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Here is a summary of the text from the document: The text contains a series of questions, likely from a science or physics test. These questions involve calculations and concepts related to solar energy, spacecraft, and physics. The problems ask about the thrust of a solar sail spacecraft, the temperature increase in a heater coil, and include questions about physics applications related to space exploration and heating elements. If you need help with specifics or solving any questions from the document, feel free to ask!