Sputnik I was launched into orbit around Earth in 1957. It had a perigee (the closest approach to Earth, measured from Earth's center) of 6.81 × 10⁶ m and an apogee (the furthest point from Earth's center) of 7.53 × 10⁶ m. What was its speed when it was at its perigee? The mass of Earth is 5.97 × 10²⁴ kg and G = 6.67 × 10^-11 N ∙ m²/kg². A) 7180 m/s B) 7840 m/s C) 8230 m/s D) 11,000 m/s E) 13,400 m/s

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Quizplus · Accepted Answer

The speed at perigee can be calculated using the vis-viva equation: v = sqrt(GM(2/r - 1/a)), where r is the perigee distance, a is the semi-major axis, and GM is the gravitational parameter. Calculating this gives approximately 7840 m/s.

Sputnik I Was Launched into Orbit Around Earth in 1957