Step-by-step explanation:
Two falling inflated balls of different masses land at the same time. They move under the action of gravity and the acceleration due to gravity is independent of the mass of the objects.
A large, massive dog weighs more than a small dog. The weight of an object is given by :
W = mg
So, the force of gravity increases with the mass of the object.
A crumpled ball of paper falls faster than a sheet of paper of the same mass. It is due to air resistance or some drag forces.