Answer
For elliptical orbit, the total energy can be written as (see Eq. 13-42) $E=-G M m / 2 a,$
where $a$ is the semi-major axis. Thus,
$$
a=-\frac{G M m}{2 E}$$$$=-\frac{\left(6.67 \times 10^{-11} \mathrm{m}^{3} / \mathrm{s}^{2} \cdot \mathrm{kg}\right)\left(5.98 \times 10^{24} \mathrm{kg}\right)(2000 \mathrm{kg})}{2\left(-6.02 \times 10^{10} \mathrm{J}\right)}$$$$=6.63 \times 10^{6} \mathrm{m} .$$
Work Step by Step
For elliptical orbit, the total energy can be written as (see Eq. 13-42) $E=-G M m / 2 a,$
where $a$ is the semi-major axis. Thus,
$$
a=-\frac{G M m}{2 E}$$$$=-\frac{\left(6.67 \times 10^{-11} \mathrm{m}^{3} / \mathrm{s}^{2} \cdot \mathrm{kg}\right)\left(5.98 \times 10^{24} \mathrm{kg}\right)(2000 \mathrm{kg})}{2\left(-6.02 \times 10^{10} \mathrm{J}\right)}$$$$=6.63 \times 10^{6} \mathrm{m} .$$
