JEE Mains · Physics · STD 11 - Gravitation
- JEE Mains 2021
- Hard
- MCQ
The masses and radii of the earth and moon are \(\left({M}_{1}, {R}_{1}\right)\) and \(\left({M}_{2}, {R}_{2}\right)\) respectively. Their centres are at a distance ' \({r}\) ' apart. Find the minimum escape velocity for a particle of mass ' \({m}\) ' to be projected from the middle of these two masses:
Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \({V}=\sqrt{\frac{4 {G}\left({M}_{1}+{M}_{2}\right)}{{r}}}\)
Step-by-step Solution
Detailed explanation
\(\frac{1}{2} {mV}^{2}-\frac{{GM}_{1} {m}}{{r} / 2}-\frac{{GM}_{2} {m}}{{r} / 2}=0\)
\(\frac{1}{2} {mV}^{2}=\frac{2 {Gm}}{{r}}\left({M}_{1}+{M}_{2}\right)\)
\({V}=\sqrt{\frac{4 {G}\left({M}_{1}+{M}_{2}\right)}{{r}}}\)
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