The mass of space ship is 2000 kg. It is launched from the earth’s surface out into free space. The value of ‘g’ and ‘R’ are $10{\text{m/sec}}^{\text{2}}$ and 6400 km. The required energy for this work will be

$m=2000\text{kg},g=10{\text{m/sec}}^{\text{2}},R=6400\text{km}=64\times {10}^5\text{m}$ 

Where$m=$ Mass of space ship

$R=$ Radius of earth

Required energy work $=\frac{GMm}{R}\left(\because g=\frac{GM}{R^2}\right)$

Where $G=$ Gravitational constant

$W=mgR(\because gR=\frac{GM}{R})$

$\therefore W=mgR=2000\times 10\times 64\times {10}^5$

$=128\times {10}^9$

$=12.8\times {10}^{10}J$