Question

At what height from the surafce of earth will the value of g reduced by 75% from the value at the surface ( radius of earth =6400)

Answer 1

g at height is g(r/r plus h)

g at h is 3/4g equal to g(6400/6400 plus h)^2

square root the both side

root 3/2equal to 6400/6400 plus

root3(6400 plus h) equal to6400 *2

1.732(6400 plus h) equal to 12800

11084.8 plus1.732h equal to 12800

1.732h equal to 1715.2

h is equal to 990.30m