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 earth) are `10 m//s^(2)` and 6400 km respectively. The required energy for this work will be :

Options

A. `6.4xx10^(10)J`
B. `6.4xx10^(11)J`
C. `6.4xx10^(8)J`
D. `6.4xx10^(9)J`

Answer

A

Explanation

`PE_(i)+KE_(i)=PE_(f)+KE_(f)implies-mgR+KE_(i)=0+0KE_(i)=+mgR=1000xx10xx6.4xx10^(6)`
work done `=6.4xx10^(10)J`