* Mass: The more massive an object is, the more force is needed to get it moving. A giant boulder will require much more force than a pebble.
* Friction: The amount of friction acting on an object also plays a huge role. A heavy box on a rough surface will need more force to start moving than a box on a smooth surface.
* Inertia: An object's inertia (its resistance to changes in motion) is directly related to its mass.
So, to figure out which object needs the most energy or force, you need to know:
1. The mass of each object
2. The amount of friction acting on each object
Example:
* A heavy, rusty car parked on a steep hill will require more force to get moving than a lightweight bicycle on a flat, smooth road.
Let me know if you have specific objects in mind, and we can compare them!