Ex-6. A steel tape with a cross-sectional area of 0.039 cm2and weighing 0.909 kg has a length of 30.009 m. when supported throughout 20°C and subject to a tension of 5.5 kg. This tape is used to measure a distance along a uniform 4% grade and is supported throughout during the measurement. The tension applied is 12 kg. The temperature of the tape is 2°C. The measured slope distance is recorded 381.615 m. What is the corrected horizontal distance?

Measuring is the comparison of a particular physical quantity with its reference value. A unit is a fixed physical quantity. The length is a physical quantity. A physical quantity is the product of a unit and the numerical value we need to compare with.