sustainable thesaurus. Retrieved October 19, 2015, from http://www.powerthesaurus.org/sustainable/synonyms.
the mass of the object determines the amount of inertia in an object. Mass determines the amount of inertia an object has. It is an object's intrinsic property to resist change. the two main things are speed and velocity. You have to factor in a bunch of smaller things too, but those don't really have much effect.
The definition of inertia is when an object remains still or moves in a constant direction at a constant speed. Inertia will continue unless the object meets some external force. The more inertia an object has, the less the object will change its motion when it meets another force. The ground is the force, the motion, that causes the object to no longer have inertia and to instead stray from its speed and direction.