Gravity by John Mayer

 

C) Universal Law of Gravity

 

 

 

Moon has Unbalanced Force On It!

 

Gravity - mutual force of attraction between any two objects in the universe

F= Gm1m2
r2

G=Gravitational constant=6.67 x 10-11 Nm2/kg2

(Reference Table p. 1)

 

m1, m2  two masses

 

r - distance between center of masses

 

 

Fg proportional to product of two masses

 

Fg m1 m2
100 N x

 
              
 y



200 N
2x



y



600 N
2x



3y




400 N
x



4y





150 N
1/2x


x3



F = Gm1m2
r2

 

 

Fg inversely proportional to the square of distance between the object's center of mass

 

 

 

Fg r



x1/4
x2





x1/9
x3





x1/16
x4





x9
x1/3





x16
x1/4


 

Ex) If the gravitational force on satellite A is 160,000 N, what is the gravitational force on satellite B?

 

 

 

F = 40,000 N - twice the distance 1/4 the force