2 = 1400 \, \text{W/m}^2$, $A = 5.0 \, \text{m}^2$, and $c = 3.00 \times 10^8 \, \text{m/s}$, substituting these values gives $F = \frac{2 \times 1400 \times 5.0}{3.00 \times 10^8} = \frac{14000}{3 \times 10^8}$ N. Simplifying this gives $F = 46.67 \times 10^{-6}$ N, or approximately $47 \mu N$.

Radiation Pressure: the Intensity of Solar Radiation near the Earth