The escape velocity from the earth is 11 km/s. The escape velocity from a planet having twice the radius and the same mean density as that of earth is:

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    <p>7. The escape velocity from the earth is 11 km/s. The escape velocity from a planet having twice the radius and the same mean density as that of earth is:</p>

    Question:

    7. The escape velocity from the earth is 11 km/s. The escape velocity from a planet having twice the radius and the same mean density as that of earth is:

    • a) 5.5 km/s
    • b) 11 km/s
    • c) 22 km/s
    • d) None of these

    Answer:

    7. (c) Escape velocity,

    vescape = √((2 GM) / R)

    vescape = R√(8 / 3 πGρ)

    ∴ ve ∝ R if ρ = constant.

    Since the planet has double the radius compared to Earth, the escape velocity becomes twice, i.e., 22 km/s.

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