Question
Physics Question on Newtons law of gravitation
The mass of a spaceship is 1000kg. It is to be launched from the earth's surface out into free space. The value of g and R (radius of earth) are 10m/s2 and 6400km respectively. The required energy for this work will be :
A
6.4??1011 Joules
B
6.4??108 Joules
C
6.4??109 Joules
D
6.4??1010 Joules
Answer
6.4??1010 Joules
Explanation
Solution
W=0−(−RGMm)=RGMm =gR2×Rm=mgR =1000??10??6400??103 =64??109J =64??1010