Question 1: What is meant by 'emission' in the context of black body radiation?

Answer: Emission refers to the release of electromagnetic radiation from a hot object due to its thermal energy.

Question 2: Explain why objects in space, such as stars and planets, emit radiation.

Answer: Objects in space emit radiation because they have thermal energy that causes them to emit electromagnetic waves as part of black body radiation.

Question 3: Define 'black body' and its significance in studying emission.

Answer: A black body is an idealized object that absorbs all incident radiation and emits a characteristic spectrum based on its temperature, used as a standard for studying emission.

Question 1: A space telescope detects infrared radiation at a wavelength of 10 micrometers emitted by a distant star. If the temperature of the star's surface follows Wien's Law, calculate its approximate temperature. (Wien's Law: λ_max * T = 2.898 x 10^-3 m·K)

Answer: T = (2.898 x 10^-3 m·K) / (10 x 10^-6 m) = 289.8 K

Question 2: A planet emits thermal radiation with a power of 5 x 10^22 watts. If its surface temperature is 300 K, what is the approximate surface area of the planet? (Use Stefan-Boltzmann Law: P = σ * A * T^4, where σ = 5.67 x 10^-8 W/m^2·K^4)

Answer: A = P / (σ * T^4) = (5 x 10^22 W) / (5.67 x 10^-8 W/m^2·K^4 * (300 K)^4) ≈ 4.6 x 10^16 m^2

Question 1: Describe an experimental setup to measure the emission spectrum of a heated metal filament in space simulation conditions. Include the key variables and safety precautions.

Answer: The setup includes a vacuum chamber with a heated filament connected to a power supply, a spectrometer to analyze emitted radiation, and sensors to monitor temperature. Variables include filament material, temperature, and ambient pressure. Safety precautions involve handling high voltages, ensuring proper insulation, and operating within a controlled environment to prevent accidents.

Question 1: A space probe's thermal imaging system detects that a planet's surface emits predominantly in the infrared region with a peak wavelength of 8 micrometers. Based on this data, estimate the surface temperature of the planet using Wien's Law.

Answer: T = (2.898 x 10^-3 m·K) / (8 x 10^-6 m) = 362.25 K

Question 2: Explain how understanding emission and black body radiation helps in designing thermal control systems for spacecraft.

Answer: Understanding emission allows engineers to predict how spacecraft surfaces radiate heat, enabling the design of thermal control systems that manage temperature by controlling emission and absorption of radiation, ensuring safe and efficient operation in space.