A high-altitude scientific research balloon carries an instrument capsule designed to operate in the stratosphere where temperatures can drop to −60∘C-60^\circ\text{C}−60∘C.
During a simulation test inside a thermal chamber, a thermal infrared camera is used to image the capsule. In the resulting thermal image:
Knowing that darker shades represent lower temperatures, discuss what information this thermal image gives about the temperatures of these different regions.
The outer insulation of the capsule is composed of double-walled panels filled with a low-density silica aerogel containing microscopic pockets of trapped nitrogen gas.
Explain how this structure reduces thermal energy transfer by conduction and convection.
Underneath the aerogel layer, the capsule's inner structural wall is painted matte black, while the inner surface of the outer protective shell is highly polished and silvered. Explain how the combination of a matte black inner wall and a reflective silvered outer surface reduces the overall rate of thermal energy loss from the capsule's warm interior.
36 exam-style questions on Edexcel IGCSE Physics Energy transfers. Each one has a worked solution and a mark scheme showing where the marks go.