The law of inertia states that an object in motion will stay in motion.
If there is not a change in force the object will nether speed up or slow down.
In space it would be easier to see that all objects fall at the same speed no matter there size.
If there is more force on one side of the object it will go the way the object is forcing it.
IT would be an unbalanced force moving the object.
The formula is net force=mass x acceleration.
If your acceleration increases, your force increases.
If mass increases, acceleration decreases.
For every action there is an equal and opposite reaction.
If an object is at rest it will stay at rest unless an object acts on it.
An objects mass does not effect much it is the force of that object.