1. What is Radiation Pressure?

Radiation pressure is the mechanical pressure exerted upon any surface due to the exchange of momentum between the object and the electromagnetic field. For gases, it's given by \( P_{rad} = \frac{1}{3} \frac{a T^4}{c} \), where \( a \) is the radiation constant, \( T \) is temperature, and \( c \) is the speed of light.

2. How Does the Calculator Work?

The calculator uses the radiation pressure formula:

Where:

• \( P_{rad} \) — Radiation pressure (Pa)
• \( a \) — Radiation constant (7.5657 × 10^-16 J/m³·K⁴)
• \( T \) — Temperature (K)
• \( c \) — Speed of light (3 × 10⁸ m/s)

Explanation: The formula shows that radiation pressure increases with the fourth power of temperature, making it significant at high temperatures.

3. Importance of Radiation Pressure

Details: Radiation pressure is crucial in astrophysics (stellar dynamics), laser physics, and understanding phenomena like solar sails. It becomes significant in high-temperature environments like stars.

4. Using the Calculator

Tips: Enter temperature in Kelvin (absolute temperature). The calculator will compute the radiation pressure in Pascals.

5. Frequently Asked Questions (FAQ)

Q1: Why is there a 1/3 factor in the formula?
A: The factor accounts for the isotropic nature of radiation in three dimensions.

Q2: When does radiation pressure become significant?
A: At extremely high temperatures (thousands of Kelvin), like those found in stars.

Q3: How does this relate to blackbody radiation?
A: The formula is derived from the energy density of blackbody radiation divided by the speed of light.

Q4: What are typical values for radiation pressure?
A: At room temperature (300K), it's extremely small (~10^-6 Pa). At 5800K (Sun's surface), it's about 0.3 Pa.

Q5: Can radiation pressure do work?
A: Yes, it's the principle behind solar sails that use photon momentum for spacecraft propulsion.