Justhin and Christian have masses of 74 kg and 64 kg, respectively. They stand 0.5 m apart. If there were no other forces acting on them, what gravitational force would they be exerting on each other?

ans: 1.26 × 10^(-6) N

Explanation:

suppose that;

mass of Justhin ( m) = 74 kg

mass of Christian (M) = 64 kg

distance of separation (d) = 0.5 m

universal gravitational constant(G) =6.67 × 10^(-11) Nm²/kg²

so,

gravitational force between them(F) = GmM/d²

F = (6.67 × 74× 64)/ ( 10¹¹× 0.5²)

= (1.26 × 10⁵)/ 10¹¹

= 1.26 × 10^(-6) N

the working equation for the angular size is the product of the physical size and 360 degrees divided by the product of two pi and distance from earth. the minimum size would be 0.559 degrees while the maximum size would be 0.49 degrees. 

c. newton's third law of motion