Physics Cup – TalTech 2025 – Problem 5

By Jaan Kalda (TalTech).

A satellite orbits a planet. At point A, its speed is v_1. At point B, its speed is v_2 and its velocity vector forms a right angle with the velocity vector at point A. At point C, the velocity is exactly opposite to the velocity at point A, with a magnitude of v_3. Find the eccentricity of the orbit. Also determine the exact numerical value of the eccentricity when v_1 = 1km/s, v_2 = 2km/s, and v_3 = 3km/s.

Please submit the solution of this problem via e-mail to physcs.cup@gmail.com. After the publication of the first hint, the base score is reduced to 0.9 pts. For full regulations, see the “Participate” tab.