1. A 50 m steel tape which had previously been standardized at a tension of 15 kg and at a temperature of 25oC was found to be 0.005m too long. It was used to measure the first 50m athletics field track. The measured length was 49.9915m. When it was measured in winter at a temperature of 10oC and at a tension of 20kg. 
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3. The difference in height between the supports was 0.52m and the base was 480m above mean sea level, where Mean radius of the earth is 6370 Km, Mass of tape is 0.021 kg/m, Cross-sectional area of the tape is 3.21mm2, Young's modulus E is 2.2 * 105 N/mm2 and Coefficient of thermal expansion α is 12 * 10-6/oC. 
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5. Determine the correct length of the field track (show steps).