Answer:
[tex]v = 3.5 \times 10^5 m/s[/tex]
Explanation:
At some distance from the Earth the force of attraction due to moon is balanced by the force due to Moon
so we will have
[tex]\frac{GM_em}{r^2} = \frac{GM_m}{(d-r)^2}[/tex]
now we have
[tex]\frac{d - r}{r} = \sqrt{\frac{M_m}{M_e}}[/tex]
[tex]\frac{3.844\times 10^8 - r}{r} = \sqrt{\frac{7.36 \times 10^{22}}{5.9742\times 10^{24}}}[/tex]
so we will have
[tex]r = 3.46 \times 10^8 m[/tex]
Now by energy conservation
[tex]-\frac{GM_e}{R_e} - \frac{GM_m}{d - (R_e + R_m)} + \frac{1}{2}v^2 = -\frac{GM_e}{r} - \frac{GM_m}{d - r}[/tex]
[tex]-6.26 \times 10^{8} - 13046 + \frac{1}{2}v^2 = -1.15 \times 10^6 - 1.28 \times 10^5[/tex]
[tex]v = 3.5 \times 10^5 m/s[/tex]