🔬 Science & TechnologyUPSC 2006Space & Space Technology

What is the approximate mean velocity with which the earth moves round the sun in its orbit?

a20 km/s ​
b30 km/s
c40 km/s
d50 km/s
✓ Correct answer: b) 30 km/s
ExplanationThe Earth revolves around the Sun in an almost circular orbit.The approximate radius of Earth›s orbit (the average distance from the Sun) is r = 1 Astronomical Unit (AU) = 1.496 × 1011m.The circumference of the orbit will be given by C = 2πr, substituting r = 1.496 × 1011m, we will get C = 9.4 × 1011m.Time taken for one revolution: The Earth takes approximately 1 year to complete one orbit.Time in seconds will be T = 3.156 × 107s.Mean Orbital Velocity: The mean velocity(v) will be given by: v = distance/time, substituting the values: v = 9.4 × 1011m/3.156 × 107s = 29.8 km/s ≈ 30 km/s.216

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