Question

Force of attraction between two bodies varies inversely with square of distance be-

tween them. When these bodies are 2 feet away, the force is 45[N]. Find the force when

the distance is 3 feet​

Answer 1

Answer:

applying formula

F=G m1×m2/r^2

45=G×m1×m2/2^2

45×4=Gm1m2

180=Gm1m2.....(1)

now when r=3

F=Gm1m2/3^2

F=180/9 ( from eq 1)

F=20N

Answer 2

The force between the bodies when the separation is 3m is 20N.

Given: force between these bodies when they are 2m apart (F1)= 45N

The initial distance between the bodies(d1) = 2m

Final distance between the bodies(d2) = 3m

Force of attraction between two bodies varies inversely with the square of the distance

To Find: The final force between the bodies

Solution:

Since the force of attraction is inversely proportional to the square of the distance between the bodies

F = k/x², where F is the force between the bodies, k is a universal constant and x is the distance between the bodies.

F1 = k / (2) ²                    

45 = k / (2) ²                       ..1

F2 = k / (3) ²                      ..2

Divide equation 1 by equation 2

45/ F2  = 9 / 4

F2 = 4 x 5

     = 20

Therefore, the force between the bodies when the separation is 3m is 20N.