Respuesta :

Reducing the distance between them. In theory, also increasing the mass; but you can't really change the mass of an object. However, you can compare the forces if you replace an object by a different object, which has a different mass.

i hope this will work..
Increase object mass or decrease the distance in between objects. Of the two, force is proportional to mass - double the mass, double the force. Distance is to the square - reduce distance to half, force will increase by 4x.