A missile weighing 400N on the earth surface is shot into the atmosphere to an altitude of 6.4 x (10^{-6})m. Taking the earth as a sphere of radius 6.4 x (10^{-6})m and assuming the inverse-square law of universal gravitation, what would be the weight of the missile at that altitude?
-
A.
100N -
B.
200N -
C.
400N -
D.
800N -
E.
1600N
Correct Answer: Option A
Explanation
W=(frac{mg}{4}= frac{400}{4}=100N)