HUKUM PERGESERAN WIEN FISIKA MODERN PART 1

Introduction

This tutorial provides a comprehensive guide to understanding Wien's displacement law, a fundamental concept in modern physics. Aimed at high school students, particularly those in their senior year, this guide will cover the formulation and application of Wien's law, enhancing your grasp of thermal radiation and its relevance in real-world scenarios.

Step 1: Understanding Wien's Displacement Law

Wien's displacement law states that the wavelength at which the emission of a black body spectrum is maximized is inversely proportional to the absolute temperature of the body.

Key Points:

• Formula: The law can be expressed mathematically as: [ \lambda_{\text{max}} = \frac{b}{T} ] where:

  • ( \lambda_{\text{max}} ) is the wavelength at which emission is maximized,
  • ( b ) is Wien's displacement constant (approximately ( 2898 , \mu m \cdot K )),
  • ( T ) is the absolute temperature in Kelvin.

• Practical Implication: As the temperature of an object increases, the peak wavelength of its emitted radiation shifts to shorter wavelengths.

Step 2: Applying Wien's Displacement Law

To use Wien's law in practical scenarios, follow these steps:

Step 2.1: Determine the Temperature

• Measure the temperature of the object in Kelvin. If you have the temperature in Celsius, convert it using: [ T(K) = T(°C) + 273.15 ]

Step 2.2: Calculate Peak Wavelength

• Use Wien's formula to find the peak wavelength:
  • Input the temperature into the formula: [ \lambda_{\text{max}} = \frac{2898 , \mu m \cdot K}{T} ]

Step 2.3: Interpret the Results

• Analyze the wavelength:
  • If ( \lambda_{\text{max}} ) is in the infrared range, the object emits thermal radiation that is not visible to the human eye (e.g., heated objects).
  • If ( \lambda_{\text{max}} ) falls in the visible spectrum, the object will emit light that can be seen.

Step 3: Real-World Applications

Wien's law has various applications in different fields:

Step 3.1: Astronomy

• Stellar temperatures: By analyzing the light from stars, astronomers can determine their surface temperatures based on the peak wavelength.

Step 3.2: Thermal Imaging

• Infrared cameras: Devices that detect heat and convert it into visible images utilize Wien's law to assess the temperature of objects based on their thermal radiation.

Step 3.3: Climate Science

• Understanding Earth's radiation: Wien's law helps in studying how the Earth radiates heat back into space, which is crucial for climate models.

Conclusion

Wien's displacement law provides valuable insights into the relationship between temperature and radiation. By mastering this law, you can analyze thermal emissions in various contexts, from everyday objects to astronomical bodies. Next, consider exploring further applications of thermal radiation in technology or delving into the Stefan-Boltzmann law for a deeper understanding of black body radiation.