Question

the distance of the centre of moon and earth is D. the mass of earth is 81 times the mass of the moon. at what distance from the centre of the earth , the gravitational intensity will be zero​

Answer 1

Answer:

Lets assume there is a particle of mass m from x  distance away from earth. assuming gravitational force on m is zero so :-.

Force balance

x  

2

 

(Gm81M)

​  

 =  

(d−x)  

2

 

(GmM)

​  

 

x  

2

 

81

​  

 =  

(d−x)  

2

 

1

​  

 

9

x

​  

 =  

1

d−x

​  

 

solving above wquation we will get

x=  

10

9d

​

Explanation