How many Earth radii above the Earth (not from its center) must you be located to experience an acceleration of gravity of 1.38 m/s/s. Express in terms of Earth-radii; that is, express the answer as the number of times greater than 6.38 x 106 m. Ratio of altitude/REarth

It is necessary to be at 2.66 Earth radii to experience an acceleration of  .  

Explanation:          

The height above the earth surface necessary to experience an acceleration of can be found by means of the Universal law of gravity:

 (1)

Then, replacing Newton's second law in equation 3 it is gotten:

 (2)

Then, r can be isolated from equation 2    

 (3)

Where G is the gravitational constant, M is the mass of the Earth and a is the acceleration.                

Hence, it is necessary to be at 2.66 Earth radii to experience an acceleration of  .