Step 1: Formula.
\[
v_e=\sqrt{\frac{2GM}{R}}.
\]
Step 2: Substitute (SI).
\[
R=3390\times10^3\ \text{m},\
v_e=\sqrt{\frac{2(6.67\times10^{-11})(6.4169\times10^{23})}{3390\times10^3}}
=5025\ \text{m/s}\approx 5.03\ \text{km/s}.
\]
\[
\boxed{5.0\ \text{km/s}}
\]
F and G denote two points on a spacecraft’s orbit around a planet, as indicated in the figure. O is the center of the planet, P is the periapsis, and the angles are as indicated in the figure. If \( OF = 8000 \, {km} \), \( OG = 10000 \, {km} \), \( \theta_F = 0^\circ \), and \( \theta_G = 60^\circ \), the eccentricity of the spacecraft's orbit is __________ (rounded off to two decimal places).
F and G denote two points on a spacecraft’s orbit around a planet, as indicated in the figure. O is the center of the planet, P is the periapsis, and the angles are as indicated in the figure. If \( OF = 8000 \, {km} \), \( OG = 10000 \, {km} \), \( \theta_F = 0^\circ \), and \( \theta_G = 60^\circ \), the eccentricity of the spacecraft's orbit is ___________ (rounded off to two decimal places).
