Question

show that acceleration due to gravity decrease with altitude.At what height above the earth surface the acc. due to gravity will be 1/9 of its value at the earth surface

Answer 1

At which height from earth surface acceleration due to gravity is decreased by 1%?

We know that gravity at any height is given as;

g’ = g (1 - 2h/R) —[1]

Decrease by 1% implies that g’ = 99/100g

Substitute In 1,we get

99/100g = g (1 - 2h/R)

99/100 = 1 - 2h/R

2h/R = 1 - 99/100

2h/R = 1/100

h = R/200

h = 6400/200 (R = 6400KM)

H = 32KM From surface of earth