Chapter: Physics· JEE

The mass of a spaceship is 1000 kg. It is to be launched from the earth’s surface out into free space.

The mass of a spaceship is 1000 kg. It is to be launched from the earth’s surface out into free space. The value of ‘g’ and ‘R’ (radius of the earth) is 10 m/s² and 6400 km respectively. The required energy for this work will be

(a) 6.4 x 10¹⁰Joules

(b) 6.4 x 10¹¹Joules

(d) 6.4 x 10⁹Joules

Doubtly Asked 4 Apr 2021 Student doubt gravitation Save WhatsApp Report

1 answer

Best answer

The correct answer is option (a) 6.4 x 10¹⁰Joules

Explaination ::

The energy required is given by = \(GMm\over R\)

=\( gR^2 \times{ m\over R} (∵ g = {GM\over R2}) \)= mgR

= 1000 x 10 x 6400 x 10³

= 64 x 10⁹ J

= 6.4 x 10¹⁰ J

Doubtly · 4 Apr 2021 Report

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The mass of a spaceship is 1000 kg. It is to be launched from the earth’s surface out into free space.

1 answer

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