Question

At which height from the earth's surface does the acceleration due to gravity decrease by 75% of its value
at earth's surface ?​

Answer 1

Answer:

Acceleration due to gravity at height h from earth surface is:

g

′

=g(1−

R

2h

)

g

g

′

=(1−

R

2h

)

100

75

=(1−

R

2h

)

100

25

=

R

2h

h=

8

R

=

8

6.4×10

6

=8×10

5

m=800km

Thus, at 800km above earth surface g becomes 75% of its value on earth surface