CIE iGCSE Co-Ordinated Science P6.2.1 The Sun as a star Exam Style Questions Paper 2

Orbital speed is calculated using \(v = \frac{2\pi r}{T}\). First, convert the orbital period from hours to seconds: \(7.7 \, \text{hours} \times 3600 \, \text{s/hour} = 27720 \, \text{s}\). Substituting the values: \(v = \frac{2\pi (9.4 \times 10^6)}{27720} \approx \frac{5.905 \times 10^7}{27720} \approx 2.13 \times 10^3 \, \text{m/s}\). This rounds to \(2.1 \times 10^3 \, \text{m/s}\).
✅ Answer: (B)