Question

The height above the surface of earth at which the gravitational field intensity is reduced

Answer 1

Answer:

This occurs at a distance of 7.3×106 m from the centre of the Earth (which is 900 km from the surface).

Explanation:

Are we okay to start from the field equation for the Earth's gravitational field?

g=GMr2 where M is the mass of the Earth.

What you do now, is change the subject of this equation so it solves for r:

r=√GMg

Plug in the numbers, and you have it!

r=√(6.67×10−11)(5.98×1024)7.5

= 7.3×106 m

(By the way, since this value is from the centre of the Earth, and the radius of the Earth is 6.4×106 m, we are looking at a point only 900 000 m (900 km) above the surface of the Earth.)