A 1 kg object is located at a distance of 1.0 x 103 m from the center of a larger object whose mass is 2.0 x 1020 kg.
a. What is the size of the force acting on the smaller object?

The force = 1.334 x 10⁴ N

Gravity is a force that arises because of the attraction between objects with mass.  

The magnitude of this attraction is proportional to the mass of the object.  

The greater the mass of the object, the greater the gravitational force  

Relationships can both be stated in  

Newton's Gravity Law:  

with F = gravitational force,  N

G = gravitational constant,  6.67 x 10⁻¹¹ Nm²/kg²

m1, m2 = mass of object,  kg

r = distance between two objects.  m

m₁= 1 kg

m₂=2 x 10²⁰ kg

r = 1 x 10³ m

The force acting on the smaller object=The force acting on the larger object(Newton's Third Law)

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.